Ok...so I wanted to revisit the "going solar...is it worth it" and look at my assumptions. Well...one assumption was the 25% energy usage. If I want to maximize my tax deduction, then I should try to get the largest system for my money because the ROI will follow this assumption. Well...the maximum tax deduction is limited by the NC Renewable Energy Personal Tax Credit. This credit is 35% of the installed cost up to a maximum of $10,500. So...if I want to maximize this then my system would need to cost: $10,500/0.35 = $30,000.
So...if I play with the solar-estimate.org calculator, that means my system could be a maximum of about 3.8 kW or roughly 46% of my estimated average annual electricity usage.
Now what's interesting is that the ROI for the system is highly dependent on how you finance the system. I noticed that the default borrowing is set to 30-years...aka a mortgage. And what's interesting is that the more you borrow...the better the ROI. So if you borrow 50% of the cost (they estimate ~$11,000 after tax credits) at 6.5% over 25-years, then the ROI is 4 years. If you borrow 100%, then the ROI is zero years. Why is this? Well...the annual loan payment is less than the sum of the utility savings+NC Greenpower incentives + Duke Energy RECs. As the loan life shortens to say, 5 years, then the ROI creeps up to 10 years.
So essentially what this is says...is if you can refinance your home or purchase your home with some extra cash for the upgrade and put on a solar system, then you'll be golden with zero to one year ROI. The best loan terms I could find were 15 years loans on Home Equity. Other than that most loans are limited to 5 years.
Of course, as my wife says....this is all dependent on if you can even put this on your roof. Who knows what our homeowners association would say about the panels. Lots of folks out there can be ignorant...
Saturday, December 17, 2011
Thursday, December 15, 2011
Enertia Homes and Reblog
OK...so I saw Enertia Homes the first time on the GreenHD network and thought it was uber cool. That was at least a year ago. Well, for some raeson, I just remembered about it and started looking at it. It's a pretty awesome concept. Here's the link to the MFR website: http://enertia.com/
They are located in NC and they produce very low energy (maybe net-zero in certain locatiosn) homes paired with solar hot water and solar PV. The homes use a doube-envelope system to heat and cool the house in lieu of an HVAC system. Well..in NC, I'm sure we'll at least want a dehumidifier. Oh...and if you have a picky spouse...then maybe you'll want a small HVAC system. However, you could go ahead and install a small geothermal system to minimize those costs...maybe even help the hot water generation too.
On the website, they do have information on energy usage for a house in Durham, NC. They spent a total of $572 over the year for the home (~$48/month). That's not too shabby...
And heres a reblog from another fellow blogger about the homes.
http://sustainablog.blogspot.com/2007/07/enertia-home-modern-marvel-or-lot-of.html
As they've said...there's not a lot of data on these homes...and then there's apparently a fire risk too.
I may just look into beefing up the insulation in my walls using this retrofoam stuff. It can be installed into existing wall cavities that already have insulation in them. That's pretty cool...but it really depends on how much is costs to install and if there's any ROI. If you consider my average utility bill is probably around $70/month...then even reducing it by 50% would save me $420/year. If installing the retrofoam cost me $7,000 to install (probably not unrealistic...I had a quote to encapsulate my crawl space that was $7,000 which included the liner, dehumidier, spray foam, etc. A second quote with everything but the spray foam was $2800..so $4200 just for the spray foam in my crawl space) then the ROI is 16.7 years.
Given that, it would be more cost effective to go solar as I said in my previous posting. That would give me an ROI of 9 years...
They are located in NC and they produce very low energy (maybe net-zero in certain locatiosn) homes paired with solar hot water and solar PV. The homes use a doube-envelope system to heat and cool the house in lieu of an HVAC system. Well..in NC, I'm sure we'll at least want a dehumidifier. Oh...and if you have a picky spouse...then maybe you'll want a small HVAC system. However, you could go ahead and install a small geothermal system to minimize those costs...maybe even help the hot water generation too.
On the website, they do have information on energy usage for a house in Durham, NC. They spent a total of $572 over the year for the home (~$48/month). That's not too shabby...
And heres a reblog from another fellow blogger about the homes.
http://sustainablog.blogspot.com/2007/07/enertia-home-modern-marvel-or-lot-of.html
As they've said...there's not a lot of data on these homes...and then there's apparently a fire risk too.
I may just look into beefing up the insulation in my walls using this retrofoam stuff. It can be installed into existing wall cavities that already have insulation in them. That's pretty cool...but it really depends on how much is costs to install and if there's any ROI. If you consider my average utility bill is probably around $70/month...then even reducing it by 50% would save me $420/year. If installing the retrofoam cost me $7,000 to install (probably not unrealistic...I had a quote to encapsulate my crawl space that was $7,000 which included the liner, dehumidier, spray foam, etc. A second quote with everything but the spray foam was $2800..so $4200 just for the spray foam in my crawl space) then the ROI is 16.7 years.
Given that, it would be more cost effective to go solar as I said in my previous posting. That would give me an ROI of 9 years...
Thursday, December 8, 2011
December Energy Bill
Wow...I sure have been slacking on the ole' blog front. My bad...
Anyhow, I got in our latest energy bill for December (OK...really its for November, but the bill date is December). Here's the results:
Total kWH = 963 (2010 = 1374)
Days = 30
Avg kWh/d = 32.10/day (2010 = 45.8 kWh/d)
% Savings vs 2010 = 29.9%
% Savings compared to former 1300 sf townhome = 108.3%
OK...so the trend continues. We've consistently been around 30-40% savings versus 2010 while using about the same energy as our former (half-sized) townhome.
Winter promises to hold the largest savings. Look at the energy used last year:
Jan 2010 = 3,224 kWh (94.8 kWh/d)
Feb 2010 = 1967 kWh (70.2 kWh/d)
The largest energy usage day we've had was a couple days ago. It was in the high 30s, low 40s....we did 4 loads of laundry (re: dryer) ...and we cooked a lot. On that day we used 60 kWh. Our largest average month (July) has been 32.9 kWh/d. So keeping up with this pattern would mean that we're looking at the potential for savings in the range of 50-67%. Only time will tell how well we do.
Anyhow, I got in our latest energy bill for December (OK...really its for November, but the bill date is December). Here's the results:
Total kWH = 963 (2010 = 1374)
Days = 30
Avg kWh/d = 32.10/day (2010 = 45.8 kWh/d)
% Savings vs 2010 = 29.9%
% Savings compared to former 1300 sf townhome = 108.3%
OK...so the trend continues. We've consistently been around 30-40% savings versus 2010 while using about the same energy as our former (half-sized) townhome.
Winter promises to hold the largest savings. Look at the energy used last year:
Jan 2010 = 3,224 kWh (94.8 kWh/d)
Feb 2010 = 1967 kWh (70.2 kWh/d)
The largest energy usage day we've had was a couple days ago. It was in the high 30s, low 40s....we did 4 loads of laundry (re: dryer) ...and we cooked a lot. On that day we used 60 kWh. Our largest average month (July) has been 32.9 kWh/d. So keeping up with this pattern would mean that we're looking at the potential for savings in the range of 50-67%. Only time will tell how well we do.
Monday, November 7, 2011
November Energy Bill
I got the latest Energy bill in yesterday. Here's the results:
Nov 2011-
Total KWH: 734
Days: 29
Avg KWH/d: 25.30
2010 Avg Kwh/d: 26.28
Savings: 3.67%
Comparing to 2009 townhome: 108.1%
Yup...not a huge savings. But then recall, the bill is label November, but it's actually for October 4 - November 2nd. Well...for about half of October, the HVAC system was turned off. Then we started getting those cold nights (30s-40s) so the heat was turned on. Those cold temperatures are unusual for this time of the year (did you guys see the October New England snow storm?)
Overall, I think we're fine. Now NEXT month is going to be exciting. As a preview, last year we used 1374 kWh for the month or 45.80 kWh/d. We're averaging 32.2 kWh/d right now...and that will be back to the normal ~30% savings. After that in January we used 3,224 kWh and in February it was 1,967 kWh....I expect HUGE savings over those months. Since we've installed the Geothermal system, our largest month was 1086 kWh...
Nov 2011-
Total KWH: 734
Days: 29
Avg KWH/d: 25.30
2010 Avg Kwh/d: 26.28
Savings: 3.67%
Comparing to 2009 townhome: 108.1%
Yup...not a huge savings. But then recall, the bill is label November, but it's actually for October 4 - November 2nd. Well...for about half of October, the HVAC system was turned off. Then we started getting those cold nights (30s-40s) so the heat was turned on. Those cold temperatures are unusual for this time of the year (did you guys see the October New England snow storm?)
Overall, I think we're fine. Now NEXT month is going to be exciting. As a preview, last year we used 1374 kWh for the month or 45.80 kWh/d. We're averaging 32.2 kWh/d right now...and that will be back to the normal ~30% savings. After that in January we used 3,224 kWh and in February it was 1,967 kWh....I expect HUGE savings over those months. Since we've installed the Geothermal system, our largest month was 1086 kWh...
Thursday, November 3, 2011
Cost of Going Solar...is it worth it?
Ok...so I've been mulling over additional ways to save money. If you've been following...that's included changing out the HW heater for one. I've also been thinking about replacing the siding on my house (which is the old Masonite stuff...which had a lawsuit against it...which expired right after I bought my home)...whch would include Housewrap which should reduce energy bills by 10-15%.
The other thing, I've been thinking about is solar power. Adding this in would significantly reduce my bills...but at a significant cost. So I did some research and came upon a handy website that allowed me to determine the cost of solar. This saves me a lot of heartache of doing it myself...and it appears to be fairly comprehensive. The site is: solar-estimate.org and its a free site that is run by "Energy Matters LLC" which makes web-based tools for marketing and sales in solar, wind, renewable energy, and energy efficiency industries. So given that this site was probably paid for by a professional organization looking to advance the industry and not one specific business, I feel fairly comfortable using the tool.
So, I input my location, selected my Utility, along with some other minor stuff (residence, I want to review solar PV, etc) and it says I have a solar rating of "GREAT" at 5.09 kWh/m^2/day. I've seen this value before and when I look at those "solar maps", my area is right around 5, so this makes sense to me. This is the "average solar radiation during an average year". Next I entered the following information:
The other thing, I've been thinking about is solar power. Adding this in would significantly reduce my bills...but at a significant cost. So I did some research and came upon a handy website that allowed me to determine the cost of solar. This saves me a lot of heartache of doing it myself...and it appears to be fairly comprehensive. The site is: solar-estimate.org and its a free site that is run by "Energy Matters LLC" which makes web-based tools for marketing and sales in solar, wind, renewable energy, and energy efficiency industries. So given that this site was probably paid for by a professional organization looking to advance the industry and not one specific business, I feel fairly comfortable using the tool.
