Energy Monitoring

HI, We've recently completed our new house. Its a full ICF build in central Ontario with triple pane windows, air to air heat pump double insulated slabs and roughly 2000 sq ft of finished space. I find it big for the four of us and Its a high tech solution for sure but I build and these are the types of build people ask me about. It looks conventional but outperforms the norm significantly.  I design and sell energy systems as well so I decided to use the house as an example and monitor its energy use over the winter before sizing and installing the solar array. You can always just use the numbers off your energy bill but you cannot dive into the main users of power that way.  So I purchased an emporia energy monitor and installed it in our panel. Not an easy process but you get great detail. Is there anyone else out there monitoring closely? We talk a lot about energy here but I rarely see numbers just anecdotal reports. So, I'm putting myself out there; I'm screen shotting the daily feed (from midnight to now) and the month to date. I'll update as the month ends and monthly. I'd love to hear feedback what people think and monitoring solutions they are using. My own surprise was how much of our energy total was going to hot water. In hind site I might have invested in a heatpump driven hot water heater. The inverter system I'll be installing can divert excess solar to house loads so ill be looking into that for sure.

Cheers, David Baillie

Hi David;
Very impressive stuff!
And definitely a great example of how new houses can be built super efficiently and more self-reliant.
Way beyond my 100-year-old cabin with a vintage 12vt solar/hydro system.
I'm sure there will be others with your tech-savvy level who will understand your numbers better than I care to.
So for the other non-tech dinosaurs out there like myself.
Perhaps you can post the occasional dumbed-down synopsis of your results?

thomas rubino wrote:Hi David;
Very impressive stuff!
And definitely a great example of how new houses can be built super efficiently and more self-reliant.
Way beyond my 100-year-old cabin with a vintage 12vt solar/hydro system.
I'm sure there will be others with your tech-savvy level who will understand your numbers better than I care to.
So for the other non-tech dinosaurs out there like myself.
Perhaps you can post the occasional dumbed-down synopsis of your results?

Thomas, as much as from time to time we disagree I do truly respect you and your experiences. I'll try to provide some analogies going forward.

A full week of cold weather now. Current temperature is  -7C ( 19.4f) We have not gone above -3 (26.6) all week. Including the mechanical room which is kept at room temperature we are heating 2450 sq ft. Weekly energy required to heat to 21 degrees celcius(70f) was 73.3Kw Hr or 10.47Kw Hrs per day. (To simplify things I'm using the energy consumed by the Heat pump not the heat it produces which changes as the air temperature changes. If we were using baseboards or the electric backup in the furnace it would be 2 or 3 times more electricity.) So,  as an equivalency a watt is 3.41BTU or 3410BTU per KwHr so total BTU per day was 35702.7. Now Wood dried to 20 percent humidity is estimated to have between 6500 and 7500 BTU per Lb. Assuming the crummiest wood and a 70 percent efficiency stove that works out to 7.847lbs of wood per day... That number is the main reason we do not heat with wood. It simply was not worth the investment and insurance hit to install a wood stove. Now it will get colder here so I am looking forward to how high that number goes as the winter progresses. The plan so far is a 14 Kw solar array and where I live I can only expect 1.5 hrs of full production in mid winter from the array. The system will be net metered so i should have plenty of accumulated credits from the summer but I would like to be close to parity in winter as well in case of a power outage.

So I totally blew end of month Here are the monthly heat pump totals and dailies. I'm not sure how much of the furnace total to include as its the blower and the air exchanger. Probably not things you would have in a wood heated house so I would like to know what people think.
I've been thinking about energy conversions again. Above I believe I used a Kw to wood conversion but I didn't account for the efficiency gain for the heat pump. At this time of year I'm probably in the 3 to one range so I should probably triple the BTU numbers above. Any thoughts?
November total:
Heat pump usage 189 Kw Hrs or 6.3 Kw Hrs per day
6.3KwHrs/dayx3.41=21483 BTU resistance heating or (I estimate) 64449 BTU heat pump heating
So 4.72 Lbs of wood or 14.16 lbs of wood depending on how you figure it...
Cheers,  David

So the winter grind goes on. Honestly as a winter its been pretty mild until a few weeks ago. Of note in the last week I turned off the heat pump and did a 24 hour cycle using only the resistance heater backup in the furnace. The reason is its much easier to figure out heat loss in a house using resistance heating than a heat pump since the heat pump's efficiency changes with outside temperature. So! to the numbers!  and I'll try to give an honest accounting of them.

January 11th was a  -15 degree celcius night going up to a cloudy -5 day and a -15 night again. This was the day I went fully electric resistance as a test. total furnace heat consumption minus the blower fan was 34.5kWhrs

January 14th was an almost identical day and was all heat pump consumption was 12.4kWhrs. So that gives us a heat pump efficiency gain of 2,78... at -15 to -5 celcius... To say I'm pleased is an understatement.

Conversion time!

all electric heat: 34.5kWhrs x 3.41 = 117645BTU per 24 hrs or 25.86 lbs of crummy wood in a 70 percent efficient stove
Heat pump heat: 12.4kWhrsx3.41 =  42284BTU per 24 hrs or  9.29 lbs of crummy wood in a 70 percent efficient stove...

I started this mostly to log heat consumption through the winter and figure out how efficient the heat pump was compared to resistance heating... or wood. We might add a wood based heat source down the road or solar thermal but I am vey impressed with the heat pump so far. I would love to know if anyone else is logging energy usage at all and how. I'll admit I like crunching numbers.
Cheers,  David Baillie

My house is very similar to what you deduced as well: while electricity gets the hype today, it really is not a huge expense for me. My electric bill is only $120 a month or so, and this is in the state with the highest electrical costs, and in a cold environment. Hot water is where the majority of my energy money goes.

Sadly, I think you may be making a mistake that I made for many years regarding finances. I tracked all my expenses right down to the penny, and could tell you how much I spent at Walmart in 2010 even today, but tracking things did not do me much good. I needed to budget, and I did not do that.

Keeping track of energy costs does little if all you do is see where your energy costs are. It takes addressing them for continuous improvement. It is not easy to do, and can be demoralizing if you are honest with yourself. In your case you have a reason to do that; you want to promote your own house in order to market heating systems for others, and that is a valid point for sure. But I also see that as a very slippery slope. It is easy to track what others are not, then compare consumption to them.

I saw this back in the 200o"s. People would pay $12,000 for an outside wood boiler when what they really should have done was pay $12,000 for new windows and insulation and heated their home with a tiny woodstove.

Today I see the same thing. people pay a lot of money for elaborate solar arrays when really the best choice is to conserve energy from the start. People do this because it is something other people can gush over and admire, while you cannot see conservation as the genius that it is, because there is nothing there to see! This is why I love Permiculture Principals, it is unassuming, and I love that. I want amazing results, but I don't want to be the center of attention, nor my home to be. I want to be, and have always been, a Gert, and it has paid off well for me.

Conservation ALWAYS will be the better choice. When you don't pay for something, 100% of that money stays in your pocket. When you buy something, it is paid back over time, but also has purchase, maintenance and end of life costs too. The only free lunch in the world, is the lunch you go without.

Hmm... Personally conservation always goes hand in hand with production for me. I'm not tracking to save money I'm tracking to know. Solar is big and flashy for sure but the gold in this house is the windows and the double insulated slabs. I find People in our society seem to focus to a great extent on solving problems from the production side instead of focussing on the consumption side. I believe we are on the same page on this.
Cheers, David Baillie