The amount of solar capacity installed in the US is forecast to nearly double to 40GW by 2017, up from 20GW in 2014, according to a new video report from the US Solar Energy Industries Association (SEIA).

Solar, the fastest growing source of renewable energy in America, will be producing enough energy to power eight million homes by 2017, with all solar markets expected to grow 25-50% in this period. It is expected that 16 states will install more than 100MW solar in this time.

SEIA's video cited policies such as the Solar investment tax credit (ITC), net energy metering and the Renewable Portfolio Standard (RPS) as major drivers for the growth.

Looking back, since 2010, the average price of a panel has dropped 63%, while the average price for a PV installed systems has dropped 50%.

From 2004 to 2014, cumulative investment in the industry rose from US$2.6 billion to US$71 billion. Installed capacity grew from 500MW to 20GW and the number of utility-scale plants grew from 100 to 1,100.

The US industry currently employs 174,000 people, adding workers at rate 20 times faster than overall economy.

SEIA president and chief executive Rhone Resch said: “In 2004 only two states had 10MW of installed solar capacity, yet a decade later, 35 states had topped that threshold – and 20 states had more than 100MW? But here’s the best news of all: we expect to double our total capacity in the next two years alone.”