MEMBERS-ONLY FACT SHEET
Compliance Requirements for “Solar Energy System
Supporting Information” Document

 Last Updated October 31, 2025

IMPORTANT UPDATE REGARDING USE OF PVWATTS IN SECTION 4, 'Estimated annual solar electricity generation’

The CSLB and CPUC have created a new Solar Energy System Supporting Information document that must be submitted as part of the interconnection application for all residential NEM and NBT systems effective November 1, 2025. It must be submitted in all IOU territories, including the small IOUs of Bear Valley Electric Service, Liberty Utilities, and PacifiCorp. It is not required in any municipal utility territory. No customer signature is required on the document. This document must be provided in addition to the Solar Energy System Disclosure. The CPUC and the CSLB do not explicitly state when the Solar Energy System Supporting Information document must be presented to the customer, but it is implied that it should be included with the contract. This document does not need to be provided when the solar is installed as a standard feature on new construction.

The Solar Energy System Supporting Information document has four sections:

1. Important Information for the Consumer

2. Installation Information

3. Information about the Agreement

4. Energy Savings

Handwritten entries in the document will not be accepted. Only typewritten and machine-readable forms are allowed. The information in the document should be consistent across all interconnection documents. Utilities will be checking for completion as part of their semiannual spot audits.

Section 1: Important Information about the Consumer

This section includes general consumer guidance about installing solar. Nothing is completed by the contractor.

Section 2: Installation Information

There are three fields that must be completed by the contractor in this section. The contractor must disclose whether or not a subcontractor will be used. If “yes” is selected, the document states that the name, license information and contact information for the subcontractor will be shared before the installation. If it is unknown, contractors have a reasonable argument to select either box, but CALSSA would recommend sharing information about the subcontractor ahead of time if one is ultimately used, regardless of how the box is checked. The disclosure then asks for the page numbers of the contract referencing warranty and service information.

Section 3: Information about the Agreement

This section contains information about whether the system is being purchased, and if so, whether a loan is used, or if it is a leased or PPA system.

For purchases, the guide asks for the total cost of the system or loan. If a loan is used, contractors must include the name of the lending company, the duration of the loan, monthly payments, and the interest rate.  

For leases and PPAs, the form should include the name of the financier, the duration of the lease or PPA, and the page number for information regarding transferring the lease or PPA to a new owner should the home be sold. For leases, contractors must disclose the total cost of the system, the monthly payment, and the escalator. For PPAs, contractors must disclose the price per kWh, the escalator, any upfront payment if applicable, and monthly payments if applicable.

Questions:

What about cases where the customer only finances part of the solar system cost (ex. $50,000 system and the customer pays $25,000 in cash and takes out a loan for $25,000)?
If there are loan payments, the monthly payment box should list what the customer is paying every month, not monthly loan payments that are averaged out by including the upfront payment.

What if the loan terms change over time? For example, what would we put down if the loan starts at $100 a month but increases to $150 a month after x years if the customer does not pay y dollars?
The goal is to ensure there are no surprises for the customer, so contractors should spell out as best they can the terms of the loan in the relevant section.  In this situation it could be done by, for example, putting “$100/month for two years; if no payment of y dollars at that time, payment increases to $150/month.”

What should we do for prepaid PPAs where a loan is used for the prepayment?
This can be conveyed in several ways:

1. The contractor could complete the “Upfront Payment” and “Monthly Payments” in the PPA Section and leave the escalator blank.

2. It is also acceptable to complete parts of both the Cash/Loan and PPA section. Contractors would put the upfront cost in the PPA section and the monthly payments and interest rates in the Cash/Loan section. Contractors can ignore the “complete one” instructions in this scenario.

What if the payment amounts differ depending on if it is paid with ACH?
It is recommended that you put both the ACH and non-ACH amounts if possible. 

Section 4: Energy Savings

The first part of this section covers the “Inputs and Assumptions” for the savings estimate and requires completing the following fields:

• Electricity usage for the past 12 months: This must be based on hourly interval data. If hourly interval data is not available, there is a separate field for the contractor to explain why it could not be obtained and to explain how the consumption estimate was derived.

• Estimated annual solar electricity generation: FOR SOLAR ONLY INSTALLATIONS, this figure must be calculated using the PVWatts Calculator tool only. FOR SOLAR + STORAGE INSTALLATIONS, this figure must be calculated using the calculator of your choice, not necessarily PV Watts.

• Battery capacity (if applicable)

• Battery minimum state of charge (if applicable)

• The customer’s current rate schedule and the post-install rate schedule

The next part of this section provides two different options: estimated bill savings for solar and storage and for solar only. Only one must be completed. All dollar savings estimates are for the first year only.

For the section on solar and storage savings, the contractor must complete a savings estimate maximizing the battery for bill savings, which is defined as, “battery is programmed to optimize bill savings by serving onsite load or exporting to the grid based on price signals.” There are two optional estimates that may be completed for “prioritizing self-consumption,” meaning the customer relies on self-generation as much as possible, and “programmed for home back-up,” meaning the customer keeps the battery at 100 percent state of charge for outages. The contractor must then disclose what calculator was used in determining the savings estimate. The document provides separate fields to complete for the name of the calculator used in either the solar and battery storage estimate or solar only savings estimate.

Note: Solar contractors may still present their own multi-year savings estimate in addition to the Solar Energy System Supporting Information document, but any escalator must be capped at the average rate of calculation that will be posted in the most recent consumer guide. Contractors must also retain all data used to inform the Solar Energy System Supporting Information document for twelve months.

Questions:

Do I need to complete the “Estimated annual solar electricity generation” section if I am adding a battery to a customer with an existing PV system?
Yes. In this situation, contractors should make best efforts to complete this section using a calculator of their choice based on the age and condition of the system.

Do I need to complete the “Estimated annual solar electricity generation” section if I am adding a battery to a customer without an existing PV system?
No.