Solar power in Iowa is in limited, with only 27 MW installed by 2015, ranking the state 29th among U.S. states. Iowa's position as a major wind power provider may have limited early solar investment. Solar on rooftops can provide 20% of all electricity used in Iowa. On June 7, 2012, Sky Factory in Fairfield became the first company in the state to generate all of their electricity from solar power, with the installation of a 54 kW 3500 sq. ft. solar array. Prior to that one of the largest arrays was the 15.75 kW array on the Marshalltown Public Library. An 800 kW array near Kalona was the largest in the state when it went online in July, 2014.
Net metering is available continuously to all consumers generating up to 500 kW, one of the best policies in the country but is given a B because of not being available to large, megawatt users. A feed-in tariff is available for customers of the Farmers Electrical Cooperative for up to 25% of their electricity. It pays 20 cents/kWh for electricity generated, none of which can be directly used – a separate meter is required, in a parallel connection, making it a power purchase agreement, instead of a feed-in tariff. The state of Iowa has proposed a feed-in tariff, in Senate bill SF 225. A separate rate applies for systems less than 20 kW and systems from 20 kW to less than 20 MW.
In December 2011, Des Moines-based MidAmerican Energy Holdings, a Berkshire Hathaway company, purchased the Topaz Solar Farm, which when completed, at 550 MW, was the largest in the world.