Duke Energy Home Energy Report 2014

In Decenber, my home used 25% less energy than an "Efficient" Home according to Duke Energy.  Damn right!

So yesterday I got a fancy document in the mail from Duke Energy that was my "home energy report" for the year.  I had to share since it indicated that my home is "among the most efficient in your areas and is the envy of your neighbors".  Well, duh...yeah!  As it shows in the pic above for December 2014 alone, my house was 25% more efficient than Duke's "Efficient Home". 

My Energy Usage over the last year.  I'm the yellow line way below the "average" home (blue) and the "efficient" home (green)

They also included a nice graph of my energy usage over the year compared to an "average" home and an "efficient home".  My house is WAYYY below the average home (50-60% less?) and is well below the "efficient home" (25-40% less?).  Maybe Duke needs to revise their definition of an "efficient home"! 

October Energy Bill. Up yet still Down

September  2013 Energy Usage

Wow...what a wondrous month its been.  The kiddos are certainly keeping me busy and slightly sleep deprived.  But it's getting better.  Every week they are sleeping a little more during the night.   As I mentioned last month, I knew my energy usage was going to sky-rocket.  But I think it's been manageable.  While overall, my energy usage for this month compared to last is up by 45% (see detailed info below), I was expecting much worse.  Let's show the Bill results first:

October 2012 (Sept 5 - Oct 2) --> Blog Post Here

Total Energy Consumption = 409 kWh
No. of Days = 28
Average Daily Energy Consumption = 14.61 kWh/day
Bill = $49.91


October 2013 (Sept 4 - Oct 2)

Total Energy Consumption = 595 kWh
No. of Days = 28
Average Daily Energy Consumption = 21.25 kWh/day (45.5% INCREASE in consumption)
Bill = $68.13

Looks bad right?  However, October 2012 was also one of my lowest energy usage months ever too.  Much of my usage was in the first half of the month (see the Pic above) where I was using about 30 kWh/day.  That was all HVAC usage as I needed to keep the house around 72F for the kiddos.  Halfway through the month I was able to turn the system off because the nighttime temperatures were cool enough to allow me to open up the windows at night and use "super fan" to cool the house.  

So I asked myself...how does it compare to October 2011?  The geothermal was still installed, just not the GE Geospring.  So here's that comparison:

October 2011 (associated blog post here)

Total Energy Consumption = 771 kWh
No. of Days = 32
Average Daily Energy Consumption = 24.09 kWh/day
Bill = $79.75

So 2013 was a 11.8% DECREASE in energy consumption compared to 2011.  Now, there's some savings.
So in about a week, I'm getting 1.962 kW of solar panels installed.  I chose to go this route since I believe I've done what I can practically on the energy efficiency side of my home.  All that work resulted in roughly a 50% decrease in my annual energy consumption (compared to 2010 when I moved in) .  Only after all of that work was done would I consider energy generation.

Overall, the solar panels should produce roughly 1/3 of my annual power usage.  I have a limited southern roof exposure so that was part of it of not trying to get more.  I could always add more panels in the future, but they would have to go on my West Facing roof.  Stay tuned next week for that blog posting.  I'll also include my math on ROI.

January 2013 Bill Results...Another Big Reduction

A pic of my dog enjoying his new Xmas chew toy.  Yes, those are my super awesome slippers.  They certainly help keep the cold floors away from my toes!

Hello folks-

The holidays have past and so has another year of energy savings.  My Duke Energy Bill was not quite like a Christmas gift (Hey Duke...a great gift would have been NO BILL...hint hint) with the results posted below:

January 2012 Bill
Power Usage:  1,318 kWh
No. of Days:  33
Average Daily Consumption:  39.94 kWh/day
Bill:  $121

January 2013 Bill (Dec 3 - Jan 3rd)
Power Usage:  940 kWh
No. of Days:  31
Average Daily Consumption:  30.32 kWh/day  (24.1% reduction from 2012)
Bill:   $95.84
Absolute Bill Savings:  $25.16
Rate Adjusted Savings ($0.102/kWh): $50.47

I gotta say...wow.  I never expected this...especially since last year we were fully into the Geothermal.  My power usage was the same as last month at 30.3 kWh/day...I'm consistent.  It does make me wonder...let's check the Heating Degree Days (HDD's) from NOAA:

Dec 3 - Jan 3 2012
No. of HDDs:  533

No. of Days:  33
Average Energy Usage:  39.94 kWh/day
Average kWh/HDD:  2.45 kWh/HDD

Dec 3 - January 2013
No. of HDDs:  538

No. of Days:  31 

Average Energy Usage:  30.32 kWh/d
Average kWh/HDD:  1.75 kWh/HDD (28.8% reduction from 2012)

So, there was just as many HDDs as last year...and actually its more given that there's 2 less days.  Yet I had less Energy consumption, so I guess some of my energy reduction projects are paying off.  Most likely the GE Geospring ASHP water heater is really helping given that its this time of year (Brrrr...cold) that a lot of hot water is being used.  But I'm sure some of my other projects are helping out too:

1)  HTPC Upgrade
2)  New Fridge
3)  Better Controlling Ecobee Thermostats  (My HVAC installer is now an authorized Ecobee Installer...He liked my setup so much he signed up!)

