Commercial Solar Hot Water Rebate Program

February 27, 2023


Beginning in August 2011, the Massachusetts Clean Energy Center (MassCEC) will provide grants* for feasibility studies of commercial solar hot water systems through the Commercial Solar Hot Water Program. This program is open to residential buildings with five or more units, as well as commercial, industrial, institutional, and public facilities that will require nine or more collectors. Smaller projects should apply under the Residential and Small-Scale Solar Hot Water Program.

Commercial Solar Hot Water rebates are available to electricity customers served by the following Massachusetts investor-owned electric utilities: Unitil, National Grid, and Eversource. In addition, customers of certain municipal lighting plant (MLP) utilities are eligible. Only entities that live in territories that contribute to the MassCEC Renewable Energy Trust Fund are eligible for a grant.

Feasibility Study Rebates

Existing buildings, as well as new construction projects, offsetting electricity, oil, propane, or steam with solar hot water systems are eligible for feasibility study rebates. Only project sites with government, non-profit, agricultural, and affordable housing uses are eligible for feasibility study rebates. Up to $5,000 is available per project, with a minimum cost share of 5%. The maximum amount of awards per feasibility study consultant or system owner is $50,000.

To be eligible, building owners must hire an experienced consultant to complete the feasibility work. The project location must be appropriate, receive enough sunlight, and the building must have year-round hot water needs. The application must also demonstrate that the time frame and budget required for the feasibility study are "reasonable." The consultant completes and submits the application and supporting documentation (such as aerial photos, copies of electric bills) on the building owner's behalf. All projects must be approved before feasibility study work begins.

Construction Rebates

New construction projects and existing commercial buildings offsetting natural gas, as well as electricity, oil, propane, or steam with solar hot water systems are eligible for construction rebates. Third-party owned systems are also eligible. Rebates differ depending on whether the system is OG-100 or OG-300 certified. 

For OG-100 certified systems, the base rebates are as follows:

  • Standard: (Average of C&D SRCC OG-100 Rating) x (# of collectors) x ($50)
  • Non-Profit/Public Entity: (Average of C&D SRCC OG-100 Rating) x (# of collectors) x ($100)
  • Multi-family Affordable Housing: (Average of C&D SRCC OG-100 Rating) x (# of collectors) x ($135)

The OG-300 rebate calculation is available upon request by the primary installer, subject to MassCEC approval. Base rebates under the OG-300 calculation are as follows:

  • Standard: $0.17/kBTU
  • Non-Profit/Public Entity: $0.26/kBTU
  • Multi-family Affordable Housing: $0.35/kBTU

System owners with solar photovoltaic (PV) systems located on the same facility are eligible for a $500 adder. The PV system must be grid-tied and at least 1 kW (DC). An adder is also available for projects installing metering equipment; the rebate is the lesser of the installed cost of the metering unit or $1,500.

Maximum Rebates for all systems are as follows:

  • Standard: 40% of eligible project costs, limited to $100,000 ($101,500 with maximum metering adder)
  • Non-Profit/Public Entity: 65% of eligible project costs, limited to $100,000 ($101,500 with maximum metering adder)
  • Multi-family Affordable Housing: 80% of eligible project costs, limited to $100,000 ($101,500 with maximum metering adder)

Applications are completed online by the installer.  Pre-approval is required, and MassCEC may inspect any system after it is installed.

Program Overview

Implementing Sector: State
Category: Financial Incentive
State: Massachusetts
Incentive Type: Rebate Program
Web Site:
Administrator: Massachusetts Clean Energy Center
Start Date: 08/04/2011
Eligible Renewable/Other Technologies:
  • Solar Water Heat
Incentive Amount: Feasibility Study Rebates: Up to $5,000 per project
Construction Rebates: $50*number of collectors*SRCC Rating (Private); $100*number of collectors*SRCC Rating (Public/Non-Profit); $135*number of collectors*SRCC Rating (Affordable Housing)
Metering Adder: Up to $1,500
PV Adder: $500
Maximum Incentive: Feasibility Study Rebates: $5,000 per project; $50,000 per consultant or owner
Construction Rebates: $101,500 (including the maximum metering adder value)
Eligible System Size: Commercial Buildings: Must include at least nine collectors
Equipment Requirements: Must be new, OG-100 or OG-300 certified, 10 year warranty (collectors), 2 year warranty (other system components), 2 year warranty (comprehensive installation)
Installation Requirements: Must be installed where the collectors will receive at least 5 hours of sunlight a day (75% shade-free).


This program has 1 incentives
Technologies: Solar Water Heat
Sectors: Commercial, Industrial, Local Government, Nonprofit, Schools, State Government, Federal Government, Tribal Government, Agricultural, Multifamily Residential, Institutional
Parameters: The incentive has a minimum of $101500.00


Name: Massachusetts Clean Energy Center
Address: 63 Franklin Street, 3rd Floor
Boston MA 02110
Phone: (617) 315-9300

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.