Residential Solar

Understand Your Solar Options and Financing

Use CPAU's Solar Cost Estimator Tool on MyCPAU to get an estimate of savings you could realize by installing a rooftop solar system and to compare your solar financing options side by side. Results are based on your rooftop characteristics, your electricity use, CPAU electricity rates and available tax credits and rebates. Please sign into or create a MyCPAU account to use the Solar Cost Estimator Tool.

Evaluate Your Electricity Needs

Installing rooftop solar is a big investment. When sizing your system, it's important to think about how your electricity needs may change over time. CPAU's Home Efficiency Genie offers free phone-based advice on topics that impact your electricity needs, like home efficiency and electrification upgrades such as EV charging stations and new technologies for space and water heating with high-efficiency electric appliances. Call the Genie at (650) 713-3411.

The City also has online programs and resources for electric vehicles and heat pump water heaters.

Find a Solar Contractor

The City of Palo Alto Utilities (CPAU) recommends that you get at least three bids from experienced contractors, all with the same project specifications. Ask friends and utilize neighborhood networks to find out which solar contractors have experience installing systems in Palo Alto.

Selecting the right contractor is one of the most important decisions you make during the rooftop solar installation process.  Here are some tips and resources to help you find, compare, and select the right contractor for your project. 

Select, Sign and Install

Once you sign your solar contract, your solar contractor will guide you through the installation process. Most solar contractors manage the City's solar permitting process for their customers. After your system passes final inspection and you have permission to operate, your utility bill will reflect that you are a solar customer.

The City of Palo Alto requires all customers installing solar PV systems within City limits to apply for a PV Permit and receive Final Interconnection Approval (also known as “Permission to Operate”).

The City of Palo Alto Utilities (CPAU) is the municipal utility that oversees Net Energy Metering billing and Interconnection agreements, while the City of Palo Alto Building Department processes PV permits and issues final PV system approvals.

City of Palo Alto Utilities Programs & Services

Contact for: Inquiries relating to Net Energy Metering billing and agreements
Phone: (650) 329-2241
Email: PVPartners@cityofpaloalto.org

City of Palo Alto Building Department

Contact for: PV Permitting, Interconnection Approval
Phone: (650) 329-2496
Email: buildingpermits@cityofpaloalto.org

Learn More about PV Permitting

A standard grid-tied rooftop solar system will not provide electric power to your home in the case of a power outage. All grid-tied solar systems are required to disconnect from the grid during a power outage. This is so the “mini power plant” on your roof doesn't feed electricity back into the grid during an outage, which would endanger utility workers who are repairing the utility wires.

Rooftop solar with a battery can provide back-up power during an outage if the battery is wired properly. A battery storage system can allow you to capture unused power from your solar system and draw on that power during an outage event. Any solar and/or backup power systems must have a manual disconnect switch so that utility workers can disconnect the home from the grid in order to repair utility lines safely. Customers planning on installing a backup power system can learn more about Palo Alto battery storage permitting and inspection requirements by reviewing the Energy Storage System Permitting Checklist(PDF, 1MB). If you want to set up your battery storage system to function during an outage, be sure that your installer follows the appropriate requirements laid out in the permitting checklist.

Often, homes with battery storage will install a critical-loads subpanel because their backup power system was not sized to power the entire house but only the essential appliances, such as lights and refrigerators. The subpanel allows these critical loads to be isolated and the backup power supplied to only these loads.

*Specialized islanding solar inverters are also available, which can enable solar panel function in an outage without a battery. Islanding inverters can generally only provide reliable power equal to about a third of the home’s solar capacity, so a critical-loads subpanel would still help provide the best customer experience.

**Limited backup power can also be supplied by a solar generator, which can be used to power a few essential appliances, such as medical equipment, during an outage. These generators work by charging a portable battery with a small, portable array of solar panels.

1. Solar Panels - Convert sunlight into direct current (DC) electricity.
2. Solar Inverter - Converts electricity generated by solar panels from DC to alternating current (AC). Without a complementary battery storage system, this inverter will cut off solar energy production in the event of an outage.
3. Electric Subpanel - A smaller service panel that is connected to only essential appliances (critical load). During a power outage, backup power will only serve the critical load.
4. Battery Storage - Stores energy that can be used to supply backup power if an outage occurs. The battery stores DC power, so an inverter is required to charge or discharge energy. Some inverters may be built into the battery storage unit, while others may be separate. If the battery system is set up to supply backup power, the battery will also communicate with an automatic transfer switch to shut off the connection to the grid during a power outage. This allows the solar and battery system to continue operating to power critical loads as an energy “island”.
5. Main Electric Panel - This service panel connects to the non-critical loads in the home. Most battery systems do not have adequate capacity to meet both critical and non-critical loads during a power outage.
6. AC Disconnect - Allows utility workers to ensure that none of the energy generated by the customer can energize the grid while they are working.
7. Electric Meter - Measures the flow of electricity between the home and the electric grid.
8. Electric Grid - Delivers electricity to Palo Alto customers.

Once your solar system is installed and you have permission to operate, you  will be served as a CPAU NEM 2 customer. You will see a line item labeled "EEC-1 Solar Export Credit" in the “ELECTRIC” section of your utility bill on page 2. The dollar value displayed in that line item is negative because it is a credit that CPAU subtracts from the total of your electric charges. 

Free Energy Advice - When sizing your system, it's important to think about how your electricity needs may change over time. CPAU's Home Efficiency Genie offers free phone-based advice on topics that impact your electricity needs, like home efficiency and electrification upgrades such as EV charging stations and new technologies for space and water heating with high-efficiency electric appliances. Call the Genie at (650) 713-3411. 

Federal Tax Credits - Take advantage of the 30% Federal Renewable Energy Tax Credit for solar and battery storage systems installed by December 31, 2032. The tax credit drops to 26% for systems installed by December 31, 2033, and to 22% for systems installed by December 31, 2034. The tax credit expires for systems installed after December 31, 2034.

Find Ways to Save Energy and Water – CPAU energy and water programs and rebates can help you save money and increase the comfort of your home. Learn more at cityopaloalto.org/waystosave

Heat Pump Water Heater Rebate – Pairing an electric heat pump water heater (HPWH) with solar could reduce the cost to run the HPWH compared to running it without solar. Apply online for a heat pump water heater rebate of up to $2,300