Below are some pics from my Ecobee Home IQ for the month:

Downstairs Ecobee Information

Upstairs Ecobee Information

I will say that this Ecobee information is pretty useless to me as is.  I'm got lots of questions for Ecobee.  Such as the stars...how can 1 part of my house be 1 star and the other be 3 stars?  Especially if both systems appear to run identical hours!  And I have the same house information for each thermostat!  And yes, my system runs 68% more than a typical system in my area (BTW...what is my area?)...it's a heat pump...it will always run longer than most conventional systems.  Not to mention it was sized correctly so it will always run longer (closer to optimum) which is its maximum efficiency.  Not to mention, if you're comparing my geothermal heat pump to a furnace, my system will always run longer.  My system doesn't blast out 120F air for 5 min then turn off.   If you notice my average house temp set point is 65F.  That's pretty awesome!  I could let it go less, but there's no reason to.  That's because my house never cools lower than this temp.  Check out the pic below from my Ecobee:

Upstairs HVAC runtime information via my Ecobee Thermostat

First off...let me say that the information above is what really makes the Ecobee spectacular. OK...if you look at the graph above you'll see that when my house cools my system just barely goes below 65F before its called to start heating to meet a "I'm home" set point.  It appears yesterday though that it had to turn on once for about 5-10 min...shame.  Overall, my system doesn't even turn on until it's needed...so a set point of 65F works.

My next project will be installing XPS insulation on my crawl space walls and the rim joists.   My downstairs wood floors are pretty dang cold and insulating the crawl space walls and rim joists should significantly help it...at least that's what people say.   I'm still a little skeptical given that I feel like insulating the floors themselves would be best...although i guess insulating at the source makes sense too. 

A side note to this...I used my handy Black and Decker  thermal leak detector to check out the temperatures in the crawl space.  On a 26F morning...I found that my brick walls which are exposed to the air were somewhere around 38-41F (some small corners registered at 32F!).  Very cold!  The walls that were not exposed (i.e. underground) were 50-55F...so 10-15F warmer.   The crawl space air itself was 59F.  So apparently if I insulate the walls, while letting in a little HVAC air (just a smidgen) I can keep the crawl space significantly warmer which will make my floors warmer.

That should be fun.  When I finally get around to it, I'll post a bunch of pics to show how I did it and hopefully include results...unless we have another freakishly warm January/February like last year.

November 2012 Energy Bill...Second lowest usage ever!

I'll tell ya...if I knew that changing out my hot water heater was going to make this big of a difference, I would have done it a long time ago.  Below is my energy usage information for the November 2012 Duke Energy bill:

November 2011 Bill
Total Energy Usage:  734 kWh
Days:  29
Average Daily Usage:   25.31 kWh/day
Billed Amount:  $73.20

November 2012 Bill (October 2 - November 1)
Total Energy Usage:  509 kWh
Days:  30
Average Daily Usage:   16.97 kWh/day (32.97% reduction from 2011)
Billed Amount:  $58.14
Absolute Savings:  $15.06
Adjusted Savings for Increase in Rates (@ $0.114/kWh):  $24.94

Recall in my October post, I noted that my previous low was in June 2011 where we used 526 kWh which equates to an average daily usage of 17.53 kWh/day.  So our November usage was again, lower than I previous low.  And last month, we had the heat on for at least half the month.

As for new projects, I posted about installing the Ecobee last month.  Following the data online, the system is certainly is maxing out the first stage, which is more efficient, as I want it to do.  

We also just bought ourselves a new fridge.  That will be installed next week and should reduce our energy usage by about 0.43 kWh/day.  Yeah...not a lot, but my fridge will bigger (it'll finally fit a platter) while still reducing usage.  And we got it $1500 cheaper (New @ Sears outlet + Energy Star Tax Weekend). I'm OK with that.

And I need to get back on the HTPC project.  I can get the PC to shutoff...but turning back on is an issue I'm still working on.  I did get myself a new router that'll allow me "wake-on-LAN"...which means it'll allow me to turn on the PC remotely when I want to say...set a new recording.  Again...this will take a while to figure out and I'm sure I'll require help from my Dad and Brothers as they are much more astute than I at Ubuntu Linux.

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...

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.