The solar collectors on my house will not be parallel to the roof but will stand up at an angle of approximately 40 degrees.  With some of the recent wind storms around Edmonton and other places in Alberta I've been quite concerned about my house if one of those storms hits again after the collectors are up.  read more... »

I read an interesting article recently about how to calculate the size of an on-demand hot water heater.  OK, while not exactly what most people would consider light reading, what I thought was interesting was how much energy it takes to generate something we take for granted.  The article discussed how running a single shower would require the incoming water to absorb energy at a rate of about 75,000 BTUs per hour and that if the tankless water heater was 80% efficient, then the heater would need to have a rated input of 94,000 BTUs per hour.  If you want the ability to run two showers simultaneously, then the numbers double so that the tankless water heater would have a rating of 188,000 BTU.  (For reference, the boiler I have for heating my house and domestic hot water can modulate  read more... »

MCZNH Solar Awnings (summer and winter positions)

The Mill Creek NetZero Home (MCNZH) will have a ground-breaking solar awning installed on its south face (introduced in Solar Awning Part 1). Essentially, it's a movable awning made out of photovoltaic (PV) modules. It will serve two functions: to shade the south windows in the summer and fall, and to tilt the modules so that they are always at an optimum angle to the sun. An analysis of the solar awning's net energy benefit follows.  read more... »

B. Heath recently sent me a link to a great local-ish company from Saskatchewan. WSE Technologies cutting-edge energy efficiency and renewable energy products. Particularly interesting is their selectio nof LED lights.

Check it out:

WSE Technologies

As mentioned in my previous posts, I've signed a contract with Taylor Munro Energy Systems from BC for a solar thermal system to help provide space heat and domestic hot water.  My contract is for system design and
major component supply - it does not include installation.

I wonder if anyone familiar with the solar industry in Edmonton could put me in touch with local installers that could help me get my collectors installed on my house.  This is the proposed south elevation:

And the proposed east elevation:  read more... »

We have trusses, and we'll have a roof by tomorrow. Nick and Adam of Green Door Builders are doing a great job of framing the house. Peter is always amazed at how little waste they create. They're only throwing out little toothpicks of plywood. On top of that they are dipping into a pile of reusable lumber that I set aside for them:

A 2x6 left behind by the cribbing crew (up top, covered with a light coating of concrete) was conscientiously reused during framing  read more... »

The Riverdale NetZero Project, one of twelve projects to emerge from CMHC's EQuilibrium Housing Initiative, is now complete. It is a groundbreaking project that is the result of many people putting in many volunteer hours. It looks like the duplexes will each actually be NetCredit homes, because their performance is exceeding expectations so far.  read more... »

I've thought about the heating system for the Mill Creek NetZero Home (MCNZH) for months now. The home will need a very tiny amount of heat because it's so superinsulated, super sealed, and passize solarized. The computer model that simulates the energy performance of the house (using HOT2000) has the MCNZH using 2500 kWh. That's roughly 6% of the heat that my renovated (with new insulation and windows) 1950s bungalow uses.  read more... »

The proper term is "ground source heat pump" (GSHP). I often get questions about this technology, and I think that there are some misconceptions out there, so here goes.

How It Works

The way I think of it, there is a magical black box that can take heat at low temperatures and "pump" it up to higher ones. In Edmonton, the ground a few feet below the surface remains at about six degrees Celsius all year round. This is seasonally-stored solar energy - it accumulates in summer and doesn't cool very much during the winter because there's just so much dirt.

So, a contractor comes and drills long holes (150 - 200 feet, I think) in the back of your yard, and runs tubing down the holes. Then, when heat is needed, the heat pump runs a fluid through the tubes in the earth, and pulls solar heat from it. The exact same effect happens in reverse.

With a GSHP, you can pull 3 - 3.5 units of heat from the earth for every unit of electricity that the heat pump uses.

The Hype - Imported From Elsewhere

Using a GSHP is a brilliant idea in Manitoba or Quebec or Vancouver Island - somewhere where no natural gas is available. The thing is, if your only choice is heating with electricity, a GSHP is in effect 350% more efficient than regular electric heating. That is, with regular electric heating (like from a resistance heating baseboard heater), you get one unit of heat for every one unit of electricity invested. As stated above, the GSHP will give you up to 3.5 units of heat for every one. That's pretty good.

The brilliance of the GSHP in other locations, though, doesn't necessarily translate to Alberta. Here, natural gas is available ubiquitously. AND our electricity is mostly derived from burning coal - the enemy of the human race.

So in Alberta, the only fair comparison for a GSHP is a super-efficient natural gas furnace.

Electricity vs. Natural Gas

Most of Edmonton's electricity is generated by burning coal near Wabamun lake. The generators burn the coal, and convert about 30% of the energy in the coal into electricity. Then, it gets sent down the power line to our great city (some of it gets lost along the way, but we'll ignore that for now). If we use the electricity in a GSHP that is 350% efficient, we get 3.5 units of heat back for every 1 put in. The thing is, we're using electricity that contains only 30% of the coal's original energy value. 30% * 3.5 = 105%. A coal-fired GSHP is 105% efficient, then, when considering the energy that was initially in the fossil fuel.  read more... »

I've started a home renovation that will include the installation of solar thermal collectors to help provide domestic hot water and help heat my house. I thought there would be other people like myself who would be interested in my experience - both good and bad. Here goes . . .

Like many people, I'm interested in increasing the efficiency of my home and reducing my gas and power expenses and would love to live in something like the Riverdale Net Zero house. Also like many people, I don't have the means to built my own net zero house. Add to this is the fact that I really like the house I'm in now and love the location and we've got a recipe for a renovation.  read more... »