Between 35 and 50 percent of most American city surfaces are covered with pavement. All of that pavement retains heat, contributing to what is known as the urban heat island effect.
About 40 percent of the average city's pavement is taken up by parking lots, so covering parking to alleviate some of that heat seems like a good idea. According to an article in the Washington Post, covering those lots with solar panels seems like a no-brainer. Not only do solar-covered parking lots make for cooler cars and contribute to increased vehicle fuel efficiency, depending on the size of the array, such a carport could generate a lot of energy. And while there are solar carport installations out there, they aren’t by any means plentiful. According to a study released by GTM Research last year, by the end of 2014, there were an estimated 600 MW worth of solar canopies in the United States. So why aren’t there more of them?
The main reason is that such systems are very expensive to build. In fact, according to truSolar, which assess the financial risks of solar PV projects, solar carports are the most expensive type of system to build.
The economics of installing solar canopies also varies by state. The GTM Research report found that carport solar installations are primarily happening in states that offer financial incentives to support their development, such as Arizona, New Jersey, Maryland, Massachusetts, New York and California.
In California, for example, solar carports have been supported by the California Solar Initiative and the Division of the State Architect, which oversees construction on many public buildings.
Fortunately, the cost for solar carports is coming down, and as prices continue to decline, the market is expected to grow. GTM Research forecasts that the market will grow each year until the federal solar Investment Tax Credit expires at the end of 2016.
Photo of solar carport via Shutterstock.