My PG&E Bill Is $400/Month — How Much Solar Do I Actually Need in 2026?
- May 6
- 14 min read
Updated: May 7
A few years back, I was delivering inverter shipments to a contractor in Fresno — one of those weeks in July when the Central Valley hits 108°F before noon. The homeowner, a retired teacher, met me at the garage door holding her PG&E bill. $423. She'd already turned her thermostat up to 80°F. She wasn't being careless. She had a normal house with normal AC, and PG&E's summer rates had just eaten her fixed income.
She asked me the same question I've heard dozens of times since: how much solar do I need to cut this bill?
It's the right question — but the answer isn't as simple as dividing your bill by a panel's wattage. In 2026, with NEM 3.0 (Net Energy Metering 3.0 — the policy that determines how much PG&E pays you for the solar electricity you send back to the grid) now fully in effect and the 30% federal tax credit expired, sizing your system correctly matters more than ever. Oversizing wastes money. Undersizing leaves you still paying a large bill.
If you're asking how much solar you need for a PG&E $400 bill, this guide gives you the math to figure that out — before you sit across from an installer.
If you'd rather start with a calculator first, I Tested 3 Free Solar Calculators in California (2026) — Here's What They Actually Got Right covers what those tools get right and where they fall short.
Quick Answer
A $400/month PG&E bill typically means you're using 900–1,200 kWh/month.
→ To offset that usage, most California homes need an 8–10 kW solar system.
→ With AC and heating loads, budget $21,000–$31,000 installed (before any rebates).
→ Under NEM 3.0, a battery is no longer optional if you want real bill reduction — it changes the math significantly.
→ Payback period in high-rate PG&E territory: 7–9 years without the federal tax credit.
Table of Contents
What a $400 PG&E Bill Actually Means in kWh
Why PG&E's TOU Rates Make Simple Math Unreliable
How AC and Heating Loads Change Your System Size
Why '100% Offset' Is No Longer the Goal Under NEM 3.0
Step-by-Step: How to Calculate Your Solar System Size
Battery or No Battery: How It Changes the $400 Scenario
3 Scenarios for Homes With a $400 PG&E Bill
3 Numbers to Know Before You Talk to an Installer
FAQ
Conclusion
Related Posts
What a $400 PG&E Bill Actually Means in kWh
Before you can size a solar system, you need to know your actual electricity consumption in kilowatt-hours (kWh) — not just your dollar amount. The dollar figure is misleading on its own because PG&E charges different rates depending on when you use power.
PG&E's standard residential tiered rate in 2026 runs roughly $0.30–$0.45/kWh for most of your usage. But if you're on a TOU (Time-of-Use) plan — which PG&E is increasingly defaulting customers to — your peak hours (4–9 PM) cost around $0.54/kWh on the EV2-A plan, while overnight usage drops to $0.23–$0.33/kWh.
To find your kWh usage, log into your PG&E account and look at your 12-month usage history. You'll see a monthly kWh bar chart. Add those 12 numbers and divide by 12 to get your average monthly usage.
Quick estimate:
A $400 bill at an average blended rate of ~$0.38/kWh equals roughly 1,053 kWh/month. At $0.33/kWh average, it's closer to 1,212 kWh/month. Your actual number depends on your rate plan and usage pattern.
Write down your monthly kWh for each of the past 12 months — not just the average. Solar systems are sized to your annual total, and your summer peak month is what determines whether you need a battery.
The rate dynamics behind this are explained in detail in Why Bills Keep Rising and How Solar Can Help (California Electricity Rates 2026).
Why PG&E's TOU Rates Make Simple Math Unreliable
Here's where most online calculators fall short: they take your monthly kWh, divide by 30 days, divide by peak sun hours, and spit out a panel count. That works fine if PG&E paid you the same rate for solar you export as they charge you for power you buy. They don't.
Under NEM 3.0 (CPUC Decision 22-12-056), PG&E pays you roughly $0.02–$0.08/kWh for electricity your solar panels send back to the grid. But they charge you $0.54/kWh during peak hours to buy it back. That's a gap of 7:1 or more. Exporting solar power during the day and buying it back at 6 PM is a losing trade.
