NEM 3.0 California Solar + Battery Guide: What Changed and Why Batteries Are Now Essential

What Is NEM 3.0 and What Changed from NEM 2.0?

In April 2023, California's Public Utilities Commission (CPUC) replaced Net Energy Metering 2.0 (NEM 2.0) with a new framework officially called the Net Billing Tariff (NBT) — commonly called NEM 3.0. For homeowners who received solar interconnection approval before April 15, 2023, existing systems remain grandfathered on NEM 2.0 for up to 20 years. For anyone who applied after that date, NEM 3.0 is the new reality.^[1]

The core difference: solar export rates dropped approximately 75%.

Under NEM 2.0, utilities credited excess solar sent to the grid at the full retail electricity rate — typically $0.28–$0.35/kWh for most California customers. Under NEM 3.0, export rates are set by an "Avoided Cost Calculator" (ACC) that prices solar exports near wholesale. In 2025–2026, average NEM 3.0 export rates run roughly $0.04–$0.08/kWh — a fraction of what homeowners earned before.^[2]

The practical impact: A 6 kW solar system that exported 10 kWh of excess power per day would earn approximately $2.80–$3.50/day in NEM 2.0 bill credits. Under NEM 3.0, those same exports earn $0.40–$0.80/day. Annualized, that's a difference of $800–$1,000/year in lost export value.

That is why batteries have changed from a nice-to-have to a near-essential component of California solar systems under NEM 3.0.

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

Feature	NEM 2.0	NEM 3.0 (Net Billing Tariff)
Export credit rate	Full retail (~$0.30–$0.35/kWh)	Avoided cost (~$0.04–$0.08/kWh)
Battery required?	Optional	Strongly recommended
Grandfathering period	20 years from interconnection	N/A (current tariff)
Best strategy	Export freely, collect full credits	Store solar, discharge during peak hours
Annual export value (10 kWh/day)	~$1,095–$1,277/year	~$146–$292/year

Why Batteries Are Now the Difference-Maker: TOU Shifting

Under NEM 2.0, the grid acted as a free battery — excess solar earned full-value credits that offset future grid consumption at any hour. NEM 3.0 eliminates that arbitrage.

The new winning strategy is time-of-use (TOU) shifting: store excess solar in a battery during low-rate daytime hours, then discharge during the evening peak window (typically 4–9 PM), when California TOU electricity rates spike to $0.40–$0.55/kWh on most utility rate plans.^[3]

The economics now strongly favor batteries:

Strategy	Value per 10 kWh	Annual value
NEM 2.0 — export to grid	~$0.32/kWh	~$1,168/year
NEM 3.0 — export to grid	~$0.06/kWh	~$219/year
NEM 3.0 + battery (TOU shift)	~$0.45/kWh avoided peak	~$1,643/year

A 10 kWh battery storing solar and discharging during peak hours can save a California homeowner $1,400–$1,800/year — more than either NEM 2.0 or NEM 3.0 export-only. Batteries don't just add value under NEM 3.0; they restore the value that the export rate cut removed.

Use the EnergyScout SGIP & battery incentive finder to see what battery storage would save in your zip code.

How to Stack the SGIP Rebate With the Federal ITC for ~40% Off

The strong economic case for batteries is made even stronger by two major incentive programs that California homeowners can stack:

Federal Investment Tax Credit (ITC) — 30%

The Inflation Reduction Act's 30% Residential Clean Energy Credit applies to battery storage installed with solar (or as a standalone battery for systems installed after 2023). For a $15,000 installed battery (e.g., one Tesla Powerwall 3), that's a $4,500 federal tax credit.^[4]

California SGIP Rebate — up to $1,000/kWh

The Self-Generation Incentive Program (SGIP) pays California homeowners a per-kWh rebate for battery installation. Rebate levels depend on your eligibility tier:^[5]

• General Market: ~$150–$200/kWh — available to all PG&E, SCE, SDG&E, and SoCalGas customers. A 13.5 kWh Powerwall 3 earns ~$2,025–$2,700.
• Equity: ~$850/kWh — for households enrolled in income-qualified programs (CARE, FERA, Medical Baseline).
• Equity Resiliency: ~$1,000/kWh — for customers in Tier 2–3 High Fire Threat Districts or with qualifying medical conditions. Does not require solar pairing.

Combined stack example (General Market tier):

Item	Amount
Powerwall 3 installed cost	~$15,000
Federal ITC (30%)	–$4,500
SGIP General Market rebate (~$150/kWh × 13.5 kWh)	–$2,025
Net effective cost	~$8,475 (~44% off)

For Equity Resiliency households, the SGIP rebate alone can reach ~$13,500 for a single Powerwall — before the federal ITC is applied. See our California SGIP Battery Rebate Guide for the full application process, or browse the complete California incentive guide for every available program.

Real-World Example: 6 kW Solar + 10 kWh Battery in San Diego

Let's run the numbers for a typical San Diego homeowner who went solar under NEM 3.0 in 2024.

System specs:

• 6 kW solar array (18 × 335W panels)
• 10 kWh battery (2 × Enphase IQ Battery 5P)
• SDG&E TOU-DR-1 rate plan (peak: ~$0.52/kWh at 4–9 PM, off-peak: ~$0.30/kWh)

Solar generation: San Diego averages 5.5 peak sun hours/day. A 6 kW system produces roughly 33 kWh/day in summer and 20 kWh/day in winter — averaging ~26 kWh/day annually.^[6]

Without a battery (NEM 3.0 only)

Solar covers 20 kWh during daytime. The home pulls 5 kWh from the grid during peak hours (4–9 PM) at $0.52/kWh. Excess daytime solar (6 kWh) is exported at $0.06/kWh.

• Daily peak grid cost: ~$2.60 (5 kWh × $0.52)
• Daily export credit: ~$0.36 (6 kWh × $0.06)
• Net annual grid bill: ~$816/year

With a 10 kWh battery (TOU shifting)

The battery charges from solar midday and discharges during 4–9 PM peak, eliminating ~5 kWh of peak grid purchases.

• Daily peak grid cost eliminated: ~$2.60 saved
• Annual incremental savings vs. solar-only: ~$950/year
• Battery installed cost: ~$10,000
• Federal ITC (30%): –$3,000
• SGIP General Market (~$150/kWh × 10 kWh): –$1,500
• Net battery cost after incentives: ~$5,500
• Simple payback on battery: ~5.8 years
• 15-year net value added: ~$8,750

Under NEM 3.0, the battery pays back faster than it would have under NEM 2.0 — because the cost of not shifting TOU peaks is now so high.

Is Solar Still Worth It in California Under NEM 3.0?

Yes — but the calculus has changed. Solar alone under NEM 3.0 still reduces electricity bills significantly, but the return is lower than under NEM 2.0. The addition of a battery restores and often exceeds the economics of a NEM 2.0 solar-only system, especially for households with high TOU peak consumption.

The practical answer for most California homeowners in 2026: solar + battery is the optimal configuration. Solar-only under NEM 3.0 is better than nothing, but leaves significant value on the table compared to what SGIP, ITC, and TOU shifting can unlock together.

Use EnergyScout's battery incentive finder to calculate your net cost after SGIP and ITC, or explore all available incentives in the California incentive guide.