In California, the Multifamily Affordable Solar Housing (MASH) Program launched in 2009 along with its sister program, the Single-Family Affordable Solar Homes (SASH) Program. MASH/SASH were financed using 10 percent of the overall $2.2 billion budget from the ratepayer-funded California Solar Initiative. The MASH program provides fixed, up-front, capacity-based incentives for qualifying solar energy systems on affordable multifamily dwellings. The goals of the MASH program are to:

  • Stimulate the adoption of solar power in the affordable housing sector;
  • Improve energy utilization and overall quality of affordable housing through the application of solar and energy efficiency technologies;
  • Decrease electricity use and costs without increasing monthly household expenses for affordable housing building occupants;
  • Increase awareness and appreciation of the benefits of solar among affordable housing occupants and developers;
  • Maximize the overall benefit to ratepayers;
  • Enroll eligible participants in the Energy Savings Assistance (ESA) program; and
  • Provide job training and employment opportunities in the solar energy and energy efficiency sectors of the economy.


Assembly Bill 217 (Bradford, 2013) extended the funding for MASH/SASH until 2021 or until incentives are encumbered, whichever occurs first. Under AB 217, the extended MASH Program includes new requirements for workforce development and energy efficiency starting in July 2015. A higher MASH incentive is available for projects that offset tenant energy use and provide direct tenant benefit, as opposed to a lower incentive for projects that only offset common load and typically benefit the building owner/operator.

California’s Virtual Net Energy Metering (VNM) program was piloted in MASH as a mechanism to provide direct tenant benefit. VNM allows for energy credits to be allocated among individual units as well as to common area load. Even with VNM,  it can be challenging to pass on a net monthly benefit to participating households that are in HUD subsidized housing due to the utility allowance structure. In HUD subsidized housing, rent plus utilities paid by tenants is adjusted to total less than 30 percent of their income. In some cases, the proportion of rent paid by the tenant will increase when utility costs decrease, rendering no net financial benefit to the household at the end of the month.

In 2015, Assembly Bill 693 (Eggman, 2015) established a new Multifamily Affordable Housing Solar Roofs Program (MAHSRP) to extend low-income multifamily solar options beyond the existing MASH program. Similar to MASH, the MAHSRP uses up-front rebates to reduce the cost of installing solar, but requires that the systems provide direct economic benefits to tenants. It is funded by the California Climate Investments fund (cap-and-trade revenues). The Multifamily Affordable Housing Solar Roofs Program – the largest dollar investment for low-income multifamily solar to date – is being implemented starting in 2016 with California Public Utilities Commission oversight. The program will be up and running no later than June 30, 2017 and will provide incentives up to December 31, 2030 for qualified deed-restricted multifamily properties.   

In addition, the California Department of Community Services and Development received an allocation of California Climate Investments funding (revenue from the state’s cap-and-trade program) for energy efficiency and renewable energy benefits to populations located within Disadvantaged Communities (DAC), of which $24 million has been committed to large multifamily properties. The Low-Income Weatherization Program – Large Multifamily (LIWP-LMF) brings together energy efficiency, solar thermal, and solar PV upgrade opportunities under a single program offering to support owners and residents in lowering utility costs, saving energy and reducing greenhouse gas emissions. Incentives cover approximately 30-80 percent of energy efficiency upgrades and 50-100 percent of solar installations.