The California Energy Commission (CEC) adopted the 2022 California Energy Code (California Code of Regulations, Title 24, Part 6, and Associated Administrative Regulations in Part 1, as well as associated Reference Appendices) that went into effect on January 1, 2023. Reference Appendices, Joint Appendix JA11.4.1 requires that solar assessment tools be certified by the CEC Executive Director according to the following requirements:
(1) The solar assessment tool shall calculate the annual solar access percentage of each individual solar array and a weighted average of the photovoltaic (PV) system as a whole. The calculation shall include all known obstructions, including any tree that is planted on the building lot or neighboring lots or planned to be planted as part of landscaping for the building.
(2) The solar assessment tool shall not include horizon shading in the calculation by default.
(3) The solar assessment tool shall produce a shade report with a summary of the PV system, including the address of the project, individual array panel count, orientation, annual solar access percentage, and a weighted average of the PV system as a whole.
(4) If the solar assessment tool model shading condition is based on satellite or aerial images, the annual solar access percentage values shall be comparable to on-site measurements, and documentation shall be provided to CEC as proof.
On July 7, 2025, Solesca Energy, Inc. submitted a request to the CEC to add their Solesca solar design & proposal tool to the CEC’s list of approved solar assessment tools. CEC Staff reviewed the application and the supporting documentation and determined that the Solesca assessment tool satisfies all applicable requirements of solar assessment tools listed in Reference Appendices, Joint Appendix JA11.4.1. Staff recommends that the Executive Director certify the Solesca solar assessment tool for the 2022 Energy Code.