So, I input my location, selected my Utility, along with some other minor stuff (residence, I want to review solar PV, etc) and it says I have a solar rating of "GREAT" at 5.09 kWh/m^2/day. I've seen this value before and when I look at those "solar maps", my area is right around 5, so this makes sense to me. This is the "average solar radiation during an average year". Next I entered the following information:
From above, nearly all of this stuff was pre-filled in for me. Note that I said I only wanted to put in a 25% system (2kW)...since if I did do this, I'd want to start off small. The install cost shown is from a help file that shows its about $9/WDC <2 kW installed and $8/WDC for systems =>2kW. Note that my utility inflation rate was suggested at 3.78% based on whatever data, solar-estimate.org has. This actually is probably pretty close. I've looked this value up numeous times for Engineering reports and, in general, Utility inflation is about 4%. So I'm comfortable with this.
So after, I put this stuff, in I got the following for system sizing:
The energy bill is right on. When I track my energy bills via Mint.com, I get roughly the same. OK...so this says I'd need roughly a 2.25 kW system and I'd need 226 ft2 of roof area. Note:. 2.25kW is roughly how much energy my geothermal system needs when its running (for half...so either the upstairs or the downstairs). .How big is 226 ft2? If I assume a 4-ft long solar panel and I put 2 end-to end, then I'd need an area that's 8-ft x 28-ft. That's really not all that big. This estimates an annual production of just under 3000 kWh. Note that there is some hidden math behind here...because this is not just simply: 226 ft2 --> 21m2 x 5.09 kWh/m2/day * 365 days/yr...because this equals 39,000 kWh/yr. The 226ft2 (or 21m2) is based on 10W/ft2 average solar panel sizing. So this obviously has some fairly high conservatism in it. I get fairly similar values when I run the Dept of Energy's PV Watts...this gives me a solar rating of 5.07 kWh/m2/day and an energy production of 2976 kWh/yr. If I use data from an existing PV system (adjacent to the fire station roughly 2.5 miles away, I get 4.91 kWh/m2/day and and equivalent annual production of 2863 kWh. So this is neighborhood.
Next it gave the rough cost for the system:
$18.1K? Installed cost? OK...I can believe that. I've heard numbers floating around and this makes sense to me. The next part is really cool...they show me how the incentives work. I've seen these before since I got the same one's for my geothermal system...for exception of the Duke Energy and NC Greenpower adders:
Overall...this is showing my a rough ROI of 9 years. That's not overly great...but then again, it's not overly bad either. Most of my other options (i.e. HW Heater) don't have an ROI for 10+ years. The information below gets into more detail on the savings.
Overall...this appears to be a good investment if you take into account the 25-yr net present worth. So maybe someday, I'll have some extra cash on hand and I'll look into this. Also...possibly by then...prices of solar panels will have come down helping the ROI. I definitely like the idea.
One thing I'm still tentative about is what maintenance needs to occur. Do I need to go up to my roof every fall and get the leaves off? Do I need to wash the system (espeically if a bird decides to unload)? Anything else I need to do?
When and if I install a system....I'm sure I'll blog about it...so you'll know.
Any thoughts out there?
Wednesday, November 2, 2011
Brrrrr...
Hello all-
It's gotten cold in the Carolina's the past couple weeks. Morning temperatures have been flirting with the high 30s...with afternoon temperatures in the high 50s, low 60s. You know what that means....the heat is on. Below is the TED historical usage. Electricity usage is up into the 30 kWH/d range. Those days that show usage in the 40 KWH/d are when we're doing laundry (Sunday/Monday). It's amazing how much the eletric dryer uses even though we have a high efficiency washer which really spins the water out of the clothes. Maybe I'll investigate the default settings on the dryer to see if I can save some energy there...but I kind of doubt I'll find anything.
My HW usage is up too...not suprising as anyone can tell you how nice a hot shower is on a cold AM....even though I have the super-low flow 1.5 gpm showerhead. And now I have the results to show it (see below). On average we're using about $0.50-$0.60 per day on HW. One an avearage month...that's $15 in my Bill. Probably at best, I can reduce that by about 50% if I upgrade my HW heater to one of those GE Geospring Units and run it in series with my existing HW (turned off) to maximize the geothermal desuperheater. At that amount ($7.50/mo), I'd save $90/year. Thus it would take roughly 10 years to pay off the HW heater. That's not exactly a great ROI, but who knows...maybe prices will drop to make it more attractive. I really wish Duke Energy would offer a rebate on higher efficiency hot water heaters to make it worthwhile. A $300 rebate would mean 3 years off the ROI, which is great. But...Duke energy's program is for HVAC only...bah!
FYI...so the NC Utilities commission, denied Duke Energy's request for the 15.4% rate increase this year. Instead they recommended a ~5% increase. Duke's pretty pissed about this and I'm sure they'll find another way to get the rates out of us. Maybe I'll need to start really looking at solar panels soon...
It's gotten cold in the Carolina's the past couple weeks. Morning temperatures have been flirting with the high 30s...with afternoon temperatures in the high 50s, low 60s. You know what that means....the heat is on. Below is the TED historical usage. Electricity usage is up into the 30 kWH/d range. Those days that show usage in the 40 KWH/d are when we're doing laundry (Sunday/Monday). It's amazing how much the eletric dryer uses even though we have a high efficiency washer which really spins the water out of the clothes. Maybe I'll investigate the default settings on the dryer to see if I can save some energy there...but I kind of doubt I'll find anything.
 |
| TED Historical Usage up to 11/2/2011 |
My HW usage is up too...not suprising as anyone can tell you how nice a hot shower is on a cold AM....even though I have the super-low flow 1.5 gpm showerhead. And now I have the results to show it (see below). On average we're using about $0.50-$0.60 per day on HW. One an avearage month...that's $15 in my Bill. Probably at best, I can reduce that by about 50% if I upgrade my HW heater to one of those GE Geospring Units and run it in series with my existing HW (turned off) to maximize the geothermal desuperheater. At that amount ($7.50/mo), I'd save $90/year. Thus it would take roughly 10 years to pay off the HW heater. That's not exactly a great ROI, but who knows...maybe prices will drop to make it more attractive. I really wish Duke Energy would offer a rebate on higher efficiency hot water heaters to make it worthwhile. A $300 rebate would mean 3 years off the ROI, which is great. But...Duke energy's program is for HVAC only...bah!
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| TED HW Usage - Oct 31, 2011 |
Sunday, October 9, 2011
October Bill
Howdy folks-
The good news just keeps coming. This month's bill came in at 771 kW over 32 days or 24.1 kWh/d. That's ~35% under last year's bill of 37 kWh/d. That's to be expected since we've averaged 35% under for the past 5 months. Compared to our former townhome, we're 4% over. Can't complain...overall itsFantastic!
I expected the next couple months to not be as great because we're moving into Fall and the HVAC system will most likely not turn on at all. There have been some cold nights recently with my wife turning on the heat a couple of mornings (Brrr).
I've graphed my energy usage since 2009 below. Some things to note:
Jan 2009 - March 2010 we were still in our 2005, 1300 sf townhome.
Then in April 2010, we moved into our current home (1984, 2700sf).
Finally, in April 2011, we installed the geothermal heat pump.
The energy savings is fairly obvious (green bars starting in April, month 4). What's pretty cool is that you can see how efficient our home is compared to our previous townhome which was newer (2005) and less than half the size (red bars). Neat-o, huh?
Now I need to anticipate what Winter's going to bring. Supposedly, the geothermal system is significantly more efficient in heating mode than cooling mode. It's said that its somewhere around 67-80% more efficient. Only time will tell...
The good news just keeps coming. This month's bill came in at 771 kW over 32 days or 24.1 kWh/d. That's ~35% under last year's bill of 37 kWh/d. That's to be expected since we've averaged 35% under for the past 5 months. Compared to our former townhome, we're 4% over. Can't complain...overall itsFantastic!
I expected the next couple months to not be as great because we're moving into Fall and the HVAC system will most likely not turn on at all. There have been some cold nights recently with my wife turning on the heat a couple of mornings (Brrr).
I've graphed my energy usage since 2009 below. Some things to note:
Jan 2009 - March 2010 we were still in our 2005, 1300 sf townhome.
Then in April 2010, we moved into our current home (1984, 2700sf).
Finally, in April 2011, we installed the geothermal heat pump.
The energy savings is fairly obvious (green bars starting in April, month 4). What's pretty cool is that you can see how efficient our home is compared to our previous townhome which was newer (2005) and less than half the size (red bars). Neat-o, huh?
Now I need to anticipate what Winter's going to bring. Supposedly, the geothermal system is significantly more efficient in heating mode than cooling mode. It's said that its somewhere around 67-80% more efficient. Only time will tell...
Sunday, September 25, 2011
Flash-back...sealing my home
Ok...so I know I've promised this for a while and I've finally gotten my ducks in a row. So...be prepared to go back in time and see some of my initial work sealing my home....scooby-doo style. Key the wavy lines:
<<>>><<<>>><<<>>><<<>><<>>><<<>><<>>><<>>><<>><<>><<>>><<<>>><<>>><<>>>
So when I got my initial energy audit (a birthday present from my wife...she's awesome), there were a handful of key things that I needed to do. Kudos to ProEnergy and Eric Wall for performing the audit. And again to my beautiful wife for getting me an awesome present. OK...below I'll discuss two fixes:
First up...I had no door sweeps. Seriously...none of my doors. When I got down onto the floor, I could look outside. On one door...my backdoor...the opening had to be at least 1/4". The fix was simple...install door sweeps. Of course, only one of my doors as a standard sized...so when I bought the door sweeps from Lowe's, I had to do some sawing. It was no big deal...but it wasn't totally painless. For the majority of my doors I bought the door sweep that attached to the outside of the door so when the rubber wears out I can get at it easily. Not surprising...it makes a big difference...and there's no highway for bugs to enter the house either.
