How efficiency makes solar affordable

By Reid Smith

October 27, 2010

When solar energy companies think about how to reduce the cost of their product, typically a lot of time and money goes toward increasing the efficiency of solar panels and their manufacturing process. Reducing the production cost decreases the final cost the consumer will have to pay.

However, few solar companies start by making the building more energy-efficient, even though this effort can significantly drop consumer costs. Energy efficiency lowers the demand for energy in a building. If a building needs less energy, it requires fewer solar panels, which drives down the cost of the installation for the building owner.

But you may be wondering, how significant are the energy savings in a building after energy efficiency upgrades?

Buildings are large energy consumers, accounting for 40 percent of US energy consumption, according to the US Department of Energy. Homes make up 22 percent.

Not only are buildings big energy users, but they are also big energy wasters. In fact, 40% of the energy we use in buildings is wasted due to poor insulation and air leaks.

So the first thing to do is improve the building envelope. After that, it’s important to consider how solar energy will be used in the building and what kind of installation is most efficient. People tend toward solar photovoltaic panels because PV has become the image of solar energy, said Rick Reed, president of Solaray Corporation, at the Solar Power International conference in Los Angeles earlier this month.

But solar PV is typically only about 20 percent efficient, whereas solar thermal is about 90 percent efficient. “Many people are heating their water from solar PV instead of using solar hot water systems,” he said. “This doesn’t make any sense.”

Solar thermal systems use much simpler, reliable technology and are much cheaper to install than PV systems. Still, they are largely an after-thought in the US.

For consumers, the cost of solar thermal and energy efficiency upgrades are typically much less than solar PV installations. However, most consumers interested in upgrading their homes to solar do not realize how much energy their houses could save before installing solar PV. And historically their solar installers have not told them either. Why would a solar PV installer want to promote energy efficiency if it would translate to selling fewer panels?

Thankfully, that’s changing, partly because new financing options focus on reducing the overall cost of solar for the consumer, rather than on simply selling them solar panels. As a result, more solar companies are beginning to move into the energy efficiency business. SolarCity is one example of a company that now combines energy efficiency services with solar installation.

This has huge implications. Retrofitting 40 percent of the residential and commercial building stock in the US would create over 625,000 full-time jobs over a decade, spark $500 billion in new investments, and generate as much as $64 billion a year in cost savings for ratepayers, according to a September report by The Center for American Progress.

So if you have been scared away by daunting up-front costs of solar, now may be the perfect time to get a home energy audit and begin discussing solar financing options available in your area. You may be surprised what you find.

To read the full report by The Center for American Progress, Efficiency Works:Creating Good Jobs and New Markets Through Energy Efficiency, go to http://www.americanprogress.org/issues/2010/08/pdf/good_jobs_new_markets.pdf

Reid Smith is the editor of Energy Efficiency Markets.