NEM 3.0 Explained: What California's Net Metering Change Actually Means for Temecula Solar

Adrian Marin|Independent Solar Advisor, Temecula CA

Helping Riverside County homeowners navigate SCE rates and solar options since 2020

On April 15, 2023, California changed the rules for every new solar customer in the state. The California Public Utilities Commission replaced NEM 2.0 with what they officially call the Net Billing Tariff, commonly known as NEM 3.0. The change was significant: export rates for excess solar electricity dropped from roughly retail prices of $0.30 to $0.40 per kWh to avoided-cost rates of approximately $0.04 to $0.08 per kWh. That is a cut of 75 to 90 percent in what the utility pays you for power you generate but do not use. If you went solar after that date or are considering solar now, the financial math is different from what your neighbor who installed in 2021 is experiencing. This guide explains exactly what changed, what it means in dollar terms for a Temecula home, and what the right strategy looks like under the new rules.

What NEM 2.0 Was and Why the CPUC Changed It

Net Energy Metering 2.0 operated on a simple premise: your solar panels produce electricity, your home uses what it needs, and whatever is left over flows to the grid. SCE credited you for that exported electricity at the same rate you would have paid to buy it back -- the retail rate. At the end of a 12-month period, SCE settled your account at a true-up date. If you exported more than you consumed over the year, the surplus was settled at a low avoided-cost rate. But throughout the year, monthly credits rolled forward and could offset future bills.

The economics were straightforward: every kilowatt-hour your panels produced was worth the same whether you consumed it immediately or sent it to the grid. A large system that significantly overproduced relative to consumption could bank credits all summer and use them to eliminate winter bills entirely. Payback periods of 5 to 7 years were common in the Inland Empire under NEM 2.0 at current SCE rates.

The CPUC argued that NEM 2.0 was too generous -- that retail-rate export credits effectively shifted grid maintenance costs onto non-solar ratepayers who still relied on the grid for all their electricity. They also argued that cheap export rates under NEM 2.0 did not create an incentive for solar customers to store energy and use it during the grid's highest-demand periods (late afternoon and evening), which would benefit the overall grid. NEM 3.0 was designed to fix both issues by paying export rates tied to the actual value of electricity to the grid at the moment of export, not the retail rate.

NEM 2.0 vs. NEM 3.0: Side-by-Side Comparison

The table below captures the key structural differences between the two programs. Every new solar customer who applied for interconnection after April 15, 2023 is on NEM 3.0 terms.

What the Rate Cut Means in Dollar Terms: A 10 kW System in Temecula

The difference between a $0.35/kWh export rate and a $0.06/kWh export rate is abstract until you run the numbers on a real system. Here is what the change looks like for a 10 kW solar system on a typical Temecula home with moderate daytime occupancy.

A 10 kW system in Temecula, with roughly 5.5 peak sun hours per day and 80% system efficiency, produces approximately 16,000 kilowatt-hours per year. A typical Temecula home with two working adults and no EV uses about 14,000 to 18,000 kWh per year. If the home is largely unoccupied during peak solar production hours (10am to 3pm on weekdays), a meaningful portion of that midday production gets exported rather than consumed. Call it 4,000 kWh exported per year on a 10 kW system with moderate daytime self-consumption.

Over a 25-year system life, that difference in export credit value -- $1,160 per year -- compounds to roughly $29,000 in reduced lifetime savings, before considering SCE rate increases. That is a real and meaningful reduction in the solar value proposition compared to what customers who installed before April 2023 are experiencing.

However, the 12,000 kWh per year that the same system produces and the home consumes directly is worth exactly as much under NEM 3.0 as under NEM 2.0. The solar electricity you consume avoids paying SCE rates that range from $0.25 to $0.55 per kWh depending on time of day. The direct consumption savings do not change. NEM 3.0 only affects the portion of production that leaves your home and flows to the grid.

Why Battery Storage Became Nearly Mandatory Under NEM 3.0 Math

The core mismatch under NEM 3.0 is timing. Solar panels produce the most electricity between 10am and 3pm. SCE charges the highest rates during the 4pm to 9pm peak window, when solar production is dropping toward zero. Without storage, your system is producing cheap electricity at the wrong time of day for maximum value.

