Renewable Energy Tax Credits: Tax reform provides for business tax credits for renewable energy, but not the residential credits. Solar, geothermal and ocean thermal credits were extended for three years. Solar and geothermal investments get a 15% credit for 1986 and 10% for 1987-88. Ocean thermal's credit is for 15% in 1986-88. Wind and biomass credits were extended for only two years. Both get a 15% credit for 1986 and 10% in 1987