October 16, 2014
By Brad Plumer
The price of residential solar power in the United States keeps dropping. Back in 2008, the cost of installing a rooftop solar system was about $8 per watt. Today, it’s about half that — and still falling.
Up until 2012, that price decline was largely due to the fact that the photovoltaic panels themselves were getting cheaper, driven by a glut of Chinese manufacturing and various technology improvements. This story got a lot of attention in the press.
But things have changed a lot this past year. Yes, solar modules are still getting cheaper, but the decline is now much more gradual (particularly now that there’s no longer a glut of manufacturing). Instead, as this chart from GTM Research shows, the major innovations nowadays are in “balance of systems” costs — incremental improvements in design, engineering, labor, and financing for rooftop solar systems… Read more