A battery changes this completely. A 13.5 kWh battery such as the Tesla Powerwall 3, a 10 kWh Enphase IQ Battery 10T, or a Franklin WH10 charges during the midday solar surplus window at essentially zero cost. It then discharges during the 4pm to 9pm peak period, displacing electricity you would otherwise buy from SCE at peak TOU rates of $0.40 to $0.55 per kWh. The math on that arbitrage:

Adding winter months and shoulder seasons at lower rates, a 10-13 kWh battery system in Temecula typically generates $700 to $1,200 per year in additional savings compared to the same solar system without storage. At that rate, a $10,000 to $14,000 battery (after the 30% federal tax credit reduces it to $7,000 to $9,800) pays back in 7 to 10 years on the battery alone -- while also providing backup power during SCE outages.

Under NEM 2.0, adding a battery was a nice-to-have with a marginal financial return because retail-rate export credits already captured most of the value of excess production. Under NEM 3.0, the battery does not just add value -- it fundamentally rescues the financial case for solar by converting low-value exports into high-value self-consumption.

TOU Rates and the 4-9pm Peak: The NEM 3.0 Optimization Game

Every SCE solar customer under NEM 3.0 is on a Time-of-Use rate plan. The most common plan is TOU-D-4-9PM, which charges premium rates from 4pm to 9pm daily. Outside that window, rates are significantly lower. The rate structure looks approximately like this in summer 2026:

The optimization is clear: maximize self-consumption during the solar production window, fill the battery with any surplus, and live off the battery during the expensive 4-9pm window. For Temecula homeowners, the high air conditioning load from May through October naturally aligns with this strategy. Air conditioning runs heaviest in the early afternoon when solar is at peak production and the AC load is highest -- which means a large portion of your solar production is immediately consumed rather than exported. The inland heat that makes Temecula summers brutal actually works in your favor under NEM 3.0 self-consumption math.

Temecula Self-Consumption Advantage: Why Inland Heat Helps NEM 3.0 Math

Not all California solar markets are equal under NEM 3.0. A coastal home in San Diego or Santa Monica has mild temperatures and relatively low summer cooling loads. A solar system there might export 40 to 50 percent of its production on weekdays because the home does not need much electricity during the day. Under NEM 3.0, that exported power is worth almost nothing.

Temecula is different. Average high temperatures from June through September run 95 to 105 degrees Fahrenheit in the valley. Air conditioning accounts for 40 to 55 percent of summer electricity usage in the IE. A central AC system running during peak solar hours (10am to 3pm) consumes 3 to 5 kW continuously. A pool pump adds another 1 to 2 kW. A home with both a pool and central AC in Temecula can easily self-consume 80 to 90 percent of solar production on a summer weekday without any special effort or automation.

This high self-consumption rate is the inland homeowner's structural advantage under NEM 3.0. The electricity that stays in your home avoids SCE rates of $0.30 to $0.55 per kWh. Only the small fraction that escapes to the grid earns the low $0.04 to $0.08 avoided-cost rate. The more your home naturally consumes during solar production hours, the less the NEM 3.0 export rate cut actually matters to your bottom line.

Compare two California homeowners with the same 10 kW system: a San Diego coastal home that self-consumes 55% and a Temecula home that self-consumes 82%. The Temecula home exports roughly half the electricity of the coastal home. The NEM 3.0 export rate cut costs the Temecula homeowner proportionally less. Inland IE homeowners were the most economically damaged by NEM 2.0 bill increases over the last decade and are the least affected by NEM 3.0 relative to coastal markets.

NEM 2.0 Grandfathering: 9 Years and the Rules for Adding Panels or Battery

If you installed solar before April 15, 2023 on an SCE system, you are grandfathered on NEM 2.0 terms for 9 years from your original interconnection date. That means the customer who connected in January 2023 stays on NEM 2.0 retail-rate export credits until approximately January 2032. The customer who connected in 2018 transitions to whatever program is in effect in 2027.

The question many NEM 2.0 customers ask: can I add a battery without losing my grandfathered status? The answer is yes. Adding a battery storage system to an existing NEM 2.0 solar installation does not trigger a requirement to re-interconnect under NEM 3.0. SCE treats the battery as a separate piece of equipment and the solar system remains under its original interconnection agreement. This is one of the most valuable near-term opportunities for NEM 2.0 customers: add a battery now, stay on your grandfathered rate, and capture the peak-rate arbitrage value on top of your already-favorable export credits.

