NEM 3.0 Explained: Why California Solar Without a Battery No Longer Makes Sense
NEM 3.0 Explained: Why California Solar Without a Battery No Longer Makes Sense
If you installed solar in California in 2022 and your neighbor installed in 2024, you're operating under fundamentally different economics — even if you have identical panels on identical roofs.
That's not a quirk. It's policy. In December 2022, the California Public Utilities Commission (CPUC) issued Decision 22-12-056, which replaced the long-standing NEM 2.0 net metering structure with a new framework called the Net Billing Tariff (NBT) — what most people call NEM 3.0. It took effect April 15, 2023, and it changed the math on residential solar in a way most installer marketing still soft-pedals.
Here's what actually happened, and what it means if you're shopping for solar in California today.
TL;DR
Solar exports under NEM 3.0 are credited at "avoided cost" rates — averaging around $0.08/kWh, down from roughly $0.30/kWh under NEM 2.0. That's a ~75% reduction.
You still pay full retail rate ($0.30–$0.50+/kWh) when you import from the grid. Solar-only systems get crushed by this gap.
Batteries fix it by letting you self-consume your own production instead of selling cheap and buying expensive. Storage attachment on new CA solar has surged from ~11% to over 50%+.
Existing NEM 2.0 customers are grandfathered for 20 years. New shoppers should not expect those terms.
What NEM 3.0 Actually Is
NEM 3.0 — officially the Net Billing Tariff or "Solar Billing Plan" — is the third version of California's solar compensation policy for residential customers in PG&E, SCE, and SDG&E territory. (Municipal utilities like LADWP and SMUD operate under separate rules.)
The mechanic that matters: under NEM 2.0, when your solar panels exported power to the grid, you received credit at the same rate you'd pay to import power. A near-perfect 1-for-1 swap. Under NEM 3.0, exports are credited based on the CPUC's Avoided Cost Calculator (ACC) — a model of what utilities would otherwise pay to procure that power on the wholesale market.
In practice, that means your exported solar power is credited at one rate, and the power you import from the grid is charged at a much higher rate. The two numbers used to be the same. They're not anymore.
[Source: CPUC, Net Energy Metering and Net Billing]
What Changed: The Export Rate
This is the part that matters and the part most installer content avoids quantifying.
Under NEM 2.0, exports were credited at retail rates — typically $0.30–$0.35/kWh, depending on your utility and time of use.
Under NEM 3.0, exports are credited at avoided-cost rates from the ACC. These rates aren't flat — they vary by hour, by month, and by weekday vs. weekend. There are 576 possible rate combinations across the year. Most of those combinations sit in the $0.05–$0.08/kWh range. A handful of hours — late summer evenings (August through October, roughly 4 PM to 9 PM) when the grid is most stressed — produce export values that can spike well above retail. But these high-value hours are exactly when the sun is setting and solar production is minimal.
Average export compensation under NEM 3.0 is roughly $0.08/kWh, compared to $0.30+/kWh under NEM 2.0. Most homeowners, most of the time, see a 75% reduction in export credits.
Here's the asymmetry that breaks solar-only economics:
NEM 2.0 | NEM 3.0 | |
|---|---|---|
Export credit (avg.) | ~$0.30/kWh | ~$0.08/kWh |
Import cost (avg.) | ~$0.30/kWh | $0.30–$0.50+/kWh |
Effective gap | ~$0/kWh | ~$0.22–$0.42/kWh |
You sell at avoided cost. You buy at retail. That gap is the entire problem.
Why This Destroys Solar-Only Economics
Solar production and household consumption don't happen at the same time. Panels produce most of their power between roughly 9 AM and 4 PM, peaking around midday. Homes use most of their power before 9 AM and after 4 PM — when people are home, cooking, running AC, doing laundry.
Under NEM 2.0, the timing mismatch didn't matter. Your panels exported at $0.30 during the day; you imported at $0.30 in the evening. The grid functioned as a free battery.
Under NEM 3.0, you're exporting midday solar at $0.05–$0.08 and re-buying it at $0.30–$0.50 in the evening. You're effectively selling power back to the utility at a steep discount and then buying it back at full retail markup. The economics break.
