We visited a demonstration solar energy house in Guelph, Ontario and Teresa Paul from Nexus Solar Corp. who designed it. In this very standard looking house we could see the bringing together of all the basic concepts of solar energy for both winter and summer. To emphasise that this did not look like one of those spaceship houses is important and an indicator that solar energy considerations are becoming cost effective and moving into mainstream housing.
First is the question of Solar Architecture -- the size and placement of windows. The first photo doesn't look like anything special, but those two extended columns actually permit the extension of the roof without it being apparent. This extended roof totally shades this room from the hot summer sun, reducing air conditioning costs. The well placed skylight brings light into most of the rooms in this open mezzanine layout, reducing electrical lighting costs all year long. In fact, when proper sizing and location of windows as well as proper shading is taken into consideration, solar architecture can cut heating costs by 20% and cooling costs by 10%.
There are solar heating panels on the roof that have liquid flowing through them, capturing the heat of the sun and providing both domestic hot water and space heating for the house. In the summer time this can provide all the hot water needs for a family of 4, and displace a lot of fuel based energy the rest of the year by providing some heat even on a sunny winter day. Of course in Canada, you need a full heating system as well because the sun cannot provide for all our heating needs.
One of the traditional drawbacks to using Photovoltaic panels that generate electricity directly from sunlight has been the need to store that energy in large banks of batteries. In this house, the photovoltaic panels are tied directly into the municipal electrical grid. During periods where they generate more electricity than the house needs, that excess electricity flows back into the municipal system, causing the local meter to roll backwards. It is like storing the energy. The electrical utility won't pay you the same rate for your electricity that they charge you for theirs, but eliminating the batteries and evolving cooperation with electrical utilities are two steps that are making Photovoltaic panels more and more financially feasible.
Teresa has calculated that this house will save about 2,000 Kilos of CO2 a year. She works with Nexus Solar Corp. in Saskatoon, Saskatchewan.