California Solar Initiative - Low-Income Solar Water Heating Rebate Program

May 16, 2023


Note: This program is no longer available. 

The California Public Utilities Commission (CPUC) voted in October 2011 to create the California Solar Initiative (CSI) Thermal Low-Income program for single and multifamily residential properties. The program offers rebates that are substantially higher than ones provided under the CSI-Thermal General Market Program.

The program is only available to customers who currently heat their water with natural gas in the service territories of Pacific Gas and Electric Company (PG&E), San Diego Gas & Electric (SDG&E), and Southern California Gas Company (SoCalGas) . For single-family residences, customers must be participating or have previously participated in an Energy Savings Assistance Program (ESAP), and the property must remain low-income for at least 10 years. For multifamily housing property, at least 50% of all units in the structure must be occupied by ratepayers who have participated in an ESAP.  The residences must also meet the definition of low-income residential housing in California Public Utilities Code 2861(d). Additional requirements are outlined in the CSI Thermal Handbook.

Incentives will be determined based on the expected performance of the system using the SRCC rating and the specific orientation of the system. Incentives will step down over time in 4 steps as program participation levels are met. See the website above and the CSI Thermal Handbook for more information.

Interested customers should contact the appropriate program administrator:

Pacific Gas and Electric:
Phone: (877) 743-4112
Center for Sustainable Energy (SDG&E territory):
Phone:  (877) 333-SWHP
Southern California Gas Company:
Phone:  (800) Gas-2000

Program Overview

Implementing Sector: State
Category: Financial Incentive
State: California
Incentive Type: Rebate Program
Web Site:
Start Date:
Eligible Renewable/Other Technologies:
  • Solar Water Heat
Incentive Amount: Step 1 Incentive Rates (contact utility to determine current incentive levels):
Single-Family Low-Income: $25.64 per therm displaced
Multi-Family Low-Income: $19.23 per therm displaced
Maximum Incentive: Single-Family Low-Income: $3,750
Multi-Family Low-Income: $500,000
Equipment Requirements: Systems must be used in connection with a natural gas water heater. Systems used in connection with an electric water heater are ineligible.
Systems must be SRCC certified.
Installation Requirements: Systems must be installed by an appropriately licensed contractor


This program has 2 incentives
Technologies: Solar Water Heat
Sectors: Low Income Residential
Parameters: The incentive is 25.64 $/therm displaced, The incentive has a minimum of $3750.00
Technologies: Solar Water Heat
Sectors: Multifamily Residential
Parameters: The incentive is 19.23 $/therm displaced, The incentive has a minimum of $500000.00


Name: CSI Thermal Handbook
Effective Date: September 2013
Name: CPUC Decision 11-10-015
Date Enacted: 10/6/2011

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.