Green homes: solar vs. energy efficiency
Solar gets more subsidies, but home energy efficiency may be more cost-effective.
When Ted and Astrid Olsson set out to cut their home electricity bill, they had three strong incentives to buy solar panels: federal, state, and city subsidies. But they shelved the idea in favor of insulating the attic of their San Francisco Victorian.Skip to next paragraph
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While it’s not as sexy as a rooftop rack of silicon, improving a home’s energy efficiency tends to be the more cost-effective way to trim carbon emissions. So why are politicians showering subsidies on residential solar instead?
That’s the question posed by Matt Golden, president of Sustainable Spaces, a company specializing in optimizing the energy performance of homes. He convinced the Olssons to think first about energy efficiency, but with every new solar subsidy, it gets harder for him to get homeowners’ attention and contracts.
Policymakers say energy efficiency doesn’t have out-of-the-box solutions that are easy to mandate or incentivize. Mr. Golden’s message: Try harder, or forget about meeting greenhouse-gas goals.
“Everybody strategically understands that energy efficiency is the most cost-effective place for us to spend our capital,” says Golden. “We can’t afford just to take all these [super-inefficient] houses and put really big solar systems on them that require massive rebates and incentives from the government.”
Among the states, California is furthest along in understanding its emission sources and setting specific cuts. Homes account for roughly one-third of the electricity and natural-gas consumption in California – most of it in older homes. By 2020, the state wants to cut existing home energy consumption by 40 percent.
To get there, California has incentives for both energy efficiency and rooftop solar. But it’s the solar initiative that’s gotten the buzz, helped in part by Gov. Arnold Schwarzenegger packaging it as the “Million Solar Roofs” plan. The program discounts piggyback on a federal tax credit of up to 30 percent of a system’s cost. San Francisco residents can get another $3,000 to $6,000 written off.
Stoking demand for solar can be good for energy efficiency, too, notes Molly Sterkel of the California Solar Initiative, the state’s solar incentive program.
“[I]t’s a two-way street. Solar gets some people excited about energy consumption and drives them to do energy efficiency. And I think a lot of people get energy efficiency and they still want to do more, and so they go do solar,” says Ms. Sterkel.
Ted and Astrid Olsson talked with half a dozen solar installers before a colleague advised getting a home energy audit first.
On a recent weekend, Golden and a two-man team walked with the Olssons around their four-story home. Golden’s team are like plumbers for air. Using smoke candles, they watch how air circulates through ducts and drains out of vents, and look for bottlenecks and leaks. Using a fan device known as a blower door, they measure how airtight the building is.