There are significant “Renewable Energy Tax Credits” for up to 30% of the costs of major energy installations. These credits are unlimited, and include labor on installation for the following:
solar water heaters
solar panels
geothermal heat pumps
small wind turbines
fuel cells
The 30% credits decline through 2021, and are as follows:
2019: 30%
2020: 26%
2021: 22%
The installations must be installed in a home you own and use as a residence (no rentals, but second homes qualify).
These energy tax credits are non-refundable, but can be carried-over to a future tax filing year. More information can be found on the Energy Star Renewable Energy Tax Credits website. Prior to a Congressional budget deal, only the solar credits had remained in place.