The second big thing we needed to fix was found using the thermal gun. And I kind of knew something was up in my bonus room (i.e. finished room above the garage) when it was significantly warmer (10F) than the rest of the house. Well...apparently there was insulation missing in the ceiling of the bonus room. And truthfully...the pictures looked as if a little kid grab random pieces and ripped them out. On top of that, while there was insulation in the attic storage areas on either side of the room...that didn't stop the air movement. So to fix this, I had an insulation company come in and replace the insulation. They included a vent to maintain air movement when is good. Then the fun stuff began. Below is a pic of the bonus room attic space before:
The pic below is a picture of the work in progress with my wife. What we did was install rigid styrofoam insulation on the outer joists and then seal the joints with HVAC tape. What this did was provide another layer of insulation (this stuff is R5) as well as stop the air movement.
Once we did this to the walls, I added insulation to the doors (there was none), put on weather stripped to the doors (there was nothing there either), and we installed radiant barrier on the opposite joists. Oh yeah...I also had to do some caulking on the molding around the door to stop air leaks there as well. All of this had a profound effect. Oh...and I found my ventilation fan in the attic above the bonus room was broken too...I had to replace the motor on the fan. And while I was at it I changed out the thermostat too. OK...so the temperature in that room now is only about 2 degrees different from the rest of the house. And when I had the energy audit guys back, they could easily see the difference on the thermal camera.
This fix was fairly easy and took about a day to do...and I know it's paying dividends. That's because when I walk the dog I see my neighbors with a window air conditioner sticking out of the window of their bonus room. And talking with HVAC guys, they typically up-size systems or install dedicated units just for bonus rooms. Yet...maybe all you need to do is some minor modifications and it'll do just fine.
So for any folks out there who have a similar issue...try this stuff first. It worked for me...
Friday, September 23, 2011
LED Light Bulbs
Ok...as I'm sure most of you may expect, nearly all my light bulbs in my home are energy efficient. Nearly all are CFLs throughout the house....nearly all are 13W with only a couple being 23W (outdoor lights). There's only 5 lights that are not:
1) Master Bedroom ceiling fan. I have 1 @ 40W bulb here. For some reason the CFLs flicker...and I've tried all the 'fixes' online and none work. So I'm stuck with the 40W bulbs. At least I'm only using 1 bulb instead of 2.
2) Dining Room chandelier. It's dimmable and has 5 @ 40W bulbs.
3) Breakfast Nook chandelier. Same as #2, but has 6 @ 40W bulbs
4) Kitchen track lighting. It's dimmable and has 5 @ 50W GU10 bulbs
5) Entry way chandelier. 3 @ 40W bulbs.
Out of all these lights, the Kitchen and breakfast nook lights are what I use by far the most. As I'm typing this I'm glancing at my TED5000 seeing the two lights...dimmed...still using about 350W. Ugh!
So changing these two lights out...11 bulbs...could provide some good savings. However, I just can't stomach paying the high prices for light bulbs. A non-dimmable Chandelier CFL light bulb is $4 each. That's at least fairly reasonable...I could probably switch out the Entry Way chandelier with these. But not my two dimmable chandeliers. A 5W (25W equivalent) dimmable CFL light bulb is $8 each. It's $15 for a LED version (4W) nondimmable bulb. To get dimmable...$23. So, if I wanted to go LED, it would cost me $138 to replace the one dimmable chandeliers. Seriously?!? To replace my kitchen lighting with dimmable LED GU10 bulbs is $32 EACH. That's another $160. Total = $298....before shipping and taxes. Adding in the other dimmable chandelier would add in another $115 for $413 total.
I just don't think I can stomach this. I know there's the math that says they pay for themselves....but I just need to check for myself.
So let's take the kitchen light...5 @ 50W light bulbs = 250W when on @ full power (side note: with the dimmer I'm rarely at full power). Talking with my wife...let's assume it's on 3 hrs/day on average. That's 750Wh/d or $0.075/day at $0.10/kWh. On average that's $2.28/month or $27.38/year. A new LED light bulb appears to be 6.5W for a 50W 'equivalent'. That equates to 97.5Wh/d or $0.00975/day or $3.56/yr. So annual savings on this light would be $23.82. Thus, my return on investment would be: $160/23.82 = 6.72 years. That's a pretty dang long time for a light bulb. Now the dimmable LED light bulb claims that it'll last 25,000 hours (http://www.polar-ray.com/GU10-LED-Bulbs_c_159.html). I've seen this before...my CFL's "claim" they'll last 12,000 hours....and I have yet to be convinced (I've replaced burned out CFLs). OK...so 25,000 hours is equivalent to 2.85 years if run 24/7. Converting to 3 hrs/day that's 22.83 years. So, even cutting this in half to ~11.4 years still shows the bulbs will pay for themselves.
Still...I think I'm going to wait until prices are more reasonable. It's said that prices are falling rapidly...so maybe once my ROI is closer to 2-3 years will I decide to 'splurge'. Until then...I think I'll just deal with my $2.28/mo....and truthfully it's going to be less than that because I use my dimmer...a lot. I'm constantly turning the lighting down (with my wife doubling-back to turn it back up...and then I'm back...etc, etc). It sure would be nice to not have to worry constantly about those lights...
1) Master Bedroom ceiling fan. I have 1 @ 40W bulb here. For some reason the CFLs flicker...and I've tried all the 'fixes' online and none work. So I'm stuck with the 40W bulbs. At least I'm only using 1 bulb instead of 2.
2) Dining Room chandelier. It's dimmable and has 5 @ 40W bulbs.
3) Breakfast Nook chandelier. Same as #2, but has 6 @ 40W bulbs
4) Kitchen track lighting. It's dimmable and has 5 @ 50W GU10 bulbs
5) Entry way chandelier. 3 @ 40W bulbs.
Out of all these lights, the Kitchen and breakfast nook lights are what I use by far the most. As I'm typing this I'm glancing at my TED5000 seeing the two lights...dimmed...still using about 350W. Ugh!
So changing these two lights out...11 bulbs...could provide some good savings. However, I just can't stomach paying the high prices for light bulbs. A non-dimmable Chandelier CFL light bulb is $4 each. That's at least fairly reasonable...I could probably switch out the Entry Way chandelier with these. But not my two dimmable chandeliers. A 5W (25W equivalent) dimmable CFL light bulb is $8 each. It's $15 for a LED version (4W) nondimmable bulb. To get dimmable...$23. So, if I wanted to go LED, it would cost me $138 to replace the one dimmable chandeliers. Seriously?!? To replace my kitchen lighting with dimmable LED GU10 bulbs is $32 EACH. That's another $160. Total = $298....before shipping and taxes. Adding in the other dimmable chandelier would add in another $115 for $413 total.
I just don't think I can stomach this. I know there's the math that says they pay for themselves....but I just need to check for myself.
So let's take the kitchen light...5 @ 50W light bulbs = 250W when on @ full power (side note: with the dimmer I'm rarely at full power). Talking with my wife...let's assume it's on 3 hrs/day on average. That's 750Wh/d or $0.075/day at $0.10/kWh. On average that's $2.28/month or $27.38/year. A new LED light bulb appears to be 6.5W for a 50W 'equivalent'. That equates to 97.5Wh/d or $0.00975/day or $3.56/yr. So annual savings on this light would be $23.82. Thus, my return on investment would be: $160/23.82 = 6.72 years. That's a pretty dang long time for a light bulb. Now the dimmable LED light bulb claims that it'll last 25,000 hours (http://www.polar-ray.com/GU10-LED-Bulbs_c_159.html). I've seen this before...my CFL's "claim" they'll last 12,000 hours....and I have yet to be convinced (I've replaced burned out CFLs). OK...so 25,000 hours is equivalent to 2.85 years if run 24/7. Converting to 3 hrs/day that's 22.83 years. So, even cutting this in half to ~11.4 years still shows the bulbs will pay for themselves.
Still...I think I'm going to wait until prices are more reasonable. It's said that prices are falling rapidly...so maybe once my ROI is closer to 2-3 years will I decide to 'splurge'. Until then...I think I'll just deal with my $2.28/mo....and truthfully it's going to be less than that because I use my dimmer...a lot. I'm constantly turning the lighting down (with my wife doubling-back to turn it back up...and then I'm back...etc, etc). It sure would be nice to not have to worry constantly about those lights...
Tuesday, September 20, 2011
Hot Water Heater
So I've been trying to figure out what else I need to do to reduce my energy usage. There's things like:
1) Install high efficiency hot water heater
2) Replace siding on the house and put on house wrap
3) Install solar panels
4) Replace fridge
5) etc.
Well...I don't have a ton of money to spend so #2 and #3 are automatically out as those cost multiple thousands of dollars...if not above $10k. That leaves me with the fridge and HW heater. Well...at most the fridge might cost me $60-70/yr. And while I could get a bigger fridge that is more energy efficient...I'd still only save maybe $5-$10/yr. Yeah...that's not worth it. So that really leaves me with looking at the HW heater. I checked out TED from the last 48 hrs and it looks like the HW heater runs roughly 7x/day for about 10 minutes. The Geothermal system is not operating...it's that nice fall weather so I'm not heating or cooling. That also means the desuperheater is not generating hot water. At 4.8kW, that means the HW heater is using 5.6kWh/day. And I'm currently using 22 kWh/d. Thus, my HW is accounting for ~25% of my current total daily electricity usage. Obviously that value will change with increased HVAC usage...but its the numbers I have now.
OK...so one of those hybrid hot water heaters (http://www.geappliances.com/heat-pump-hot-water-heater/ claims a 62% reduction in energy usage compared to a standard hot water heater. I verified this by looking at that yellow tag energy information. My current 50-gal HW heater says it'll cost me $520/year and 4879 kWh/year. The hybrid says $198/yr and 1856 kWh/yr. There's lots of assumptions included in there (family of 4, using XX gallons per day, $0.105/kWh, yadda yadda)...but let's assume that this is relative and be scalable to my usage. I can't see why it wouldn't since it's based on usage.
This would mean I could expect my energy usage to reudce from 5.6kWh/day to 2.1 kWh/d. From a cost standpoint, that's $66/year in savings. My return on investment: $1000-$300 (tax rebate) = $700/$66 = 10.6 years. Not a great return, but it's a return...and its within a 'lifetime'. I should note that next year my electricity rates are going up 15%. And Dook Energy is trying to raise them another 15% the following year. Using just the one rate increases bring my savings up to $76/yr and make my ROI to 9.2 years.
