Solar True-Up Bill: What It Is, Why It’s High, and How to Fix It
A plain-English guide to understanding — and reducing — your annual solar settlement
What You Need to Know
A true-up bill is your utility’s annual settlement — the final tally of what you owe after 12 months of solar credits and grid charges are netted out. If you owe more than you earned in credits, that balance arrives as a lump-sum bill.
A high true-up doesn’t necessarily mean your solar isn’t working. It usually means there’s a gap between when your panels produce power and when you actually use it — and that gap costs money under time-of-use rates.
This guide explains how true-up bills work, why they’re often higher than expected, and what you can do about it.
How Your True-Up Bill Is Calculated
Each month, your utility tracks two things: the energy your solar system sends to the grid (exports) and the energy you pull from the grid (imports). Under net metering, your exports earn credits and your imports generate charges.
Here’s the catch: those credits and charges aren’t equal. Under time-of-use rates, electricity costs more during peak hours (typically 4-9 PM) and less during off-peak hours (when your solar is producing). So even if your panels produce the same number of kilowatt-hours you consume, the dollar values don’t match up.
Simple Example: How Timing Creates a Bill
Your solar produces 30 kWh during the day — exported to the grid at off-peak rates (~8¢/kWh) = $2.40 in credits
You use 25 kWh in the evening — imported from the grid at on-peak rates (~48¢/kWh) = $12.00 in charges
Over 12 months, that adds up to a true-up bill of $3,500+
This is why production alone doesn’t tell the whole story. The timing of production vs. consumption is what drives your true-up.
NEM 1.0 vs. NEM 2.0 vs. NEM 3.0
The timing mismatch problem is worst under NEM 3.0 (California systems installed after April 2023), where export credits are drastically reduced. NEM 1.0 and 2.0 customers get better export rates, but can still face high true-ups if they’re on the wrong rate plan or their usage has grown since installation.
5 Reasons Your True-Up Bill Is Higher Than Expected
1. Timing Mismatch
Your panels produce power midday when rates are low. You use most power in the evening when rates are high. Even with 100% annual kWh offset, you can owe hundreds or thousands because of the price difference between export credits and import charges.
What to do: Shift heavy loads (EV charging, pool pump, laundry) to midday solar hours. This uses your solar directly instead of exporting it at low rates and importing at high rates. See our full guide on load shifting.
2. Wrong Rate Plan
Different TOU plans define peak hours differently and have different price spreads. The wrong plan can cost you hundreds per year — even when your solar production looks fine on paper. Many homeowners are still on the default rate their utility assigned, which is rarely the best option for solar.
What to do: Log into your utility account and check which rate plan you’re on. Compare it to solar-optimized TOU plans (like SCE’s TOU-D-PRIME or PG&E’s E-TOU-D). Switching is free and takes about 10 minutes online. More details in our rate plan optimization guide.
3. System Underperformance
Dirty panels, new tree shading, inverter problems, or wiring issues can reduce your production by 10-25% without obvious symptoms. If your system isn’t producing what it should, every other optimization is working with a handicap.
What to do: Open your monitoring app and compare recent production to the same month last year. A drop of 15%+ (beyond normal degradation) suggests a problem. Check for visibly dirty panels, new shading, or any panels/strings showing zero output. Our cleaning and maintenance guide covers what to look for.
4. Usage Has Increased
Added an EV, pool, home office, or upgraded to a heat pump since your system was installed? Your energy consumption may have grown beyond what your original system was designed to offset. The system you bought three years ago was sized for the home you had then — not the home you have now.
What to do: Compare your annual consumption now vs. when your system was installed (your utility account shows historical usage). If consumption has grown significantly, you may need to optimize usage timing before considering adding panels. Our free calculator can show how many panels your home needs today for full offset.
5. Battery Issues (or No Battery)
If you don’t have a battery, you’re exporting cheap solar and buying back expensive peak power — the core timing mismatch problem. If you do have a battery, poor programming can actually make things worse. We see batteries charging from the grid at peak rates instead of from solar, or discharging during off-peak hours when it doesn’t help.
What to do: If you have a battery, check that it’s set to charge from solar (not the grid) and discharge during your rate plan’s on-peak window (usually 4-9 PM). If you’re considering adding a battery, read our honest battery guide first — it’s not the right move for everyone.
Can You Reduce Your True-Up Without Buying Equipment?