What this means for sizing: a system designed to 100% offset your annual kWh on paper will not 100% offset your bill in 2026. You need to think in terms of self-consumption — using your solar power directly, the moment it's produced — or storing it in a battery to use during peak hours.
The practical implication:
if you run your AC from 2–6 PM (which most California households with heavy cooling loads do), a portion of that demand hits during or just before peak pricing. Solar production peaks around noon to 2 PM. Without a battery, there's a mismatch — your panels are producing, but your biggest load comes slightly later when rates spike.
This is why system sizing in 2026 requires looking at your load profile, not just your monthly total.
The full NEM 3.0 policy and its financial impact are covered in NEM 3.0 California Explained (2026): Solar Costs, Battery Savings & Is It Still Worth It?
How AC and Heating Loads Change Your System Size
A $400 PG&E bill caused by AC and heating is fundamentally different from the same bill caused by running a home office with multiple monitors and a chest freezer. The reason is timing.
Central air conditioning — a typical 3-ton unit — draws about 3,500 watts while running. On a 105°F Fresno afternoon, it might run 6–8 hours a day. That's 21–28 kWh from AC alone on a peak summer day. A gas furnace doesn't add to your electric bill the same way, but if you have an electric heat pump (or are planning to add one), winter can spike your usage similarly.
Seasonal Usage Swing for AC-Heavy PG&E Households
Month | Typical kWh (AC-heavy home) | PG&E Rate Pressure |
January–March | 500–700 kWh | Lower — mild temps |
April–May | 700–900 kWh | Moderate — shoulder season |
June–September | 1,100–1,500 kWh | High — AC running daily |
October–December | 600–850 kWh | Moderate — cooling winds down |
For a home averaging $400/month year-round, summer months are often $550–$700 and winter months closer to $200–$280. Your annual total is what determines solar system size — but your summer peak determines whether you need a battery.
If your summer months exceed 1,100 kWh, you'll need a system sized for that peak, or accept a remaining bill during those months. Most installers size for the annual average and let summer carry a small balance — which is often the right financial call under NEM 3.0, since oversizing to cover peak summer produces excess power that exports at 2–8¢/kWh.
If you're also evaluating whether a heat pump makes sense alongside solar, Is It Worth Replacing a 15-Year-Old Gas Heater with a Heat Pump in California (2026)? covers the combined load math.
Why '100% Offset' Is No Longer the Goal Under NEM 3.0
For years, the standard advice was simple: size your solar system to produce 100% of your annual kWh usage. Under NEM 2.0, that math worked because PG&E would credit you near-retail rates (roughly $0.30–$0.40/kWh) for excess solar you exported. You could overproduce in summer, bank credits, and draw them down in winter.
NEM 3.0 changed the economics. Your export credits dropped to roughly $0.02–$0.08/kWh — the 'avoided cost' rate PG&E pays for wholesale power. Meanwhile, what you pay during peak hours stayed at $0.54/kWh on EV2-A. Exporting power is now worth very little. Storing it is worth a lot.
The new math under NEM 3.0 optimizes for self-consumption rate — the percentage of your solar production you use directly in your home, without exporting. A system with 85% self-consumption and a battery will outperform a system with 95% annual offset but 55% self-consumption.
NEM 3.0 Sizing Rule of Thumb (2026):
→ Size your system for 80–90% of your annual kWh need — not 100%.
→ Add a battery to shift afternoon solar into peak evening hours.
→ Target $30–$80/month (minimum connection fee + small remaining usage) rather than zero.
→ Chasing zero under NEM 3.0 requires a much larger system that rarely pencils out financially.
Some installers still pitch 'zero bill' systems sized on paper for 100% offset — but without a battery and proper load analysis, those systems underperform in Year 1.
For a full look at what zero-down financing options exist and how they affect these numbers, see Zero-Down Solar Financing in California (2026): Best Lease, PPA, and Loan Options.
Step-by-Step: How to Calculate Your Solar System Size
The calculation below uses a real example of a PG&E household with a $400/month average bill. Run the same steps with your own numbers.