One thing I should also note is that the hybrid HW heater is essentially an air source heat pump (ASHP) attached to a hot water heater. So when it runs...it's essentially an air conditioner. It's taking the heat from the air and transferring it to the hot water. That means my crawl space (where my HW heater is located) will become 'conditioned'. So no more dehumidifier needed (that's an extra 3 kWh/d minimum which isn't included here). So that's cool.
However, I'm a little worried if there's enough 'heat' down in the crawl space during the winter. I know last winter, the crawl space hung around 68F...and I had crappy vents in there. I know i probably had duct leakage...but it wasn't too signficant as I had the energy audit guys down there and I fixed the places that had bad leakage. I was reading online and some folks saw the unit drop temperatures down to 45-47F in their basements....which required them to drop a duct to give it some heat.
So I'm thinking what I'll do this winter is I'll insulated the door to he crawl space and then monitor the temperature in the crawl space to see what happens. If temperatures stay fairly warm, maybe I'll swap out the hot water heater...
Any thoughts out there?
UPDATE: Now there's always switching to gas to save moeny. But that's not cheap either. First, my hot water heater is in my crawl space. And I'd need to vent the exhaust....which I doubt I have space for. So for a standard gas hot water heater, I'd probably have to move it someplace else (garage?)...and I'd need an electrician and plumber for that. And that isn't cheap. I could go tankless and gas. Again I'd need to move things around...and that unit is ~$1500. And a 7.4 gpm unit ("2 uses") would still cost $223/mo @ 1.22/therm (using the Energy Guide). So its still not better than the hybrid uni...not to mention it'll be more expensive to purchase and install.
UPDATE 2: I just found this in the WaterFurnace Desuperheater User manual. Apparently, it's more efficient to install two HWs in series to allow the first one to be a preheat tank to maximize the desuperheater usage. I'll definitely have to think about this...
1) Install high efficiency hot water heater
2) Replace siding on the house and put on house wrap
3) Install solar panels
4) Replace fridge
5) etc.
Well...I don't have a ton of money to spend so #2 and #3 are automatically out as those cost multiple thousands of dollars...if not above $10k. That leaves me with the fridge and HW heater. Well...at most the fridge might cost me $60-70/yr. And while I could get a bigger fridge that is more energy efficient...I'd still only save maybe $5-$10/yr. Yeah...that's not worth it. So that really leaves me with looking at the HW heater. I checked out TED from the last 48 hrs and it looks like the HW heater runs roughly 7x/day for about 10 minutes. The Geothermal system is not operating...it's that nice fall weather so I'm not heating or cooling. That also means the desuperheater is not generating hot water. At 4.8kW, that means the HW heater is using 5.6kWh/day. And I'm currently using 22 kWh/d. Thus, my HW is accounting for ~25% of my current total daily electricity usage. Obviously that value will change with increased HVAC usage...but its the numbers I have now.
OK...so one of those hybrid hot water heaters (http://www.geappliances.com/heat-pump-hot-water-heater/ claims a 62% reduction in energy usage compared to a standard hot water heater. I verified this by looking at that yellow tag energy information. My current 50-gal HW heater says it'll cost me $520/year and 4879 kWh/year. The hybrid says $198/yr and 1856 kWh/yr. There's lots of assumptions included in there (family of 4, using XX gallons per day, $0.105/kWh, yadda yadda)...but let's assume that this is relative and be scalable to my usage. I can't see why it wouldn't since it's based on usage.
This would mean I could expect my energy usage to reudce from 5.6kWh/day to 2.1 kWh/d. From a cost standpoint, that's $66/year in savings. My return on investment: $1000-$300 (tax rebate) = $700/$66 = 10.6 years. Not a great return, but it's a return...and its within a 'lifetime'. I should note that next year my electricity rates are going up 15%. And Dook Energy is trying to raise them another 15% the following year. Using just the one rate increases bring my savings up to $76/yr and make my ROI to 9.2 years.
One thing I should also note is that the hybrid HW heater is essentially an air source heat pump (ASHP) attached to a hot water heater. So when it runs...it's essentially an air conditioner. It's taking the heat from the air and transferring it to the hot water. That means my crawl space (where my HW heater is located) will become 'conditioned'. So no more dehumidifier needed (that's an extra 3 kWh/d minimum which isn't included here). So that's cool.
However, I'm a little worried if there's enough 'heat' down in the crawl space during the winter. I know last winter, the crawl space hung around 68F...and I had crappy vents in there. I know i probably had duct leakage...but it wasn't too signficant as I had the energy audit guys down there and I fixed the places that had bad leakage. I was reading online and some folks saw the unit drop temperatures down to 45-47F in their basements....which required them to drop a duct to give it some heat.
So I'm thinking what I'll do this winter is I'll insulated the door to he crawl space and then monitor the temperature in the crawl space to see what happens. If temperatures stay fairly warm, maybe I'll swap out the hot water heater...
Any thoughts out there?
UPDATE: Now there's always switching to gas to save moeny. But that's not cheap either. First, my hot water heater is in my crawl space. And I'd need to vent the exhaust....which I doubt I have space for. So for a standard gas hot water heater, I'd probably have to move it someplace else (garage?)...and I'd need an electrician and plumber for that. And that isn't cheap. I could go tankless and gas. Again I'd need to move things around...and that unit is ~$1500. And a 7.4 gpm unit ("2 uses") would still cost $223/mo @ 1.22/therm (using the Energy Guide). So its still not better than the hybrid uni...not to mention it'll be more expensive to purchase and install.
UPDATE 2: I just found this in the WaterFurnace Desuperheater User manual. Apparently, it's more efficient to install two HWs in series to allow the first one to be a preheat tank to maximize the desuperheater usage. I'll definitely have to think about this...
Friday, September 16, 2011
TED is back
Woohooo! It ended up being a broken daugherboard. But it's all fixed and my display is back. Now back to being informed and nit-picky about where my electricity is being used...
Friday, September 9, 2011
September Duke Energy Bill
Yes folks, yet another month has passed and I was waiting at the mailbox eager with anticipation...for a bill. This month's electric bill came in and showed continued fantastic results:
Electricity Usage: 941 kWh
Days: 31
Avg Usage: 30.3 kWh/day
Comparing versus 2010: 37% savings (aka reduction in energy usage)
Comparing versus townhome of less than half this houses area (2009): 6% higher.
I'm thrilled. It appears that we've had a consistent ~40% reduciton in energy usage. And, I'm using about the same amount of total energy as if I were still in my former townhome. Just sweet!
I would expect the savinsg to be more if I can figure out where the humidity is coming from in my crawl space. I have the dehumidifier running 6 hrs on/6 hrs off. During that time, the humidity drops to 45% when on...then raises to about 55-60% when off. I'm not sure but it might be hitting the 45% humidity mark and turning off. I need to check the manual to figure this out. UPDATE: Yes, I verified this and once it hits around 45% (the setting on the unit is 50%), it turns off....and then restarts again when the humidity increases.
UPDATE on TED: Energy Inc (the MFRs of the TED unit) sent me a new display. Well, that one didn't work...it wouldn't connect to my gateway. After discussions with tech support, apparently they sent me the wrong model (there is a series 21 and a series 20...I have a series 20). That should arrive today. It'll be nice to have the ole' TED display around again...
UPDATE 2: FYI, my TED unit had 993 kWh for the month vs the 941 for Duke Energy. That's a ~5% error difference. I think the # of days was the same...but I think TED is setup to record from the 2nd to the 2nd, while Duke Energy this month went from the 6th to the 6th.
UPDATE 3: Well, the TED display arrived and this time it showed it was picking up a wireless signal, but again, it was not showing the data. Hrmmph! We'll see Tech support says this time. I have a feeling it's a firmware issue.
UPDATE 4: FYI...I have no idea why my August post is in front of my September post. Maybe once I update this post it'll move it ahead...maybe...I hope...
UPDATE 5: I finally fixed that August post...someone is double-posted...so I just deleted it. So very odd...
Electricity Usage: 941 kWh
Days: 31
Avg Usage: 30.3 kWh/day
Comparing versus 2010: 37% savings (aka reduction in energy usage)
Comparing versus townhome of less than half this houses area (2009): 6% higher.
I'm thrilled. It appears that we've had a consistent ~40% reduciton in energy usage. And, I'm using about the same amount of total energy as if I were still in my former townhome. Just sweet!
I would expect the savinsg to be more if I can figure out where the humidity is coming from in my crawl space. I have the dehumidifier running 6 hrs on/6 hrs off. During that time, the humidity drops to 45% when on...then raises to about 55-60% when off. I'm not sure but it might be hitting the 45% humidity mark and turning off. I need to check the manual to figure this out. UPDATE: Yes, I verified this and once it hits around 45% (the setting on the unit is 50%), it turns off....and then restarts again when the humidity increases.
UPDATE on TED: Energy Inc (the MFRs of the TED unit) sent me a new display. Well, that one didn't work...it wouldn't connect to my gateway. After discussions with tech support, apparently they sent me the wrong model (there is a series 21 and a series 20...I have a series 20). That should arrive today. It'll be nice to have the ole' TED display around again...
UPDATE 2: FYI, my TED unit had 993 kWh for the month vs the 941 for Duke Energy. That's a ~5% error difference. I think the # of days was the same...but I think TED is setup to record from the 2nd to the 2nd, while Duke Energy this month went from the 6th to the 6th.
UPDATE 3: Well, the TED display arrived and this time it showed it was picking up a wireless signal, but again, it was not showing the data. Hrmmph! We'll see Tech support says this time. I have a feeling it's a firmware issue.
UPDATE 4: FYI...I have no idea why my August post is in front of my September post. Maybe once I update this post it'll move it ahead...maybe...I hope...
UPDATE 5: I finally fixed that August post...someone is double-posted...so I just deleted it. So very odd...
Tuesday, August 30, 2011
Waiting on TED
Sorry for the delay. Still waiting on my TED display unit to show back up...and it's killing me. I'm still saving money...but I'm missing my display and its information. I can still see the data using my laptop or cell phone...but there's nothing like the 'glance' at the counter. I can say, that according to TED, I'm using less electricity than last month. It'll be another 3-5 days until I get my next Duke Energy bill and I'll know for sure.
Keep those fingers crossed.
UPDATE: I added a comment to my 'support ticket' and they just responded. The TED folks just responded to say that they are shipping out a replacement display today and I should have it on Tuesday. Sweet!
Keep those fingers crossed.
UPDATE: I added a comment to my 'support ticket' and they just responded. The TED folks just responded to say that they are shipping out a replacement display today and I should have it on Tuesday. Sweet!
