Solar on Multifamily Affordable Housing (SOMAH)

Solar on Multifamily Affordable Housing (SOMAH) program provides incentives for solar energy photovoltaic systems for multifamily affordable housing. Those interested in learning more about the SOMAH Program should visit the program's website:

Key Components of the SOMAH Program:

  • A budget up to $100 Million annually from the electric IOUs' Greenhouse Gas Auction Proceeds for this solar program
  • Incentive levels for customers range from $1.49 to $2.97 per AC Watt for load serving tenants and $0.56 to $1.02 per AC Watt for load serving common areas (10/30/21 through 10/01/22), depending on tax credit usage for the project, and step-down each year
  • Encourages solar system installations in California's disadvantaged communities across the state
  • Emphasizing the explicit goal that incented solar systems lower tenant energy bills
  • Develop, by December 31, 2030, at least 300 megawatts of installed solar generating capacity

Implementation of AB 693 to establish SOMAH

Assembly Bill (AB) 693 (Eggman, Chapter 582, 2015) provides financial incentives for the installation of solar energy photovoltaic systems on multifamily affordable housing properties throughout California.  The statute, among other things, prescribes criteria for participation in the incentive program; sets targets for installation of solar PV systems; identifies various required elements for the Program; and gives direction to the California Public Utilities Commission (CPUC) on the program administration.

In response to the legislation, the CPUC, in proceeding R.14-07-002, issued a Ruling to stakeholders seeking input on the design, implementation, eligibility and other programmatic issues for the new program.  Nearly 25 parties provided over a thousand pages of comments in response to the ruling.

In December 2017, the CPUC issued a decision, D.17-12-022, which outlines the program design for the SOMAH Program to incentivize solar systems. The Decision builds on many of the program successes and lessons learned from the California Solar Initiative Multifamily Affordable Solar Housing Program, which ends in 2021.

In March 2018, the CPUC's Energy Division selected via a competitive bidding process, a single, statewide program administrator team. The SOMAH Program Administrative team is comprised entirely of non-profit organizations: the Center for Sustainable Energy (CSE), GRID Alternatives (GRID), the Association for Energy Affordability (AEA), and the California Housing Partnership Corporation (CHPC). On July 1, 2019 SOMAH began accepting applications.

Applying for SOMAH Program Incentives

For information on how to apply for incentives in your area, please go the SOMAH Program website and select your utility provider under “Ready To Apply”:


Recent News for SOMAH

Upcoming Events for SOMAH Proceedings and Reports

  • There are no CPUC related upcoming events at this time.
  • SOMAH program event information can be found here:

Implementation Guidance

Energy Division IOU SOMAH Budget Guidance Memo

Solar on Multifamily Affordable Housing (SOMAH) - You Tube video

IOU SOMAH Semi-Annual Expense Report Template


SOMAH Information

Click on the link to go to the relevant section below.

 SOMAH Regulatory Proceeding Information

 SOMAH Program Information
 SOMAH Decisions, Rulings, and Advice Letters   SOMAH Program Website
 Net Energy Metering (NEM) Information  SOMAH Program Handbook
   SOMAH Program Semi-Annual Reports 
  SOMAH Joint-IOU Semi-Annual Reports
  SOMAH Evaluation Reports 


SOMAH Decisions, Rulings, and Advice Letters

The CPUC Rulemaking R.14-07-002 currently handles all issues related to the SOMAH Program.  Decisions and regulatory matters include:

