Solar water heaters are also covered by the Residential Clean Energy Credit. You can claim up to 30% of the costs for solar water heater installations. The credit applies to both new and existing homes located in the United States. Qualified expenses include the costs of solar water heater property and related installation. Some financial institutions offer low-interest loans specifically for energy-efficient home improvements. These loans can help cover the upfront costs of installing a solar water heater. Look into local banks or credit unions that participate in such programs.