This is why the CPUC's own framing of NEM 3.0 explicitly assumed that going forward, residential solar would pair with battery storage. The policy is designed to push the market in that direction — and the market has responded.
Why Storage Fixes It
A home battery turns the timing mismatch from a liability into an asset.
Instead of exporting your midday solar production at $0.08/kWh, you store it. In the evening — when grid power costs $0.30–$0.50/kWh — you discharge the battery and use your own stored solar power. You've avoided buying expensive grid power, which is mathematically equivalent to "saving" $0.30–$0.50/kWh.
The arithmetic flips:
Solar only, NEM 3.0: Export credit ~$0.08/kWh
Solar + storage, NEM 3.0: Self-consumption value ~$0.30–$0.50/kWh
That's roughly a 4-5x value difference per kWh between exporting and self-consuming. Battery storage isn't a nice-to-have under NEM 3.0 — it's the entire investment thesis.
The market has noticed. Battery attachment rates on new California residential solar surged from around 11% pre-NEM 3.0 to over 50% by 2024, and the trend is still climbing.
Five Reasons Going Solar Without a Battery Just Doesn't Pencil
The full case for why solar+storage is now the only configuration that makes sense in California:
1. Export credits dropped roughly 75%. Under NEM 2.0 you sold midday surplus at retail. Under NEM 3.0 you sell at a fraction of retail. The "free battery" model the grid used to provide is gone.
2. California utility rates keep climbing. PG&E's rates have risen sharply over the past several years and continue to rise. SCE and SDG&E are on similar trajectories. As retail rates go up, the gap between export credit and import cost widens — making self-consumption (battery storage) more valuable, not less.
3. Time-of-use rate structures punish solar's natural pattern. New solar customers under NEM 3.0 are required to enroll in highly differentiated TOU rate plans. Peak rates (4 PM–9 PM) can run $0.45–$0.60/kWh, while off-peak rates (the middle of the day, when your panels produce most) are much lower. This is the inverse of when solar produces. Without storage to shift production into peak hours, you're producing power when it's worth the least.
4. The federal ITC equation has changed. Under the One Big Beautiful Bill Act passed in 2025, the residential clean energy credit (Section 25D) for customer-owned solar installations expired at year-end 2025. Cash and loan customers who installed in 2026 or later no longer receive the 30% federal tax credit. However, third-party-owned systems (PPAs and leases) remain eligible for the commercial ITC under separate provisions, and battery storage continues to qualify when paired with solar. This shifts the financial advantage toward PPA structures and toward solar+storage configurations specifically.
5. Grid reliability is getting worse, not better. California's Public Safety Power Shutoffs (PSPS), wildfire-related outages, and aging grid infrastructure mean that battery storage now delivers real resilience value beyond the bill math. A solar-only system shuts off during a grid outage (federal anti-islanding requirements). A solar+storage system keeps your home running. In a state where multi-day outages are no longer rare, that resilience is increasingly worth paying for.
See What This Looks Like for Your Address
The actual numbers depend on your specific utility, your TOU schedule, your usage pattern, and your roof. A general explanation of NEM 3.0 only gets you so far — the meaningful number is what your specific home would produce, store, and offset.
PowerGuard offers $0-down PPAs that include solar and battery storage as a single integrated system. A 20-minute consultation will model your specific bill under NEM 3.0 with and without storage, and show you what monthly cost looks like for your home. See your NEM 3.0 numbers.
What About NEM 2.0 Grandfathering?
If you already have solar in California and your system was interconnected before April 15, 2023, you're grandfathered under your existing NEM tariff (NEM 1.0 or NEM 2.0) for 20 years from your Permission to Operate (PTO) date. Your export credits remain at retail rate.
A few important nuances:
Adding a battery to an existing NEM 2.0 system typically does not break grandfathering, as long as you don't increase your system size by more than 10% or 1 kW (whichever is greater). You can enhance your system without losing favorable rates.
Significantly upsizing your panel array can trigger a switch to NEM 3.0. If you're considering an expansion, model both scenarios before committing.
Grandfathering transfers when you sell your home. The new owner inherits the remaining years of your grandfathered status — a non-trivial selling point.
If you're not sure which tariff applies to you, your most recent utility bill will indicate it.
