(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  read more... »

Saturday, March 20

• Seminar: 10am to 12:30pm
• Tours: 2pm to 4pm

Seminar: Designing and Owning a NetZero Energy Home

• Grant MacEwan University, CN Theatre Rm. 5-142, 105 St. Building at 105 St. and 105 Ave
• Peter Amerongen (builder), Gordon Howell, P.Eng. (solar engineer), Conrad Nobert (Mill Creek homeowner)
• Seminar and tours: No need to register. Cost: free

Open House Tours - see ideas you can use on your own house

• energy- and water-efficient construction and appliances reduce space heat by 65%, hot water by 75%, and
  electricity use by 50% for upgrade cost of less than $20,000. All electric. No need for natural gas line.
• air and water heat recovery, LED lighting, rainwater harvesting, passive solar, active solar, solar electricity
• sustainable materials, healthy indoor air quality, eco-landscaping, net zero emissions

The Bricor Hand-Held Showerhead only uses 4.2 litres (1.11 gallons) per minute

I've never needed a reason to conserve water. Simply knowing that half of the world’s population lives without easy access to it is enough to make me grateful for my easy life.

Other than gratitude, the reasons to conserve water are excellent:

• Carbon Dioxide: Saving 1000 litres (one cubic metre) of water averts the emission of 1.75 kg of carbon dioxide (source).
• Cost: Water costs me about $2.64 per 1000 litres to deliver and treat.
• Cost Again: Water is very expensive to heat.
• Contamination: When I use water in my house, it returns to the North Saskatchewan river more contaminated than if I had left it there.
• Water Security: Our glaciers are melting. We may one day be water insecure, so having infrastructure in place to reduce its use is a good thing.

Toilets account for roughly 1/3 of our water use. In the Mill Creek Net Zero Home we installed dual-flush toilets.

Our Toto Dual-Max toilets “get the job done” while keeping water use to a minimum.

We decided on Toto Aquia Dual-Max toilets because they reportedly worked well, and our plumbing supply company stocked them. So far, so good.  read more... »

The temptation has always been there for eco-house builders. It’s those damn windows; they are just so useless once the sun goes down. There must be some way to insulate them once they no longer need to be seen through, right?

Moisture

The answer is yes, but not cheaply. The biggest problem is moisture. If you insulate a window from the inside without a perfect air seal between the heated space and the cavity between the window covering and the window, moisture-laden air will flow into said cavity. When that happens, the moisture will condense on the window. Take it from green building pioneer Rob Dumont:

Back in the 70s I had a small house with lots of south windows. I experimented with interior rigid insulation on the windows. Some observations:

You need a very tight air and vapour barrier on the warm side of the insulation. I did not have either, and condensation would readily form on the window. I used a 2 inch thick piece of beadboard as the insulation. The windows were double glazed sealed units with an R value of about R2. Even more condensation would form on the window when the insulation was removed, as the warm, moist air could then, unimpeded, hit the window.  The condensation would run onto the sill. I actually got quite sick from the mould that grew on the lower corners of the windows. Never again.

R Value

We felt compelled to buy window coverings as soon as we moved into the Mill Creek NetZero Home  read more... »