Adding more solar panels to an existing NEM 2.0 system is more complicated. SCE applies rules about the size of the addition relative to the original system. Small additions that bring total system capacity to within the bounds of the original interconnection agreement may be allowed without triggering NEM 3.0 re-interconnection, but larger expansions can push you onto the new tariff. If you are on NEM 2.0 and want to add panels, get a written determination from your installer and from SCE before signing anything. Losing NEM 2.0 grandfathering by adding a few extra panels is a costly mistake that cannot be undone.

Monthly True-Up vs. Annual True-Up: The Practical Cash Flow Difference

The shift from annual to monthly true-up under NEM 3.0 changes how you experience the financial cycle of solar ownership. Under NEM 2.0, SCE let you accumulate net metering credits month to month throughout the year. Summer solar surplus rolled forward and offset winter bills, creating a smoothing effect. Many NEM 2.0 customers paid near-zero SCE bills for most of the year and had one annual true-up in which they paid a relatively modest amount to settle the non-bypassable charges.

Under NEM 3.0, the monthly settlement means credits expire at the end of each billing cycle. If your panels generate more electricity than you consume in July, you earn export credits at approximately $0.06 per kWh for that month. Those credits are applied to your July bill and then disappear. They do not carry forward to reduce your August bill or your January bill. Each month stands on its own.

In practical terms, NEM 3.0 customers should expect a different bill pattern than NEM 2.0 customers. Summer months with high production and high AC load will typically result in low or zero bills because most production is self-consumed. Winter months with lower production and higher heating or lighting loads may result in higher bills because the summer surplus cannot offset them. Right-sizing your system and battery for self-consumption rather than for maximum annual export becomes the new design philosophy.

Payback Period Comparison: NEM 2.0 vs. NEM 3.0 for a Temecula 10 kW System

The payback period for solar changed under NEM 3.0, but not as dramatically as the export rate cut alone would suggest, because most of the financial return from solar comes from self-consumed electricity, not from export credits. Here is a realistic comparison for a 10 kW system at a Temecula home using 2026 SCE rates and the 30% federal tax credit.

Estimates based on 10 kW system, 16,000 kWh/year production, 78% self-consumption rate, SCE rates averaging $0.34/kWh blended and increasing 6% annually, 30% federal ITC applied. Battery scenario uses 13.5 kWh capacity at $13,000 before ITC. Actual results vary by home size, usage, and occupancy patterns.

The key insight from the table: a NEM 3.0 system with a battery reaches nearly the same 25-year savings as a NEM 2.0 system without a battery, because the battery captures peak-rate value that compensates for the loss in export credits. The upfront cost is higher, but the savings trajectory converges over the 25-year system life as SCE rates continue to increase.

Is Solar Still Worth It Under NEM 3.0? The Honest Answer

Solar is still worth it under NEM 3.0 in Temecula, but the financial case is now built on self-consumption rather than export credits. The homeowner who installs a correctly sized system with a battery, has meaningful daytime electricity loads (air conditioning, pool pump, EV charging), and plans to stay in the home for 10 or more years will still see strong financial returns.

The homeowner who should think more carefully: someone in a home they plan to sell in 3 to 5 years, who has very low electricity usage (under 10,000 kWh per year), or whose home has severe shading limitations that reduce production below the point where self-consumption economics work. For those edge cases, the NEM 3.0 math is harder to justify, and a smaller system or a PPA/lease structure might make more sense.

SCE rates have increased at an average of 5 to 7 percent per year over the last decade and show no sign of slowing. The proposed rate increases through 2028 suggest SCE customers without solar will continue seeing their bills rise significantly. Solar's value is not static -- it increases every year as the grid electricity it displaces becomes more expensive. A system installed today under NEM 3.0 that has a 9-year payback at current rates will likely look like a 7 to 8 year payback when measured against actual SCE rates in years 3 through 9.

The federal solar tax credit is also still at 30% through 2032, after which it steps down. The incentive environment for 2026 is as good as it has been in years. Anyone who has been waiting on the sidelines since April 2023 thinking NEM 3.0 killed solar math has likely cost themselves 2 to 3 years of savings and risks missing the tail end of the 30% credit window.

Frequently Asked Questions About NEM 3.0