Step 1: Find Your Annual kWh
The first step in figuring out how much solar you need for a PG&E $400 bill is pulling your actual usage data. Log into PG&E’s MyAccount and pull your 12-month usage. For our example household: 11,400 kWh/year (950 kWh/month average, with summer peaks hitting 1,300 kWh).
Step 2: Apply the NEM 3.0 Sizing Adjustment
Under NEM 3.0, target 80–90% of annual usage. 11,400 kWh × 0.85 = 9,690 kWh/year of solar production needed.
Step 3: Account for System Losses
Real-world solar systems don't produce at 100% of rated capacity. Dust, wiring losses, inverter efficiency, and temperature effects reduce output by about 15–20%. Divide your target by 0.82 (assuming 18% total losses): 9,690 ÷ 0.82 = 11,817 kWh of rated production needed.
Step 4: Calculate Using Peak Sun Hours
PG&E territory spans a wide geography. Peak sun hours (PSH) — the daily equivalent of full-intensity sunlight — vary by location. The Bay Area averages 4.5–5.0 PSH; the Central Valley and Inland areas average 5.5–6.5 PSH. Use 5.0 PSH for a conservative Bay Area estimate.
Annual system output per kW = 5.0 PSH × 365 days × 0.82 (losses) = 1,496 kWh/kW/year
System size needed = 11,817 kWh ÷ 1,496 = 7.9 kW → round up to 8 kW
Step 5: Adjust for AC Load Timing
If your AC runs heavily from 2–8 PM and you're on a TOU rate, add 10–15% to your system size to ensure enough production during the pre-peak afternoon window, or plan for a battery to bridge the gap. Our example: 8 kW + 10% = 8.8 kW → round to 9 kW.
Recommended System Size by PG&E Location
Location (PG&E Territory) | Peak Sun Hours | Recommended System for $400 Bill |
Bay Area (San Jose, Oakland) | 4.5–5.0 PSH | 9–10 kW |
Sacramento Valley | 5.0–5.5 PSH | 8–9 kW |
Central Valley (Fresno, Stockton) | 5.5–6.0 PSH | 7.5–8.5 kW |
North Bay / Coastal (Santa Rosa) | 4.5–5.0 PSH | 9–10 kW |
Foothills / Gold Country | 5.0–5.5 PSH | 8–9 kW |
If you want a second check on these numbers before committing, I Tested 3 Free Solar Calculators in California (2026) — Here's What They Actually Got Right explains which free tools produce reliable estimates and where each one breaks down.
Battery or No Battery: How It Changes the $400 Scenario
Under NEM 2.0, adding a battery was optional for most homeowners. Under NEM 3.0, it's effectively necessary if you want to capture the value of your solar production during the hours that matter most.
Your solar panels produce power from roughly 8 AM to 5 PM. PG&E's peak rate kicks in at 4 PM. Without a battery, the last hour of strong solar production gets exported at $0.02–$0.08/kWh. Then your AC and evening loads kick in and you're buying power at $0.54/kWh. With a battery, you capture that afternoon solar at the point of production and discharge it at 4–9 PM instead.
Scenario | System Size | Battery | Est. Monthly Bill | Installed Cost | Payback (years) |
Solar only, no battery | 9 kW | None | $120–$160/mo | $22,500–$28,000 | 10–12 yrs |
Solar + 10 kWh battery | 9 kW | 10 kWh | $50–$90/mo | $31,500–$44,000 | 8–10 yrs |
Solar + 13.5 kWh battery | 9 kW | 13.5 kWh | $30–$70/mo | $35,500–$49,000 | 8–10 yrs |
The solar-only scenario still cuts your bill significantly — from $400 to roughly $120–$160 — but the remaining bill is driven almost entirely by peak-hour consumption that solar can't address without storage. If your target is under $100/month, a battery is the path that pencils out.
The SGIP (Self-Generation Incentive Program) battery rebate may apply to your installation if you're in a high fire-risk zone or meet income qualifications. Current SGIP availability varies by funding wave — check cpuc.ca.gov before assuming it's active.
For a full breakdown of what batteries cost and what rebates currently exist, Solar Battery Costs in California 2026: Price Breakdown covers the numbers by system size and scenario.
