The Energy Information Administration (EIA) reports that grid-connected solar photovoltaic (PV) solar installations topped 3,536 MW in 2011.
EIA examined residential, commercial and industrial, and utility owned projects. EEIA added that data collection has improved in recent years, but it is by no means definitive.
In a report from the latest “Today in Energy,” EIA reported a breakdown that appears to be approximately 1,000 MW for residential; 1,500 MW for commercial and industrial; and slightly above 2,000 MW for utility scale.
The research falls somewhat in line with previous reported estimates from trade organizations using slightly different surveys. The EIA said tracking the rapid growth of solar present several challenges and that it is improving its methods.
EIA’s utility-scale electric generator survey has a threshold of 1 MW for reporting and, thus, does not capture most customer-sited installations. However, in 2010, electric utilities started reporting to EIA the capacity of their customers’ behind-the-meter generation. EIA now reports this combined data.
Regulatory capacity limits on the size of net metered installations vary by state; some are above the 1-MW threshold for utility-scale reporting, and some states have no limit at all.
The Interstate Renewable Energy Council (IREC) prepares an estimate of total PV capacity developed using a combination of state incentive program data, information from utility companies, and collaboration with other organizations. The IREC 2011 estimate is between 3,200 and 3,600 MW. EIA’s report of 3,536 MW falls towards the high end of this range.
A previous report by the Solar Electric Power Association (SEPA) 2011 Utility Solar Rankings Report showed that utilities interconnected more than 62,000 PV systems of all sizes. These new systems resulted in almost 1,500 MW of new utility solar capacity, more than twice as much as was added in the previous record year, 2010.
That study showed that 39 % of new solar capacity came from utilities owning or contracting for solar power. Large solar projects, greater than 10 MW each, represent the bulk of this utility-led capacity. The remaining 61 % came from residential and commercial installations.
For the fourth straight year, utilities integrated a record amount of new solar power, despite the recession. Utility-driven procurement represented 39% of the new solar capacity in 2011, versus 9% in 2008. As compared to the more traditional customer-oriented market segment, this sector consists of direct wholesale purchases and utility-owned projects, which were 26% and 13% of the market respectively. Large solar projects (> 10 MW) make up the bulk of this capacity with an estimated 18 projects totaling 332 MW, up from 226 MW in 2010. SEPA anticipates that this utility segment could increase to 1500 MW in 2012, equivalent to the 2011 market in its entirety.