Thursday, August 11, 2011
My TED, Eragy
Howdy folks!
Well with the departure of Google PowerMeter the folks at The Energy Detective (TED) have come through and upgraded their equipment firmware to allow for other Energy Monitoring websites to be used. I've decided to try out MyEragy.com which is based out of Durham, NC. The Screenshot of the 'dashboard' is below:
It's not too bad. The actual TED dashboard is easier to use, but maybe this site will eventually allow me to link my daily usage to my Blog so I'll update it more often (yes...I've been slacking).
On top of that my TED5000 display stand has stopped charging my display unit. Dang! I've contact the folks at TED since I'm still under warranty. I just submitted my information so I should hear shortly. One thing that sucks is that they required me to show a copy of my receipt. Seriously? A receipt? It's been 7 months. The only reason I have the receipt is because it was in my 2010 taxes folder (yes...an energy monitor qualifies for the energy tax credit). Anyhow...if you get one of these, don't throw out the receipt. Maybe some day, they'll have a product registration option to their website so when you get the software, you register your device so you don't need to hold onto the receipt for a year.
UPDATE (8/17/11): As soon as I sent in the information, I got a RMA # and a FedEx return label same day. Fantastic work from these folks! Plus, I like not having to pay shipping. I FedExed my display back and I'm awaiting its return. I will say not having the display in the kitchen makes me feel...well...a little lost and uniformed.
Oh yeah....almost forgot...while at the Water Environment Federation (WEF) Energy and Water Conference last week, I saw a presentation that included energy monitors. The project was actual about using these monitors to measure energy usage from decentralized wastewater treatment systems (aka septic tank-type systems). Well...one interesting fact was that on average, folks who have an energy monitor use 10-15% less energy than those who do not....mainly because of just being informed.
So that's something to think about for anyone out there who's interested...
Well with the departure of Google PowerMeter the folks at The Energy Detective (TED) have come through and upgraded their equipment firmware to allow for other Energy Monitoring websites to be used. I've decided to try out MyEragy.com which is based out of Durham, NC. The Screenshot of the 'dashboard' is below:
It's not too bad. The actual TED dashboard is easier to use, but maybe this site will eventually allow me to link my daily usage to my Blog so I'll update it more often (yes...I've been slacking).
On top of that my TED5000 display stand has stopped charging my display unit. Dang! I've contact the folks at TED since I'm still under warranty. I just submitted my information so I should hear shortly. One thing that sucks is that they required me to show a copy of my receipt. Seriously? A receipt? It's been 7 months. The only reason I have the receipt is because it was in my 2010 taxes folder (yes...an energy monitor qualifies for the energy tax credit). Anyhow...if you get one of these, don't throw out the receipt. Maybe some day, they'll have a product registration option to their website so when you get the software, you register your device so you don't need to hold onto the receipt for a year.
UPDATE (8/17/11): As soon as I sent in the information, I got a RMA # and a FedEx return label same day. Fantastic work from these folks! Plus, I like not having to pay shipping. I FedExed my display back and I'm awaiting its return. I will say not having the display in the kitchen makes me feel...well...a little lost and uniformed.
Oh yeah....almost forgot...while at the Water Environment Federation (WEF) Energy and Water Conference last week, I saw a presentation that included energy monitors. The project was actual about using these monitors to measure energy usage from decentralized wastewater treatment systems (aka septic tank-type systems). Well...one interesting fact was that on average, folks who have an energy monitor use 10-15% less energy than those who do not....mainly because of just being informed.
So that's something to think about for anyone out there who's interested...
Saturday, August 6, 2011
August Energy Bill in...
I've never been so excited to get a bill in. Our Duke Energy bill showed up this afternoon while I was mowing the lawn. When I wife let me know I immediately asked, "How much?!?!" When she mumbled something to the range of 2600 kWh, I replied, "No F*$&#ing way!" That's when I went inside to find she was way off. Note...she did admit that she has no idea where that number came from since there isn't any 2600 or 2xxx number on the bill.
Anyhow...the totals (drum roll please...):
Total kWh = 888
Days = 28
Avg = 31.71 kWh/d
Aug 2010 Avg = 51.13 kWh/d (over 32 days)
2011 Savings = 37.97% Boooyahhhh!!!
Cost for July/August (trying to get an equivalent # of days):
2010 (54 days) = 2586 kWh = 47.89 kWh/d -->$246
2011 (61 days) = 1974 kWh = 32.36 kWh/d -->$190
Savings = 612 kWh -->$56 ....and that's using 7 days more electricity!
OK...compared to our 2005 built townhome:
2009 Total Energy Usage: 34.24 kWh/d
2011 Total Energy Usage: 31.71 kWh/d
Difference (2011 vs 2009): 92.6%
So again our work has paid off! Our 2700sf home built in 1986 used 7.4% less energy than our 1300sf townhome built in 2005.
That's just awesome! Again the savings would be greater if I wasn't running the dehumidifier so much. But, how can I complain???
I will note that my TED unit estimated 1071 kWh were used for the month. My first thoughts was that its a fairly big error although we were 3 days short (28 vs 31 days). 3 days @ 31.71 kWh/d = 95.13 kWh+888 = 983.13 kWh. 983.13/888 = 10.7% error. I guess you can't complain about a 10% error for a residential product.
Anyhow...the totals (drum roll please...):
Total kWh = 888
Days = 28
Avg = 31.71 kWh/d
Aug 2010 Avg = 51.13 kWh/d (over 32 days)
2011 Savings = 37.97% Boooyahhhh!!!
Cost for July/August (trying to get an equivalent # of days):
2010 (54 days) = 2586 kWh = 47.89 kWh/d -->$246
2011 (61 days) = 1974 kWh = 32.36 kWh/d -->$190
Savings = 612 kWh -->$56 ....and that's using 7 days more electricity!
OK...compared to our 2005 built townhome:
2009 Total Energy Usage: 34.24 kWh/d
2011 Total Energy Usage: 31.71 kWh/d
Difference (2011 vs 2009): 92.6%
So again our work has paid off! Our 2700sf home built in 1986 used 7.4% less energy than our 1300sf townhome built in 2005.
That's just awesome! Again the savings would be greater if I wasn't running the dehumidifier so much. But, how can I complain???
I will note that my TED unit estimated 1071 kWh were used for the month. My first thoughts was that its a fairly big error although we were 3 days short (28 vs 31 days). 3 days @ 31.71 kWh/d = 95.13 kWh+888 = 983.13 kWh. 983.13/888 = 10.7% error. I guess you can't complain about a 10% error for a residential product.
Monday, July 25, 2011
Reblog...
Hey folks-
I accidentially came across this blog and found it really interesting:
Tank or No Tank...Endless debate over hot water heating can stand to be cooled down
http://amicusgreen.typepad.com/amicus-answers/2010/03/tank-or-no-tankendless-debate-over-hot-water-heating-can-stand-to-be-cooled-down.html
It's old but very interesting. I am not considering a tankless hot water heater since its not really compatible with the geothermal desuperheater...but could be useful to other folks out there.
I accidentially came across this blog and found it really interesting:
Tank or No Tank...Endless debate over hot water heating can stand to be cooled down
http://amicusgreen.typepad.com/amicus-answers/2010/03/tank-or-no-tankendless-debate-over-hot-water-heating-can-stand-to-be-cooled-down.html
It's old but very interesting. I am not considering a tankless hot water heater since its not really compatible with the geothermal desuperheater...but could be useful to other folks out there.
Tuesday, July 19, 2011
June/July Energy Usage
Last month's energy usage numbers are in (ok...they've been in for awhile and I've forgotten...you busted me) and the results show more good news:
June/July 2010 Usage: 950 kWh / 22 days = 43.18 kWh/d
June/July 2011 Usage: 1,086 kWh/33 days = 32.91 kWh/d
Savings = 23.79%
Pretty good. One thing to note is last month/this month I've been running that dehumidifier a lot (see previous posts) so that usage is abnormally high.
Compared to the "old" townhome, my usage looks like:
June/July 2009 Usage: 794 kWh/33 days = 24.06 kWh + 8 CCF gas (7.5 kWh/d) = 31.61 kWh/d
Difference = 104.1%
So I was 4% higher...but then again, remove the dehumidifier usage and I'd be lower. But even at 4% higher...can I complain? 2005 built vs 1984 built. 1300 sf vs 2600 sf. Yeah...no way!
The July/August bills will be interesting given how hot its been lately (90s). Last year we used 1636 kWh (51.1 kWh/d). With the mid-high 90s now, we've only used a maximum of 40 kWh/d (last Friday when it was 99-100F). This years July/August bill will hold an additional 2-3 weeks of dehumidifier usage too. FYI, I've switched to 3 hrs on/3 hrs off operation. The system is off right now and the humidity is at 50%. Good. So maybe I'll let it run through the week to see where it ends up holding when its off.
June/July 2010 Usage: 950 kWh / 22 days = 43.18 kWh/d
June/July 2011 Usage: 1,086 kWh/33 days = 32.91 kWh/d
Savings = 23.79%
Pretty good. One thing to note is last month/this month I've been running that dehumidifier a lot (see previous posts) so that usage is abnormally high.
Compared to the "old" townhome, my usage looks like:
June/July 2009 Usage: 794 kWh/33 days = 24.06 kWh + 8 CCF gas (7.5 kWh/d) = 31.61 kWh/d
Difference = 104.1%
So I was 4% higher...but then again, remove the dehumidifier usage and I'd be lower. But even at 4% higher...can I complain? 2005 built vs 1984 built. 1300 sf vs 2600 sf. Yeah...no way!
The July/August bills will be interesting given how hot its been lately (90s). Last year we used 1636 kWh (51.1 kWh/d). With the mid-high 90s now, we've only used a maximum of 40 kWh/d (last Friday when it was 99-100F). This years July/August bill will hold an additional 2-3 weeks of dehumidifier usage too. FYI, I've switched to 3 hrs on/3 hrs off operation. The system is off right now and the humidity is at 50%. Good. So maybe I'll let it run through the week to see where it ends up holding when its off.
Sunday, July 17, 2011
It's been a while...
Sorry folks...I know its been a while. It's been wicked busy in the ole' household. But I'm back! The sad news is that Google PowerMeter is no more (see email received below):
Dear PowerMeter User,
We first launched Google PowerMeter as a Google.org project to raise awareness about the importance of giving people access to their energy information. Since our launch, there's been more attention brought to this issue, and we're excited that PowerMeter has helped demonstrate the importance of access to energy data. However, our efforts have not scaled as quickly as we would have liked, so we have decided to retire PowerMeter.