Three Scenarios for Homes With a $400 PG&E Bill
The right system size varies by location, home size, and how heavily AC-weighted your usage is. The three profiles below cover the most common situations in PG&E territory.
Scenario A: Bay Area Home, 1,800 sq ft, AC + Gas Heat, $380–$420 Average
Annual usage: 10,800 kWh. Location: San Jose (5.0 PSH). Recommended system: 9 kW solar + 10 kWh battery. Estimated installed cost: $31,000–$38,000. Expected monthly bill after solar: $55–$80. Payback period: 8–9 years.
Scenario B: Central Valley Home, 2,200 sq ft, Heavy AC (3.5-ton unit), $420–$480 Summer Peak
Annual usage: 13,200 kWh (heavily summer-weighted). Location: Fresno (5.8 PSH). Recommended system: 10 kW solar + 13.5 kWh battery. Estimated installed cost: $37,000–$46,000. Expected monthly bill after solar: $40–$80 (higher in peak summer). Payback period: 8–10 years.
Scenario C: Sacramento Suburbs, 1,500 sq ft, Heat Pump (Electric Heat + AC), $360–$440 Year-Round
Annual usage: 11,400 kWh (more evenly distributed with electric heating). Location: Sacramento (5.3 PSH). Recommended system: 8.5 kW solar + 10 kWh battery. Estimated installed cost: $32,000–$40,000. Expected monthly bill after solar: $45–$75. Payback period: 7–9 years.
All three scenarios assume cash or loan financing in 2026 without the federal ITC.
If you're evaluating lease or PPA structures instead, the monthly cost comparison looks different — Zero-Down Solar Financing in California (2026): Best Lease, PPA, and Loan Options walks through how each structure affects long-term savings.
Three Numbers to Know Before You Talk to an Installer
When you sit down for a solar estimate, most salespeople will ask for your average monthly bill and use that to generate a system proposal. That single number isn't enough for an accurate quote — and proposals built on it are designed to look good on paper, not to reflect your actual load.
Before any conversation with an installer, have these three numbers ready:
1. Your 12-month total kWh — not just your dollar amount. Pull this from PG&E MyAccount. This is your actual energy demand, before rate distortion.
2. Your summer peak month kWh — the highest single month in the last year. This tells you whether your system needs to be sized for average or peak load. The difference can be 1.5–2 kW of additional capacity.
3. Your current rate plan — specifically whether you're on E-1 (tiered), EV2-A (TOU with EV incentive), or another plan. Your installer should be modeling savings against your actual rate structure, not a generic average.
With these three numbers, you can cross-check any proposal against the calculation in Section 5 yourself. A reputable installer will show you their production estimate in kWh per year — not just 'your bill goes to zero.' If a quote doesn't include projected annual kWh production in writing, ask for it before signing.
If you'd rather get estimates without sharing your personal contact information first, How to Get a Solar Estimate Without Sharing Your Contact Info covers tools and approaches that let you compare options before committing to any sales process.
For a full list of what installer quotes typically leave out, 7 Hidden Solar Installation Costs in California (2026): What Your Quote Isn't Telling You covers the line items that most often show up later.
FAQ: How much solar do I need PG&E $400 bill
Q: Is a $400 PG&E bill high enough to justify solar in 2026?
A: Yes — $400/month puts you well into the range where solar delivers a positive return. In PG&E territory, the payback threshold is generally around $150–$200/month. At $400, you're spending $4,800/year that solar can largely replace. Even without the federal 30% tax credit, which expired December 31, 2025, the payback math works — though timelines extend by 2–3 years compared to 2024 installations.
Q: Can I get my PG&E bill to zero with solar?
A: Technically possible, but not financially optimal under NEM 3.0. You'd need to oversize your system significantly and pair it with a large battery to cover peak-hour demand. In practice, most well-designed 2026 solar-plus-storage systems bring a $400 bill down to $30–$80 — which is mostly PG&E's mandatory minimum connection fee ($10–$15/month) plus any remaining peak usage. Chasing true zero typically adds $15,000–$25,000 to your system cost for marginal additional savings.
Q: My bill is highest in summer. Should I size for the summer peak?
