Using a well designed solar hot water system will have a dramatic effect on your home’s carbon footprint, and could help provide significant savings on your energy cost.


A solar hot water heating system uses the radiant energy from the sun to heat water for use in one’s home. If you’re not familiar with this technology, you’ve likely seen it before on a roof and mistaken it for a solar photovoltaic (PV) system. Solar thermal, also known as solar hot water, similarly collects solar energy using roof-mounted panels or tubes, but rather than converting that energy into electricity as with solar PV systems, solar thermal systems store the energy in water, heating it. That heated water is then fed into the home and used for hot water in faucets, showers, and appliances. A well designed system typically displaces around 70% of energy used in heating hot water throughout the year.


Generates warm water for your home using the sun’s thermal energy.
Can supplement your regular water heater.
Has the potential to eliminate your entire water heating bill.

Works well in cold climates– meeting the heating demands even on the coldest day.

Incentives for Thermal Hot Water

Mass Save HEAT Loan

If you’re installing a solar hot water system, you may be eligible for a 0% interest HEAT Loan from Mass Save. You can finance up to $25,000 over the course of 7 years for home energy efficiency upgrades. While fuel prices fluctuate for many projects the energy savings can often come close with covering the principle payments each month. Find out more about Mass Save’s HEAT Loan program.

Alternative Energy Credits

Solar hot water system installations in Massachusetts qualify for the Alternative Energy Certificate (AEC) program. With this program, non-emitting renewable technologies generate certificates based on their energy production. These certificates are sellable to utility companies looking to meet state-mandated renewable energy goals. The revenue earned from these certificates will help you to further save on your solar hot water or air source heat pump installation. Learn more about AECs.

Rebates & Tax Credits

Massachusetts leads the nation in energy efficiency and has many incentives and rebates available to help make clean heating technologies affordable. Learn more about rebates available from Mass Save, or through the MassCEC. Mass Save heat pump rebates have increased starting in 2022, and eligible air source heat pump equipment could qualify for a rebate of up to $10,000. Learn more about Mass Save heat pump rebates.


Just like solar electric panels, your solar thermal panels will work during the wintertime. They will generate less hot water than in sunnier months, so you may have to use your backup water heater more often during cold weather. Any snow that is accumulated on the panels will typically slide off on its own when the sun comes back out. Solar thermal systems installed will also have freeze protection.


Your Guide to Solar Thermal Hot Water