Net Metering in California: How It Works

Solar net energy metering in California (NEM 3.0) is a billing mechanism through which utility companies compensate customers (via credits on their electric bill) for electricity their residential solar systems send to the grid. NEM can make solar more affordable, but some state NEM policies make it less beneficial.

California is one of those states; however, solar panels in California can still be worth it for homeowners. Understanding how net metering works in California can help you get the most out of your solar system.

How net metering has evolved in California

NEM in California has gone through three major versions:

California’s first NEM program was implemented in 1996. Under NEM 1.0, solar customers could sell their extra electricity back to the utility at the retail rate (the price at which the utility charged consumers for electricity), they could choose any electric rate plan the utility offered and they didn’t have to pay extra fees for connecting to the grid.

NEM 2.0 was introduced in 2016–2017. This version of NEM still compensated customers for excess power at the retail rate, though customers couldn’t offset 100% of the charges (some were “nonbypassable”). It also required solar customers to be on a time-of-use (TOU) rate plan in which the price of power depends on when it’s used, and it introduced an interconnection fee ^[0]

Officially called the Net Billing Tariff (NBT), NEM 3.0 is the current version of NEM, adopted by the California Public Utilities Commission (CPUC) in December 2022 and implemented in April 2023. The NBT cut the rate utilities pay to buy excess solar power by about 75% ^[0]

5 things to understand about net metering in California

These provisions affect many solar installations and related electric bills in California.

1. Low payment for your excess electricity. This is the biggest factor affecting NBT solar customers. Under the NBT, you are paid for the electricity you send back to the grid according to a complicated “avoided cost” formula that takes into account the value of that electricity to the grid at the time you send it to the grid. Your system will likely send excess electricity to the grid during the middle of the day, which is when lots of other people are also sending excess solar power to the grid. That means the utility will buy your electricity for a much lower rate than it would have under NEM 2.0.

2. Time-of-use (TOU) rate plan. Under TOU rates, what you pay for electricity depends on when you use it. The NBT requires solar customers to pay specific TOU rates that, compared with other TOU rates, are lower at off-peak use times and higher at peak times. That will further affect your electricity costs and solar savings. 

3. Nonbypassable charges. As the name suggests, solar customers pay these charges even if they generate enough extra power to offset them. Under the NBT, nonbypassable charges are based on all electricity you pull from the grid. 

4. Monthly billing, annual true-up. The utility keeps a running tally of whether the value of the power you’ve used from the grid is more than the value of the power you’ve sent to the grid. If you took more than you gave, you’ll get a bill from the utility; if you gave more than you took, the utility gives you a credit on your bill. This reconciliation exercise used to happen once a year; now it’s once a month. “Under NEM 2.0, residential customers of investor-owned utilities do not pay more than the roughly $10 minimum bill if they owe more than that at the end of a month. They pay the cumulative amount owed at their annual true-up date,” said Brad Heavner, policy director at the California Solar and Storage Association (CALSSA), in an email. “Under NBT, if customers owe an amount at the end of a month, they pay that full amount. This avoids surprise annual true-up bills.”

5. Solar system size limit. Under the NBT, customers can install enough solar to offset up to 150% of their electricity use. To do this, they must sign a statement acknowledging that they are getting more solar than they need to serve their rate of consumption, Heavner said. However, utilities have been inconsistent in implementing this, said Barry Cinnamon, CEO of California solar company Cinnamon Energy Systems, in an email. Be aware of size limits if you already have solar and want to add more, which might bump you from NEM 1.0 or NEM 2.0 to the NBT. “There are ways for customers to increase the size of their existing NEM 1.0 or NEM 2.0 system without triggering a change to the NBT,” Cinnamon said. “Contact your local installer for more information on these solar expansion possibilities.”

How to make California net metering (NEM 3.0) work for you

Even with the drawbacks of the NBT, solar may still make sense for your California home. Here’s how you can make NEM 3.0 work for you.

A solar battery can make a big difference in the cost-effectiveness of your solar under the NBT. Instead of sending excess electricity back to the grid at a low rate, you can store it in your battery and use it later. You can also avoid high TOU rates by charging the battery when you’re generating the most electricity, then using that electricity during expensive peak TOU hours.

For these reasons, many new solar customers in California are turning to batteries. According to the Energy Information Administration, the number of California solar customers installing batteries with their solar panels jumped from just over 20% in October 2023 to well over 50% in April 2024 ^[0]

Batteries are expensive, however. In California, the average cost is $7,706 after the 30% federal tax credit, according to EnergySage ^[0]

If you can, use energy when you’re generating the most solar or when rates are low. For example, do laundry in the middle of the day or charge an electric car after peak evening hours. If you work from home, you may already use more electricity during the day, when your system is generating the most.

Every two years, the CPUC updates the avoided cost calculator, which determines what the utility will pay consumers for their excess electricity.

“Customers lock in the currently calculated export rates for the next nine years,” Heavner said. “These numbers change each year, but you know what they are according to the current calculation of export rates. This lock-in will no longer be available to customers installing after 2028.”

Export rates have been coming down, Heavner said. They could also go up in the future, becoming more favorable to NBT customers, as the value of energy sent to the grid increases because of rising electricity demand.

“It is not clear how the utilities will change the NBT export rate,” Cinnamon said. “The original export rates were already effectively reduced by utilities, so I expect that these export rates will continue to change in the utilities’ favor.”

Solar panels usually last 20–30 years. Although the NBT lengthened the solar payback period (now nine years, by some estimates), you may still save money over time. In addition, rapidly rising electricity costs could shorten that payback period ^[0]