  • Decision D.17-12-022 (December 2017) establishes the SOMAH program
  • Resolution E-4987 (April 2019) approves with modifications the SOMAH Program Handbook Program Implementation Plan in Compliance with Decision (D.)17-12-022. Adopted Program Implementation Plan (CSE 92-E-A/GRID 12-E-A) and Program Handbook (GRID 11-E-B). The Program Handbook has been updated since this initial filing.
  • Advice Letter 3285-E Disposition (April 2019). Disposes of San Diego Gas and Electric's advice letter that provides information regarding establishment of a Solar on Multifamily Affordable Housing Balancing Account (SOMAHBA) pursuant to D.17-12-022
  • Decision D.19-03-015 (April 2019) modifies D.17-12-022 providing flexibility in IOU administrative expenditures. It also outlines options regarding auditing or review of the SOMAH program and establishes co-funding and incentive agreement deadlines
  • Decision D.20-04-012 (April 2020). The decision determines revenues are available and that there is adequate participation and interest in SOMAH program, continuing authorization of allocation of funds to the SOMAH program through June 30, 2026
  • Resolution E-5054 (June 2020) The Resolution approves revisions to the SOMAH Program Handbook to limit participation of a photovoltaic (PV) project to either the SOMAH Program or the MASH Program
  • Disposition of CSE Advice Letter 133-E/133-E-A (April 2022) which approves SOMAH Program Handbook 5th Addition.
  • Decision (D.) 22-09-009 amended D.17-12-022, for the SOMAH forecast budgeting process the IOUs can propose to set aside their proportionate share of $100 million for SOMAH, if they adequately show that the IOUs' collective revenue will exceed $1 billion. 
  • CSE Advice Letter 138-E to update the SOMAH Handbook submitted on September 29, 2022, with substitute sheets provided on November 9, 2022, and December 14, 2022.

If you wish to receive notice of proceeding information the public can join the proceeding as “information only,” follow the instructions here.


IOU SOMAH Semi-Annual Administrative Expense Reports

Pursuant to D.19-03-015, the electric IOUs must jointly file and serve semi-annual reports detailing their administrative expenses incurred in support of the SOMAH Program for the preceding six full months and show cumulative totals. The revised Excel template (as of December 2021) for the IOUs is here.

  • January 21, 2023 Joint IOU Report (PDF, Excel)
  • July 21, 2022 Joint IOU Report  (PDF, Excel)
  • January 21, 2022 AMENDED Joint IOU Report (PDF, Excel)
  • July 21, 2021 Joint IOU Report (PDF, Excel)
  • January 21, 2021 AMENDED Joint IOU Report (PDF, Excel)
  • July 21, 2020 Joint IOU Report (PDF, Excel)
  • January 21, 2020 Joint IOU Report (PDF, Excel)
  • July 21, 2019 Joint IOU Report (PDF, Excel)


SOMAH Program Semi-Annual Progress and Expense Reports

Pursuant to Appendix B of D.17-12-022 the Program Administrator submits semi-annual reports to the Director of the Energy Division on progress of the SOMAH program. These reports are also available on California Distributed Generation Statistics.

  • July 30, 2022 Report can be downloaded (PDF, Excel)
  • January 31, 2022 Report can be downloaded (PDF, Excel)
  • July 30, 2021 Report can be downloaded (PDF, Excel)
  • January 1, 2021 Report can be downloaded (PDF, Excel)
  • July 30, 2020 Report can be downloaded  (PDF)
  • January 1, 2020 Report can be downloaded (PDF)

The most recent SOMAH Program Semi-Annual Expense Reports can also be downloaded on DG Stats here.


SOMAH Evaluation Reports

Pursuant to AB 693, D.17-12-022 and PU Code 2870(j)(1) and PU Code 913.8, Energy Division is directed to provide regular evaluations to the legislature of the SOMAH Program.

In 2022, Verdant Associates will begin the next 2023 Triennial SOMAH Program Evaluation to assess program impacts and progress on metrics and reaching program goals.

Evaluation reports:

Evaluation webinar slides:

  • Draft 2023 Triennial SOMAH Evaluation Research Plan Presentation
  • 2021 Draft Phase II Evaluation Report Webinar Slides can be located here.
  • 2020 Phase II SOMAH Process and Impact Assessment Draft Report Webinar Slides can be located here.
  • 2020 SOMAH Process and Impact Assessment Draft Report Webinar Slides can be located here.
  • 2020 SOMAH Process and Impact Assessment Draft Research Plan Public Webinar Slides can be located here.