A: Size for your annual average, not your summer peak. Solar installers calculate system size based on annual kWh production versus annual kWh demand. Sizing for your peak summer month results in significant overproduction the rest of the year — and under NEM 3.0, that excess exports at $0.02–$0.08/kWh. A battery is a better solution for peak summer load than oversizing the panel array.
Q: Does the 30% federal solar tax credit still apply in 2026?
A: No. The 30% residential clean energy tax credit (ITC) under IRC Section 25D expired December 31, 2025, and does not apply to systems installed in 2026. This increases the effective cost of going solar by roughly $6,300–$8,400 for an 8–9 kW system compared to 2024–2025 installations. California's own incentives (SGIP for batteries, IID or LADWP rebates for applicable customers) remain available but vary by utility territory and current program funding.
Q: How long does solar installation take from quote to permission to operate?
A: In most PG&E territory, the timeline from signed contract to system activation runs 2–4 months. The quote and design phase takes 1–2 weeks. Permitting with your local jurisdiction typically takes 3–6 weeks. Physical installation is 1–2 days. Then PG&E's interconnection and Permission to Operate (PTO) process adds another 2–6 weeks. Delays usually come from permit backlogs or PG&E's queue, not the installation itself.
Q: Is my roof a good fit for solar?
A: South-facing roofs at a 15–35 degree pitch are ideal. West-facing roofs are actually valuable under NEM 3.0 because they produce power in the late afternoon — closer to peak pricing hours — even though total annual output is lower than south-facing. East-facing roofs produce morning power when rates are low. North-facing roofs in California can work if you have enough roof space to compensate for lower production angles. Your installer should provide a shading analysis using tools like Aurora or Solargraf before finalizing the design.
Q: Should I upgrade my electrical panel before going solar?
A: If your home has a 100-amp panel, a solar system over 7–8 kW will likely require an upgrade to 200 amps. This costs $2,000–$4,500 in California and is sometimes bundled into the solar quote or listed as a separate line item. Always ask your installer whether a panel upgrade is included or separate — it's one of the most common hidden costs in proposals.
The full decision framework is in Electrical Panel Upgrade for Solar & EV in California (2026).
Q: What happens to my solar system if I sell my house?
A: If you own your system outright (cash purchase or solar loan), it transfers with the home and typically increases resale value — California studies have shown solar adding $10,000–$15,000 in home value for a typical 6–8 kW system. If you have a solar lease or PPA (Power Purchase Agreement — a contract where you buy power from a third-party-owned system on your roof), the new buyer must either assume the contract or you'll need to buy out the system before closing. Lease transfers can complicate home sales, which is one reason loans are often preferable to leases for long-term homeowners.
Start With the Math, Not the Sales Pitch
That retired teacher in Fresno eventually went solar — a 9.2 kW system with a 10 kWh battery. Her last PG&E bill was $54. Not zero, but she stopped dreading the mail in August.
Her system worked because we sized it from actual usage data, accounted for AC load timing, and set realistic expectations under NEM 3.0. She didn't go in blind, and she didn't let a salesperson pick her system size from a single dollar figure on a bill.
Three steps to get there before your first installer conversation:
4. Pull your 12-month kWh history from PG&E MyAccount and find your annual total and your summer peak month.
5. Use the calculation in Section 5 to estimate your system size based on your location and usage.
6. Get at least two quotes from CSLB-licensed installers (verify at cslb.ca.gov) and ask each one to show you projected annual kWh production in writing.
If you're still early in the research phase, I Tested 3 Free Solar Calculators in California (2026) — Here's What They Actually Got Right covers the free tools worth using before your first installer conversation.
Related Posts
If this guide raised questions about adjacent topics, these posts cover them with the same level of detail:
About the Author
James Ree has eight years of experience in electrical, HVAC, and solar wholesale in Los Angeles, supplying equipment to residential and commercial installers. He writes practical guides on solar, EV charging, battery storage, and home electrical systems for U.S. homeowners.
Disclaimer
Rate figures cited are based on 2025–2026 published tariff schedules and CPUC filings. System cost ranges reflect California installer pricing as of early 2026. Verify current utility rates and program availability directly with PG&E and cpuc.ca.gov before making financial decisions.
