January 26, 2009
Can we heat and cool our buildings without coal, oil or gas? This is one of the big global warming challenges. One solution is Zero Carbon Buildings - super-insulated, triple-glazed buildings that need almost no heat.
In Germany, 6,000 Passivhaus buildings use 90% less energy than the Germany average – 9-16 kWh per square meter instead of 160. In winter, they need no heat when it’s minus 10C outside, and in summer when its 35C outside it’s only 26C indoors.
For heat, there are several options, including solar hot water; heat exchange from air, ground, water, and sewage; district heating using biogas from compost and sewage; solar hot water gathered in summer and stored underground for use in winter; biodiesel from wastes, algae, or seaweed; solar walls and catchments; super-efficient wood stoves, pellet stoves, wood gasification boilers and masonry heaters (in rural areas); and masonry night storage heaters that use off-peak green electricity.
The way to get there is by Green Building Codes that make it mandatory. Britain is requiring all new buildings and ten new towns to be zero carbon by 2016. Austin, Texas is requiring all new homes to be Zero Energy Capable by 2015 - 65% more efficient than the code, with protected roof space for solar PV and hot water.
BC’s new Green Building Code is to be published soon, but due to pressure from the building industry it is unlikely to go far enough. To make up for this, it must at least allow municipalities to create rules that exceed the Code: this is how the best pioneering progress is being made, by experimentation at the local level. This is how Spain came to have a law requiring solar hot water on all new buildings, for instance.
What about our existing buildings? This is a far bigger challenge. In Berkeley and San Francisco, every building is required to have an energy upgrade whenever it is sold, transferred, or renovated, which is a very smart move. By 2006, 12,000 Berkeley residences (30% of the building stock) had been upgraded, resulting in 25% - 50% less energy use.
Another approach is to get Energy Saving Companies (ESCOs) involved, financing the work from the energy saved. In Cambridge, Massachusetts, a $100 million ESCO partnership is visiting all 23,000 buildings, offering free energy audits, and retrofits that can be financed through the energy savings.
Ann & Gord Baird’s solar thermal zero carbon cob house in the Highlands. www.eco-sense.ca
Utilities like BC Hydro can also play a role. Austin Energy provides free home-energy improvements to customers with low-to-moderate incomes and rebates for energy investments. Seattle City Light has numerous programs to assist with energy upgrades, and in Colorado, Fort Collins Utilities provides Zero-Interest Loans for Conservation Help (ZILCH).
Retrofitting existing buildings to become Zero Carbon is a big challenge, especially for baseboard-heated homes that have no ducts or under-floor pipes to distribute green heat.
One big disadvantage in BC is our very low price of electricity, which removes the incentive for people to care. The higher the price of power, the more people care about efficiency and the less energy they waste – so increasing BC Hydro’s rates and using the income to support energy saving measures including targeted programs for low income households is a very sound approach.
First published in EcoNews: A monthly newsletter funded by your donations that dreams of a world blessed by the harmony of nature, the pleasures of community, and the joys of personal fulfillment, guided and protected by our active citizenship.