You will continue to have access to the product until September 16, 2011, after which time you will no longer be able to access your PowerMeter account. We know that having access to your energy information has helped you save energy and money. There are many options available for you from our device and utility partners. Please visit this page to learn more:http://www.google.com/support/
We also understand that having your historical energy data is important to you. We've made it easy for you to download your data. To export your PowerMeter data to a CSV (Comma Separated Values) file, log in to your account and go to "Account Settings." More information can be found here: http://www.google.com/support/
We appreciate your understanding and hope that you've enjoyed using Google PowerMeter. If you have questions about this announcement, please visit our FAQ pages athttp://www.google.com/
Thank you,
Google PowerMeter team
© 2011 Google Inc. 1600 Amphitheatre Parkway, Mountain View, CA 94043
You've received this mandatory service announcement email to update you about important changes to your Google PowerMeter account.
Granted, this really has no effect on me. My TED will record data just fine and I'll still be able to blog about it. It's just I was hoping to show y'all my PowerMeter on my blog. I guess I can ditch that effort now. Maybe I'll have to investigate how to replicate my TED data somewhere else. Or at least have an automatic posting of what my daily usage is. That would be neat. Of course, that means I need to learn some potentially complicated coding. Bah! But...that's what my family of computer knowledgeable people is for, right? And my computer knowledgeable friends too.
FYI...I plan to get back on the ole' blog bandwagon a little more in the upcoming weeks. I have a ton of pics from some of my early energy efficiency work before I had this blog...or TED for that matter.
Oh yeah....update on the dehumidifier. It's still going on/off. That's annoying. But with the recent thunderstorms that has knocked out power (the dehumidifier doesn't automatically start back up), I've seen that the crawl space is now at 62% and holding. In a previous post a couple weeks back, after another power outage it was 67%, so its lowering. I just need to get it down to below 60% (maybe 55%?) and I'll be happy. It's probably sucking up all the water in the wood from the many previous years of high humidity. I may just setup the dehumidifier to run 3 hrs on/3 hrs off and I'll monitor how low it gets the crawl space to...and then how the humidity returns to. I gotta think that the lower the crawl space gets in the 3 hrs on...the more 'mass transfer' of water there will be from the wood to the atmosphere which will be removed. So the greater the 'delta' between air and wood, the faster the transfer. And that'll help me get to below my humidity goal.
Ok...that's enough...until next time...
Dear PowerMeter User,
We first launched Google PowerMeter as a Google.org project to raise awareness about the importance of giving people access to their energy information. Since our launch, there's been more attention brought to this issue, and we're excited that PowerMeter has helped demonstrate the importance of access to energy data. However, our efforts have not scaled as quickly as we would have liked, so we have decided to retire PowerMeter.
You will continue to have access to the product until September 16, 2011, after which time you will no longer be able to access your PowerMeter account. We know that having access to your energy information has helped you save energy and money. There are many options available for you from our device and utility partners. Please visit this page to learn more:http://www.google.com/support/
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You've received this mandatory service announcement email to update you about important changes to your Google PowerMeter account.
Granted, this really has no effect on me. My TED will record data just fine and I'll still be able to blog about it. It's just I was hoping to show y'all my PowerMeter on my blog. I guess I can ditch that effort now. Maybe I'll have to investigate how to replicate my TED data somewhere else. Or at least have an automatic posting of what my daily usage is. That would be neat. Of course, that means I need to learn some potentially complicated coding. Bah! But...that's what my family of computer knowledgeable people is for, right? And my computer knowledgeable friends too.
FYI...I plan to get back on the ole' blog bandwagon a little more in the upcoming weeks. I have a ton of pics from some of my early energy efficiency work before I had this blog...or TED for that matter.
Oh yeah....update on the dehumidifier. It's still going on/off. That's annoying. But with the recent thunderstorms that has knocked out power (the dehumidifier doesn't automatically start back up), I've seen that the crawl space is now at 62% and holding. In a previous post a couple weeks back, after another power outage it was 67%, so its lowering. I just need to get it down to below 60% (maybe 55%?) and I'll be happy. It's probably sucking up all the water in the wood from the many previous years of high humidity. I may just setup the dehumidifier to run 3 hrs on/3 hrs off and I'll monitor how low it gets the crawl space to...and then how the humidity returns to. I gotta think that the lower the crawl space gets in the 3 hrs on...the more 'mass transfer' of water there will be from the wood to the atmosphere which will be removed. So the greater the 'delta' between air and wood, the faster the transfer. And that'll help me get to below my humidity goal.
Ok...that's enough...until next time...
Friday, July 1, 2011
More dehumidifier stuff
OK...so I ran the dehumidifer with the fan on for about 2 weeks. Mind you...the dehumidifier itself should turn the air over in the crawl space at least 24 times per day...in a perfect world. So with the fan running it should do a better job. Well, it ran constantly for a long time and when the dehumidifer started cycling, I knew I must be close.
So yesterday, I turned off the fan and just let the dehumidifer do its thing. Unfortunately, I didn't read the manual and thought that setting it on the "3 hrs" mode would mean it would run for 3 hours then turn off. Nope...it means its runs for 3 hrs...then turns off...and then 3 hrs later it turns on. Seriously? It has a 6, and 12 version of the same thing. Really? So there's no way to save on electricity? It's 12 hrs of operation or Auto?!?
Come on!
OK...so this morning I switched it back to "Auto" mode...and from the figure below you can see that its constantly cycling again. Dang it!
![]()
My guess is that I'm going to have to purchase a cheap-o $15 box fan and install it down in the crawl space with it hooked up to one of those "smart strips". Such that when the dehumidifer turns on...then it turns on the box fan also. Maybe that'll fix this annoying constant "on/off" cycling. It's OK, if it turns on once every hour...but ever couple minutes sucks!
BTW, my power usage jumped up to about 45 kWH/day (OUCH!) with the fan and the dehumidifer running non-stop. Once I turned off the fan, it went down to 36 kWh/day. My goal is to get it back to 30 kWh/day if I can ever get the dang dehumidifer to stop running for 8 hrs!
So yesterday, I turned off the fan and just let the dehumidifer do its thing. Unfortunately, I didn't read the manual and thought that setting it on the "3 hrs" mode would mean it would run for 3 hours then turn off. Nope...it means its runs for 3 hrs...then turns off...and then 3 hrs later it turns on. Seriously? It has a 6, and 12 version of the same thing. Really? So there's no way to save on electricity? It's 12 hrs of operation or Auto?!?
Come on!
OK...so this morning I switched it back to "Auto" mode...and from the figure below you can see that its constantly cycling again. Dang it!
My guess is that I'm going to have to purchase a cheap-o $15 box fan and install it down in the crawl space with it hooked up to one of those "smart strips". Such that when the dehumidifer turns on...then it turns on the box fan also. Maybe that'll fix this annoying constant "on/off" cycling. It's OK, if it turns on once every hour...but ever couple minutes sucks!
BTW, my power usage jumped up to about 45 kWH/day (OUCH!) with the fan and the dehumidifer running non-stop. Once I turned off the fan, it went down to 36 kWh/day. My goal is to get it back to 30 kWh/day if I can ever get the dang dehumidifer to stop running for 8 hrs!
Monday, June 20, 2011
Dehumidifer
OK...so in my last post i talked about how I turned my vented crawl space to an unvented crawl space. Overall, it isn't doing too bad. Humidity is around 50% inside the house, while I have the crawl space dehumidifer set to 60%...although the wireless sensor I have in there says its around 55%. Whatever...
Well...one thing has been bothering me, which is the amount of time, the dehumidifier runs. Where the heck is the wet air coming from? See the pic from TED below:
![]()
This is minute data...and you can see the small bumps in power usage. Looking further, it appears the dehumidifer is turning on roughly 6-7x/hour. When it runs...it runs for roughly 2-3 minutes. Doing the math...24 hrs/day x 7ops/hr x 3 min/ops = 504 minutes per day of operation. 504 minutes = 8.4 hrs. Why is this thing running for 8.4 hours?
I went down into the crawl space and checked the door...and its sealed pretty tightly. I checked all the vents and all were well sealed...except 2, which I added more caulking to yesterday. But...no substantial change in operation. I also checked the plastic and didn't find anything.
Here's my theories:
1) There's some holes at the end of the crawl space that appear to be ports to look at the steel beams under my garage workshop. Some moisture could be coming from there...
2) Some moisture is coming from the house. However...I'm holding 50-55% RH inside the house according to the inside thermostats...so it shouldn't be running unless the RH inside the house gets higher. This could be a factor...but I doubt its contributing.
3) The crawl space is not 100% sealed. I'm sure there's some, but I would think that there isn't enough humidity entering to account for 2.8 pints/day (That's 50 pints/day capacity of the dehumidifier x 24/8.4).
4) The dehumidifer humidistat is too sensitive/not all that great. This wouldn't surprise me one bit...especially since I have the unit set to maintain 60% RH and the wireless sensor nearby is showing 55% RH. I could setup the dehumidifer to only operate for X hrs/day (I think its limited to 3, 6, 8, or 12 hrs.) I may try that to see how it works. I'll try it low...like 3 hrs to see how well it does. Generally, humidity is highest in the morning...so I'll have it run then.
So...overall, I think I'll buy some spray in foam to close those holes/ports at the end of the crawl space. Then I'll setup the demudifier to only operate for a set amount of time. And then I'll monitor some more.
Well...one thing has been bothering me, which is the amount of time, the dehumidifier runs. Where the heck is the wet air coming from? See the pic from TED below:
I went down into the crawl space and checked the door...and its sealed pretty tightly. I checked all the vents and all were well sealed...except 2, which I added more caulking to yesterday. But...no substantial change in operation. I also checked the plastic and didn't find anything.
Here's my theories:
1) There's some holes at the end of the crawl space that appear to be ports to look at the steel beams under my garage workshop. Some moisture could be coming from there...
2) Some moisture is coming from the house. However...I'm holding 50-55% RH inside the house according to the inside thermostats...so it shouldn't be running unless the RH inside the house gets higher. This could be a factor...but I doubt its contributing.
3) The crawl space is not 100% sealed. I'm sure there's some, but I would think that there isn't enough humidity entering to account for 2.8 pints/day (That's 50 pints/day capacity of the dehumidifier x 24/8.4).