Common Misconceptions
A few things you'll hear in the wild that aren't accurate:
"Solar is dead in California." No. Solar paired with storage still produces strong long-term economics — often better total returns over 25 years than NEM 2.0 solar-only ever did, because rate inflation has accelerated. What's dead is the simple solar-only payback story. The replacement story (solar+storage) is just less catchy.
"I should wait for the rules to change back." They aren't changing back. The CPUC has signaled clear support for the avoided-cost framework, and the underlying logic — that the grid value of midday solar has fallen as midday solar oversupplies the grid — is structural, not political. Waiting costs you money in utility bills you didn't have to pay.
"I'll just add a battery later." Possible, but typically more expensive than installing solar and storage together. Integrated installations qualify for combined permitting, shared inverter capacity, and often better PPA terms. Retrofit batteries also require a separate truck roll, separate inspection, and sometimes electrical panel upgrades that wouldn't be necessary if installed alongside solar.
"My system is grandfathered, so I should max it out now." Be careful. Going more than 10–15% over your historical usage on a NEM 2.0 system can trigger reclassification to NEM 3.0 for the entire system in some cases. Talk to your installer before significantly oversizing.
The Honest Payback Math Under NEM 3.0
Specific dollar payback varies enormously based on your utility, your usage pattern, your roof, your battery sizing, and which financing structure you choose. The honest framing:
A well-sized solar+storage system in California today typically produces meaningful monthly savings against your existing utility bill, with the savings growing over time as utility rates continue to rise. The case for solar+storage rests on three things working together: avoiding peak-hour grid charges, capturing federal incentives that still apply to PPA structures and battery storage, and providing resilience during outages.
The case against doing nothing is that California utility rates have outpaced inflation for years and are forecast to keep rising. Every month you delay is a month at full utility rates with no offset.
PowerGuard's PPA structure means you pay for the solar power you use, not for the equipment. The PPA includes a pre-set annual price escalator — which is intentionally set below the historical rate of California utility increases, so the gap between your PPA rate and the utility rate widens in your favor over time. We'll walk through your specific numbers in a consultation.
FAQ
What is NEM 3.0 vs NEM 2.0? NEM 2.0 credited solar exports at near-retail rates (~$0.30/kWh). NEM 3.0 — officially the Net Billing Tariff — credits exports at avoided-cost rates determined hourly by the CPUC's Avoided Cost Calculator, averaging ~$0.08/kWh. NEM 3.0 took effect April 15, 2023, for new residential solar customers in PG&E, SCE, and SDG&E territory.
How much do solar exports pay under NEM 3.0? Most exports are credited in the $0.05–$0.08/kWh range, with rare high-value hours during late-summer evenings (4 PM–9 PM, August–October) where rates can spike. Average annual export value is around $0.08/kWh.
Do I need a battery to go solar in California? Technically no — you can still install solar-only systems. Practically, the math no longer works without storage. The 4-5x value difference between self-consuming your power vs. exporting it makes battery storage essentially required for the system to pencil out.
Will my existing solar system change to NEM 3.0? No, if your system was interconnected before April 15, 2023. You're grandfathered under NEM 2.0 (or NEM 1.0) for 20 years from your PTO date. The grandfathering transfers if you sell your home.
Is solar still worth it in California? Yes — but only as solar+storage, and only if you understand what you're buying. Standalone solar payback under NEM 3.0 is significantly worse than under NEM 2.0. Solar+storage payback is competitive with NEM 2.0 solar-only and often better over a 20+ year horizon, given the trajectory of California utility rates.
The Bottom Line
NEM 3.0 didn't kill California solar. It killed solar-only. The replacement — solar paired with battery storage — produces a different economic story than the one homeowners signed up for under NEM 2.0, but for the right home, with the right sizing and the right financing, it produces a better one.
The wrong move is to install solar-only in California today and assume the math still works the way it did in 2021. It doesn't.
If you want to see what the actual numbers look like for your specific home, address, and utility, that's a 20-minute conversation. PowerGuard's PPA includes solar and battery storage as a single $0-down package, and we'll show you the bill modeling — NEM 3.0 export rates, TOU schedule, monthly cost — before you commit to anything. Get your custom NEM 3.0 estimate
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