(photo courtesy of Edmonton Real Estate Weekly)

I have the first set of electricity consumption numbers for the house (see the data at the bottom of the post). Some comments about the numbers:

• It was sunless winter. I found that sunshine had a greater effect on the performance of the house than temperature. People have commented that January was mild, but we burned a lot of wood because we only got 5-10 hours of total sunshine (92 hours is normal).
• Our heating needs dropped off a cliff once the sun started shining on a consistent basis. In the last six weeks all of the thermostats have been turned off, and we have only burned two fires.
• Of note: we installed water-efficient showerheads on January 12 (Bricor, 1.11 GPM versus about 2.25 GPM previously). Also, until January 12 there was another adult in the house (so  three adults, two children).

So far…

• That said, we went through a LOT of wood this winter. We would burn for four hours straight in the evening and then another hour in the morning when it was –25 and there was no sun.
• once the sun started shining, it warmed up, and we were using efficient shower heads, our electricity usage dropped to 8.6 kWh/day. We are very conscientious about power use, but on the other hand we cook a lot in the house.  These LAME numbers (lights, appliances and misc. electricity) are below our yearly estimate of 5150 kWh (8.6 kWh/day would be 3139 kWh annually).
• our movable PV awnings are not yet up. The production numbers are for 12 modules out of an eventual 32 (the last 20 are bifacial).
• the basement was not heated - it will be when someone moves in, plus they will be taking showers, etc.
• Based on what I seen, I think that this house will be net zero house at least in the above average years. It remains to be seen if it will make the grade for an average year.

The numbers:

Total: 2009 Nov 9 - 2010 Mar 22 (133 days)
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Total Household Use:   2451 kWh
Average Daily Household Use For Period: 18.4 kWh per day
Solar Energy Exported:   405 kWh
Solar Energy Used In-House:  223 kWh

2009 Nov 9 - Dec 11 (32 days)
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Total Household use: 590kWh
Average Daily Household Use For Period: 18.4 kWh per day
Solar Energy Exported: 90 kWh
Solar Energy Used In-House: 42 kWh

2010 Dec 11 - Jan 12 (31 days)
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Total Household use:  832 kWh
Average Daily Household Use For Period: 27 kWh per day
Solar Energy Exported: 9 kWh
Solar Energy Used In-House: 36 kWh

2010 Jan 12 - Feb 11 (29 days)
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Total Household use:  699  kWh
Average Daily Household Use For Period: 24 kWh per day
Solar Energy Exported:  43 kWh
Solar Energy Used In-House: 88 kWh

2010 Feb 11 - Mar 22 (38 days)
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Total Household use:   328 kWh
Average Daily Household Use For Period: 8.6 kWh per day
Solar Energy Exported:   263 kWh
Solar Energy Used In-House:  55 kWh