4) The dehumidifer humidistat is too sensitive/not all that great. This wouldn't surprise me one bit...especially since I have the unit set to maintain 60% RH and the wireless sensor nearby is showing 55% RH. I could setup the dehumidifer to only operate for X hrs/day (I think its limited to 3, 6, 8, or 12 hrs.) I may try that to see how it works. I'll try it low...like 3 hrs to see how well it does. Generally, humidity is highest in the morning...so I'll have it run then.
So...overall, I think I'll buy some spray in foam to close those holes/ports at the end of the crawl space. Then I'll setup the demudifier to only operate for a set amount of time. And then I'll monitor some more.
Monday, June 6, 2011
Initial Energy Savings! 30-40%!
Probably for the first time....I was super excited to get my Duke Energy bill. This is one of the first bills to really show all my energy efficiency work. What was the results?
Last month I used 526 kWh. That's lowest we've had since moving in and equals 17.53 kWh/d. That's even lower than the previous month (593 kWh) when we didn't use the HVAC at all.
How are we doing compared to last year?
March 2010 vs 2011: 34% less <---some heating until late in the month
April 2010 vs 2011: 4% less <---didn't use HVAC at all
May 2010 vs 2011: 41% less <---cooling started late in the month
Just awesome! I'm thrilled...it's showing all that work is cashing in.
I also decided to compare my energy usage between this home (built 1986, 2700 sf) versus our old townhome (built 2005, 1300 sf). Note for the "old" townhome I had to convert natural gas usage to electricity equivalent because both hot water heater and cooking used natural gas. It's an easy conversion...if you want to know...ask. OK here's the total energy consumption between the two places:
Feb 2011 vs Feb 2009: 26% less
Mar 2011 vs Mar 2009: 39% less
Apr 2011 vs Apr 2009: 22% less
May 2011 vs May 2009: 26% less
How awesome is that? Our older, larger home is more energy efficiency than the newer, smaller, townhome. Frickin' awesome. I'm excited to see what the next bill shows...until July!!!
Last month I used 526 kWh. That's lowest we've had since moving in and equals 17.53 kWh/d. That's even lower than the previous month (593 kWh) when we didn't use the HVAC at all.
How are we doing compared to last year?
March 2010 vs 2011: 34% less <---some heating until late in the month
April 2010 vs 2011: 4% less <---didn't use HVAC at all
May 2010 vs 2011: 41% less <---cooling started late in the month
Just awesome! I'm thrilled...it's showing all that work is cashing in.
I also decided to compare my energy usage between this home (built 1986, 2700 sf) versus our old townhome (built 2005, 1300 sf). Note for the "old" townhome I had to convert natural gas usage to electricity equivalent because both hot water heater and cooking used natural gas. It's an easy conversion...if you want to know...ask. OK here's the total energy consumption between the two places:
Feb 2011 vs Feb 2009: 26% less
Mar 2011 vs Mar 2009: 39% less
Apr 2011 vs Apr 2009: 22% less
May 2011 vs May 2009: 26% less
How awesome is that? Our older, larger home is more energy efficiency than the newer, smaller, townhome. Frickin' awesome. I'm excited to see what the next bill shows...until July!!!
Pic of finished crawl space
Here's a pic of the finished crawl space. Nice, huh? I put down unused shingles at the entrance and around the hvac equipment to minimize damage during routine maintenance.
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Crawl Space Conditioning
Wow...it's been a while since I last posted. But, things have been slow...until recently when I discovered lots of moisure in my crawl space. Some background:
In the hot and humid south, moisture control is important in the crawl space to insure you don't allow mold to grow or provide ideal conditions for insects which can damage the underfloor joists for the house. Old technology to control moisture was to put plastic on the ground (aka a vapor barrier) which would stop water for coming out of the soil. It would also include putting in vents to "ventilate" the crawl spaces thereby removing moisture. However...recent studies (Example: http://www.smartvent.net/docs/crawlspacestudy.pdf or http://www.rlcengineering.com/csfallacies.htm) have shown that while some moisture is from the earth...the majority of it generally comes from the humidity in the air. Note that folks are making a living off of fixing crawl spaces...for example: http://www.dryprosystems.com/crawl-space-repair/vapor-barrier.html
Well...so far this summer has seen some very hot and humid days. In the past week temperatures have been in the lower-mid 90s with the humidity between 65 and 87%. Well...when those hot temperatures and the high humidity, when the air enters the crawl space, it can reach the dew point and begin codensation. That's what I found in my crawl space. I had been monitoring my crawl space using a wireless weather station with the transmitter located in the crawl space. I thought it was fantastic that my crawl space had 20% humidity until I started getting suspicous during the past couple weeks 80+% humidity days. So I checked the meter and the humidstat was broken. I bought another weather station (Walmart - $15) and saw the truth...my crawl space had humidities in the 70-80% range. That's bad. And when I checked out the crawl space for mold, I didn't see any (good...probably because last year I went around and used a moldicide when I found some during a energy audit). But I did find condenation all over what was left of my old vapor barrier (which was in various pieces...torn a lot...barely covering the sand floor).
I had gotten an estimate in the past to encapsulate the crawl space and wow was it expensive: $2800 for a 20Mil liner plus dehumidifer. And over $7,000 for the full encapsulation which includes spray foam insulation on the crawl space walls.
In the hot and humid south, moisture control is important in the crawl space to insure you don't allow mold to grow or provide ideal conditions for insects which can damage the underfloor joists for the house. Old technology to control moisture was to put plastic on the ground (aka a vapor barrier) which would stop water for coming out of the soil. It would also include putting in vents to "ventilate" the crawl spaces thereby removing moisture. However...recent studies (Example: http://www.smartvent.net/docs/crawlspacestudy.pdf or http://www.rlcengineering.com/csfallacies.htm) have shown that while some moisture is from the earth...the majority of it generally comes from the humidity in the air. Note that folks are making a living off of fixing crawl spaces...for example: http://www.dryprosystems.com/crawl-space-repair/vapor-barrier.html
Well...so far this summer has seen some very hot and humid days. In the past week temperatures have been in the lower-mid 90s with the humidity between 65 and 87%. Well...when those hot temperatures and the high humidity, when the air enters the crawl space, it can reach the dew point and begin codensation. That's what I found in my crawl space. I had been monitoring my crawl space using a wireless weather station with the transmitter located in the crawl space. I thought it was fantastic that my crawl space had 20% humidity until I started getting suspicous during the past couple weeks 80+% humidity days. So I checked the meter and the humidstat was broken. I bought another weather station (Walmart - $15) and saw the truth...my crawl space had humidities in the 70-80% range. That's bad. And when I checked out the crawl space for mold, I didn't see any (good...probably because last year I went around and used a moldicide when I found some during a energy audit). But I did find condenation all over what was left of my old vapor barrier (which was in various pieces...torn a lot...barely covering the sand floor).
I had gotten an estimate in the past to encapsulate the crawl space and wow was it expensive: $2800 for a 20Mil liner plus dehumidifer. And over $7,000 for the full encapsulation which includes spray foam insulation on the crawl space walls.
Screw that...I'm doing it myself. Here's the method I used: http://www.dom.com/about/conservation/pdf/crawlspaces.pdf (Unvented crawl space). Note: my crawl space is about 1300 sf and varies from about 4.5-ft in height to about 3 in height. Not too bad. Here's a very old pic when we moved in that shows the hot water heater (which now has insulation on it and all the hot water pipes have insulation as well):
See how it looks like crap in there?
So, on Saturday @ 6am, I began 15 hours of fun in the crawl space. I pulled out the old liner and any other junk that was in there. I closed off all the vents and sealed them up. Then I began putting up a 6mil liner with construction adhesive and super-all-weather gorilla tape. Why a 6Mil liner vs the 20Mil liner above? Well...first...a 20mil liner is like a frickin' pool liner. The stuff is tonka. Well, 6mil is more than strong enough since I don't store anything in my crawl space so why do I need something super heavy duty? Anyhow, after putting down the liner I then sealed up the attic door (built a frame and put on weatherstripping).
Overall, it turned out great (I'll post some pics later). The crawl space does not smell moldy/musty anymore. The dehumidifer did a great job lowering the humidity from 78% to 48%. I got worried for a while because my power usage shot up (I think the unit uses around 700W? And yesterday I used 44 kWh..yikes!) and stayed up for about 2 days, but its now caught up and turned off with the humidity is holding steady.
Now I have to recovery from my sore back and legs from working down there for so long...
Monday, May 23, 2011
Energy Usage without the HTPC
Ok...so my HTPC "broke" last week and has been offline. While I've been trying to troubleshoot the issues (I think I determined its the power supply), I've been able to look really how much energy it consumes. Below is a figure from Google Powermeter which shows my energy usage before and after the HTPC is shutdown. I would ignore Saturday and Sunday because there was a power failure at the house which messed up the readings.
Note the "always on" power usage drops from about 8 kWh to 5 kWh. This represents 3 kWh of savings or 125W. That's some signficant savings! (FYI: Kudos to my wife who also significantly reduced power usage while I was away on business. I will mention that this is because she spent the majority of her time at her sister's place. So minimal cooking, no TV, etc.)
Note the "always on" power usage drops from about 8 kWh to 5 kWh. This represents 3 kWh of savings or 125W. That's some signficant savings! (FYI: Kudos to my wife who also significantly reduced power usage while I was away on business. I will mention that this is because she spent the majority of her time at her sister's place. So minimal cooking, no TV, etc.)
So, I'd say that there's a lot of room to fix this. As I've said in the past, updating my HTPC will significantly help power usage. Reducing the power consumption down to 40W (which many reviews have shown modern PCs can do) could reduce HTPC power consumption by 68% reducing "always on" power consumption from 8 kWh to 6 kWh (HTPC would consume 0.96 kWh/d). Yeah, I know someone will mention the two extremes: "Why don't you not use the HTPC at all and save that energy?!?" or "Who cares? That only saves you $0.1734/d or $5.27/month". For the first question...(1) This is my hobby and I'll take the penalty. And for (2), you're right it isn't a lot...but it's the thought that counts, right? Plus it feeds the hobby mention in (1). Oh...and don't forget I've already cut out a lot of the big things to do...so now I'm down to the small stuff anyway.
Monday, May 2, 2011
Misc Home Improvements
This weekend, I dug into the Duke Energy "Energy Efficiency Kit" that I was given. I changed out some light bulbs which I hadn't done previously. Unfortunately, the CFLs in my MBR ceiling fan flicker at night, so I'm guessing those might need to be changed back...or maybe I'll just install one bulb instead of two.
