The Iowa Department of Revenue recently adopted regulations for the geothermal heat pump tax credit and the solar energy system tax credit for tax years 2012 through 2016 on qualifying property and equipment installed beginning January 1, 2012. The nonrefundable geothermal heat pump credit is equal to 20 percent of the federal residential energy efficient tax credit allowed for residential pumps, and the solar credit equals 50 percent of the federal residential energy efficient property credit for solar systems.