A new study by Lawrence Berkeley National Laboratory shows that the average cost of installed solar photovoltaic (PV) systems in the U.S has declined from $10.50 per watt in 1998 to $7.60 per watt in 2007. The study examined 37,000 grid-connected PV systems in 12 states.
The study attributed the decline mostly to decreases in non-module costs, such as the cost of labor, marketing, overhead, inverters and the balance of systems.
Direct cash incentives provided by state and local programs declined over the 1998-2007 study period. Other sources of incentives, such as federal incentive tax credits (ITC), increased. For example, as a result of the increase of federal ITC for commercial systems in 2006, total after-tax incentives for commercial PV were $3.90 per watt in 2007, an all-time high.