I also replaced my shower head with the new 1.5 gpm shower head. It works great! Not to mention my old one didn't have the rubber flow restricter installed so it was at least putting out 2.5-3 gpm previously. This should not only save water, but more importantly, reduce the hot water usage and regen required.
I also setup my downstairs (den) HTPC frontend to go to "sleep" when i shut it off. That saves me about 32W of 24/7 power reducing it from 40W to 8W. It's not zero, but still a nice reduction.
Next up...I'll be upgrading the main HTPC (which uses about 100W @ idle). To do this, I need to pretty much need to rebuild the main components (cpu/mobo/memory). Rumor has it the AMD "bulldozer" will be optimal when it comes out in June/July. And that is supposed to idle around 10-20W which is a healthy reduction in power usage.
I also replaced my shower head with the new 1.5 gpm shower head. It works great! Not to mention my old one didn't have the rubber flow restricter installed so it was at least putting out 2.5-3 gpm previously. This should not only save water, but more importantly, reduce the hot water usage and regen required.
I also setup my downstairs (den) HTPC frontend to go to "sleep" when i shut it off. That saves me about 32W of 24/7 power reducing it from 40W to 8W. It's not zero, but still a nice reduction.
Next up...I'll be upgrading the main HTPC (which uses about 100W @ idle). To do this, I need to pretty much need to rebuild the main components (cpu/mobo/memory). Rumor has it the AMD "bulldozer" will be optimal when it comes out in June/July. And that is supposed to idle around 10-20W which is a healthy reduction in power usage.
Tuesday, April 26, 2011
Time of Use Rates
So I'm currently investigating moving my electricity rate structure from my current (RE) which is pretty much set at $0.086/kWh ( http://www.duke-energy.com/pdfs/NCScheduleRE.pdf ) to a time of use rate structure ( http://www.duke-energy.com/pdfs/NCScheduleRT.pdf ). Yeah, there is a small tier when you use over 350 kWh where it goes down to 0.078 in the summer...but that isn't significant. Well, thanks to my TED 5000, I analyzed my historial data to see if it was worthwhile.
First the rates...the time of use rates (TOU) as shown below have a higher facility charge and lower overall rates. However, there's this "On-peak demand" charge. Well, that charge is defined as "the maximum integrated thirty-minute demand measured for the On-Peak period during the month". So that means if I use 10 kW for 30 minutes in the Winter, then I'll get: 10 KW x $3.33 = $33.30 demand charge. Sounds expensive right? Well, let's see if it really works out...
Below is the my historical hourly energy usage from January 18, 2011 to April 18, 2011.
As you can see, in the winter I had some pretty high 1-hr usages (Note: I did 1 hr usage to get more historical data - 90 days - vs the minute data which would have only stretched 48 hrs).
But how does this fall during peak times? See the graph below which segregates out only the data during peak times:
Generally speaking, the vast majority of the elecrical usage is below 2 KW. But...there were some pretty noticable peaks. The extremely large peaks (8-16 KWH) were from that old crappy heat pump using the emergency heat (i.e. electric) because it couldn't keep up. Those in the 4-6 kWH range are most likely either the dryer or the hot water being generated. Those between 2-4 KWH could be a bunch of things...and most likely it was one heat pump on (~3.5 KW). Not to mention this is a 1-hr average.
So...if I take this hourly data and apply the on and off peak rates, then determine the max 1-hr power usage and apply the on-peak demand charge, what does that get me? See the table below:
The "Ex Cost" column is the TED estimated cost for the month. Overall, it's pretty close. "Peak TOU" and "Off TOU" are the costs at the "on-peak" and "off-peak" rates. Then I add in the Facility charge (a constant montly value). Finally, I determine the Max 1-hr demand and multiply it by the winter charge ($3.33/KW). Note that April-11 is currently an anomaly because its less than 1/2 the month so the facility+on-demand charge make up 1/2 the cost.
Overall, it shows that I could have saves ~$32 over 4 months with the TOU rates. It doesn't seem like a lot right? Well, one thing to remember is that I wasn't even trying to curb my electricity usage. When I look back at the raw data...the vast majority of the peak usages occured between 7 - 8am (see below):
Well...that's due to how I have my programmable thermostate setup and when we take showers for work. If we get the house heated up 1 hrs earlier and we finish our showers 30 min earlier those peaks are off-demand. Now there still is some demand (see below), but its significantly less. Not to mention I now have a significantly higher efficiency HVAC system. So I would expect these peaks to be much lower. The worst load would be when the hot water heater runs (4.8 KWH) and that typically lasts only about 10-15 minutes.
So overall...if we can keep our peak demand to below, say 4 KW, during those peak times (that would be both the upstairs and downstairs geothermal systems running for 30 minutes), then I could increase those historical savings from $32 to $107.
Moving forward...I think with all the energy effiicency stuff I've done (insulation, geothermal, etc), I think I can reap some great benefits. During the summer, the hot water running won't be an issue thanks to the desuperheater. It'll just be the A/C...which I can mitigate by setting the thermostat high during that short period of time. Plus, I'll probably only have the upstairs system run and will have the downstairs system essentially off.
It'll be interesting to try out...I'll try to post something up after this summer to show the results...
First the rates...the time of use rates (TOU) as shown below have a higher facility charge and lower overall rates. However, there's this "On-peak demand" charge. Well, that charge is defined as "the maximum integrated thirty-minute demand measured for the On-Peak period during the month". So that means if I use 10 kW for 30 minutes in the Winter, then I'll get: 10 KW x $3.33 = $33.30 demand charge. Sounds expensive right? Well, let's see if it really works out...
Below is the my historical hourly energy usage from January 18, 2011 to April 18, 2011.
But how does this fall during peak times? See the graph below which segregates out only the data during peak times:
So...if I take this hourly data and apply the on and off peak rates, then determine the max 1-hr power usage and apply the on-peak demand charge, what does that get me? See the table below:
| Ex Cost | Peak TOU | Off TOU | TOU Total | Fac Charge | Max 1 hr KWH | OnPeak Chrg | Total | |
| Jan-11 | $153.36 | $12.75 | $67.23 | $79.98 | $13.88 | 15.49 | $51.59 | $145.45 |
| Feb-11 | $104.82 | $9.19 | $45.26 | $54.44 | $13.88 | 5.52 | $18.36 | $86.69 |
| Mar-11 | $99.41 | $9.15 | $42.04 | $51.19 | $13.88 | 6.55 | $21.82 | $86.89 |
| Apr-11 | $43.02 | $3.75 | $19.06 | $22.81 | $13.88 | 3.97 | $13.23 | $49.92 |
| Total | $400.61 | $34.83 | $173.58 | $208.42 | $55.52 | $368.95 | ||
| savings | $31.66 |
The "Ex Cost" column is the TED estimated cost for the month. Overall, it's pretty close. "Peak TOU" and "Off TOU" are the costs at the "on-peak" and "off-peak" rates. Then I add in the Facility charge (a constant montly value). Finally, I determine the Max 1-hr demand and multiply it by the winter charge ($3.33/KW). Note that April-11 is currently an anomaly because its less than 1/2 the month so the facility+on-demand charge make up 1/2 the cost.
Overall, it shows that I could have saves ~$32 over 4 months with the TOU rates. It doesn't seem like a lot right? Well, one thing to remember is that I wasn't even trying to curb my electricity usage. When I look back at the raw data...the vast majority of the peak usages occured between 7 - 8am (see below):
| Sum of Winter Peak Elec | ||
| hour | Total KWH | |
| 0.00 | 0.000 | |
| 1.00 | 0.000 | |
| 2.00 | 0.000 | |
| 3.00 | 0.000 | |
| 4.00 | 0.000 | |
| 5.00 | 0.000 | |
| 6.00 | 0.000 | |
| 7.00 | 238.660 | |
| 8.00 | 75.460 | |
| 9.00 | 61.612 | |
| 10.00 | 57.602 | |
| 11.00 | 62.269 | |
| 12.00 | 66.023 | |
| 13.00 | 0.000 | |
| 14.00 | 0.000 | |
| 15.00 | 0.000 | |
| 16.00 | 0.000 | |
| 17.00 | 0.000 | |
| 18.00 | 0.000 | |
| 19.00 | 0.000 | |
| 20.00 | 0.000 | |
| 21.00 | 0.000 | |
| 22.00 | 0.000 | |
| 23.00 | 0.000 |
Well...that's due to how I have my programmable thermostate setup and when we take showers for work. If we get the house heated up 1 hrs earlier and we finish our showers 30 min earlier those peaks are off-demand. Now there still is some demand (see below), but its significantly less. Not to mention I now have a significantly higher efficiency HVAC system. So I would expect these peaks to be much lower. The worst load would be when the hot water heater runs (4.8 KWH) and that typically lasts only about 10-15 minutes.
| Max of Winter Peak Elec | ||
| hour | max 1-hr KWH | |
| 0.00 | 0.000 | |
| 1.00 | 0.000 | |
| 2.00 | 0.000 | |
| 3.00 | 0.000 | |
| 4.00 | 0.000 | |
| 5.00 | 0.000 | |
| 6.00 | 0.000 | |
| 7.00 | 15.492 | |
| 8.00 | 3.785 | |
| 9.00 | 6.554 | |
| 10.00 | 3.214 | |
| 11.00 | 3.977 | |
| 12.00 | 5.078 | |
| 13.00 | 0.000 | |
| 14.00 | 0.000 | |
| 15.00 | 0.000 | |
| 16.00 | 0.000 | |
| 17.00 | 0.000 | |
| 18.00 | 0.000 | |
| 19.00 | 0.000 | |
| 20.00 | 0.000 | |
| 21.00 | 0.000 | |
| 22.00 | 0.000 | |
| 23.00 | 0.000 |
So overall...if we can keep our peak demand to below, say 4 KW, during those peak times (that would be both the upstairs and downstairs geothermal systems running for 30 minutes), then I could increase those historical savings from $32 to $107.
Moving forward...I think with all the energy effiicency stuff I've done (insulation, geothermal, etc), I think I can reap some great benefits. During the summer, the hot water running won't be an issue thanks to the desuperheater. It'll just be the A/C...which I can mitigate by setting the thermostat high during that short period of time. Plus, I'll probably only have the upstairs system run and will have the downstairs system essentially off.
It'll be interesting to try out...I'll try to post something up after this summer to show the results...
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