Often, yes. The first three fixes — load shifting, rate plan switching, and fixing battery settings — are all free and can reduce true-up bills by 30-60% depending on your situation.
The key insight is that most high true-up bills are a timing and pricing problem, not a production problem. Your panels may be working perfectly — you’re just using power at the wrong time or on the wrong rate plan.
Here’s a practical order of operations:
- Switch to the best rate plan — free, takes 10 minutes, often the biggest single improvement
- Shift heavy loads to solar hours — free, requires some schedule changes
- Fix battery settings — free if you already have a battery
- Clean panels / address shading — $100-$300, do this if production has dropped
- Add battery storage — $10,000+, only after exhausting free options
- Add more panels — $5,000+, only if system is genuinely undersized
💡 Most People Skip Steps 1-3
The majority of solar homeowners with high true-up bills haven’t optimized their rate plan or usage timing. These free changes can save $500-$2,000+ per year. Always exhaust the $0 fixes before spending money on equipment.
Will a Battery Lower My True-Up Bill?
This is the most common question we hear. The honest answer: it depends.
A battery helps when your main issue is timing mismatch — you’re producing solar midday but consuming heavily in the evening. A properly sized battery captures daytime solar and releases it during expensive peak hours, which directly reduces the charges that drive your true-up.
A battery doesn’t help when your system is undersized (not enough total kWh), your panels are underperforming, or you’re on a rate plan with a small peak/off-peak spread. In those cases, a $10,000+ battery won’t solve the underlying problem.
And importantly: a poorly programmed battery can make things worse. If it charges from the grid during peak hours instead of from solar, or discharges during off-peak hours when rates are already low, it’s costing you money instead of saving it.
⚠️ Federal Tax Credit Expired
The 30% federal residential clean energy tax credit (Section 25D) expired December 31, 2025. This changes the battery payback math significantly. State programs like California’s SGIP may still offer rebates — check current availability before making a decision. Read our full battery storage analysis for updated numbers.
“The report is great. Having this objective report gives me a great tool as I’m getting ready to meet with solar salespeople to upgrade my system. After getting a big True-up bill from Edison, I knew my system was undersized and I needed to do something, but I wasn’t sure what.
PowerMy gave me the clarity I needed. I’d rate it a 10 out of 10 and would absolutely recommend it to other solar owners.”
— August I., Palm Desert
Frequently Asked Questions
Q: When does the true-up bill arrive?
Your true-up arrives on your solar anniversary — 12 months after your system was interconnected with the utility. It’s the final settlement for that billing year. Check your utility account to find your anniversary date so you’re not caught off guard.
Q: Can I get a refund if my solar produces more than I use?
Most utilities pay a small per-kWh credit for excess annual production — typically 2-4 cents per kWh, not the retail rate. This is called Net Surplus Compensation (NSC). It’s not a meaningful refund, which is why oversizing your system rarely makes financial sense.
Q: Can I pay my true-up bill in installments?
Many utilities offer payment plans for large true-up bills. Contact your utility to ask about installment options. Some also offer “level pay” programs that spread your estimated annual cost into equal monthly payments — which doesn’t reduce the total, but avoids the lump-sum surprise.
Q: My true-up was $0 last year but high this year. What changed?
Several things could have shifted: rate plan changes by your utility, increased household consumption (new EV, pool, appliances), panel degradation or new shading, changes to net metering rules, or a combination. Compare your utility’s rate schedule and your consumption data year-over-year to pinpoint what changed.
Q: How do I tell if my solar system is underperforming?
Compare recent monthly production to the same months last year and to your original system design estimate. A drop of 15%+ beyond normal seasonal variation suggests an issue — dirty panels, equipment problems, or new shading. Your monitoring app (Tesla, Enphase, SolarEdge) should show production trends over time.
Q: Does NEM 3.0 make true-up bills worse?
Yes, significantly. Under NEM 3.0 (California systems installed after April 2023), export credits are much lower than under NEM 1.0 or 2.0. This makes the timing mismatch problem more expensive — you’re selling midday solar for pennies and buying evening power at full retail rates. Batteries become more important under NEM 3.0, but the economics still depend on your specific usage and rate plan.
Q: My installer says everything is fine but my bills are still high. What’s going on?
Your installer is looking at production data — and they may be right that your panels are working. But production is only half the equation. The other half is when and how you use power, which rate plan you’re on, and how export credits compare to import charges. These are billing and consumption issues that installers typically don’t analyze.
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