Solar photovoltaic systems generate electricity using technologies that capture the energy in sunlight. Many parts of the United States—especially the Southwest—have abundant solar resources (see Figure 5, which shows estimates of the average daily total radiation for flat plate solar collectors). Before investing, however, firms should commission a thorough professional study of a specific site’s solar resources. Even if it reveals lower or moderate resources, solar power could still be financially attractive, depending on financial incentives and regulatory context.

Credit: National Renewable Energy Labs and WRI.