Multifamily Affordable Solar Housing (MASH)

Program Overview

The Multifamily Affordable Solar Housing (MASH) program provides incentives to offset the costs of installing new solar energy systems on multifamily, affordable housing buildings in California. The program began on November 16, 2007, when the California Public Utilities Commission set aside $108 million for a multifamily, low-income incentive program within the larger California Solar Initiative Program. MASH received renewed funding in 2015 in the amount of $54 million and reopened the program to waitlisted participants on August 3, 2015.

The goals of the MASH program are to improve the quality of affordable housing, decrease energy use and costs for occupants and encourage the use of high-performance solar systems that are beneficial to California’s environment.

Who Benefits from the Program?

The MASH program applies to multifamily, affordable housing buildings with new solar-panel energy systems. Typically, it is the owner of the multifamily complex that applies for the incentive in order to offset the cost of installing a new solar energy system for common areas, as well as to reduce the monthly energy costs for low-income tenants.


The MASH program provides post-installation, fixed rebates, which are calculated based on the size and expected performance of the solar system installed. Your contractor can help you determine the size of the system you need and how to allocate percentages of the power generated by the system between common areas and tenant areas in order to maximize the benefits for both the building owner and low-income tenants.

Tenants are eligible for PG&E’s Virtual Net Energy Metering (NEMVMASH) tariff. This program allows all tenants in an affordable housing complex to benefit from energy generation credits derived from the building’s solar system. Your contractor will explain that the percentage allocated to the common area takes into account historic electricity usage, whereas the tenant percentages must be based on the square footage of the residential units. If the building meter configuration qualifies, tenants in buildings participating in the MASH program will automatically be enrolled in this tariff, which does not change their existing rate schedule.

The differentiating factor between getting the lower incentive level and the higher incentive level is for the higher. The applicant must allocate credits to tenants using virtual net energy metering and guarantee that at least 50 percent of the economic benefit of the allocated generation will be received by the tenant.

The table below summarizes the requirements for the two incentive amounts.

Adopted MASH Incentive Tracks

How to Apply

Important Note: MASH is currently closed to new applications. New funding has been allotted to the MASH program by Assembly Bill 217. Funds are expected to be exhausted by the projects currently on the waitlist. If the projects on the waitlist do not exhaust the current funding, the program will be opened up to new applications at that time.

When new applications are accepted, your contractor will help with the entire application process from materials to applications to interconnection.

Applications must be submitted through PowerClerk, an online database.


Understand Your Bill

Use the Solar Calculator

  • Get a quick estimate of the cost and size of the system you will need to power your business.

Contact Us

  • Email:

    Solar Customer Service Center

    Mailing Address
    Application Fee Submittals Only
    PG&E Solar and Customer Generation—CSI
    PO Box 7433
    San Francisco, CA 94120

    Street Address (for overnight deliveries)
    Application Fee Submittals Only
    PG&E Solar and Customer Generation—CSI
    245 Market St., MC N7R
    San Francisco, CA 94105-1797

  • Quick-Service Restaurants eBook
  • Pay it Your Way
  • Office Building Incentives