Creates the Geothermal Homes and Business Act. Provides that, beginning January 1, 2026, the long-term renewable resources procurement plan developed by the Illinois Power Agency shall include a Geothermal Homes and Business Program for the procurement of geothermal renewable energy credits. Sets forth provisions concerning the geothermal heating and cooling system calculation methodology; Program block allocation; Program block pricing; approved vendors; contract terms; utility cost recovery; extenuating circumstances; administration of the Act by the Illinois Power Agency; and the prohibition of double claiming geothermal renewable energy credits. Effective immediately.