Solar Bill Higher Than Promised? How to Find Out Why

"My bill is higher than they said it would be" is one of the most common posts in homeowner solar groups, and it rarely has a single cause. A bill after solar has more moving parts than the one before it: what the panels make, what the house uses, what the utility pays for power you send back, when the utility settles the account, and what you pay the company that financed the system. Each can be checked with numbers you already have. This guide walks through them in the order worth checking.

Start with kWh, not dollars

Dollars move with rates and fixed charges. Kilowatt-hours tell you what actually happened. Pull three sets of numbers for the last 12 months: the kWh you bought from the grid and the kWh you sent back, both on your utility bills, and the kWh your system produced, in your monitoring app. Your total household use is what you bought, plus what the panels made, minus what you sent back. Compare that total with the year before solar, and compare the panels' output with the first-year production estimate in your proposal. Most bill problems fall out of those two comparisons.

You may be using more electricity

A system sized to last year's usage cannot cover a house that now uses more. An electric vehicle, a pool pump, a new air conditioner, a home office or another person in the house can each add a large number of kWh a year. If your total use went up and the panels' output did not go down, the bill is doing what the math says it should. The fix is a conversation about adding panels or storage, not a dispute.

The system may be making less than it should

Check your monitoring against your own history. A healthy system traces a smooth curve on clear days, and its daily totals usually land close to the same season last year, allowing for weather. A south-facing system typically makes 40 to 50 percent fewer daily kWh in December than in June, so compare October with last October, not with July. Our guide to reading your monitoring covers the warning signs, and if the app went dark when your installer closed, our guide to claiming monitoring in your own name walks through it.

Common causes of a real drop are a failed microinverter or string, new shade from a growing tree, heavy soiling and a tripped breaker. If the system was never given permission to operate by the utility, it may not have been allowed to run at all. If something looks wrong, our guide to a solar system that is not working walks through the checks, starting with the safe ones.

Your exported kWh may be worth less than the proposal assumed

Most solar proposals assume a value for the power your panels send to the grid at midday. If that assumption was generous, every exported kWh falls short of it.

In California, new solar customers are on the Net Billing Tariff, often called NEM 3.0, which the California Public Utilities Commission adopted in Decision D.22-12-056 for applications from April 15, 2023. The CPUC says the credit for exported power "is usually lower than the retail rate," though it can rise above it on late summer evenings. A proposal that valued your exports at the retail rate overstated them.

In Nevada, NV Energy credits exports from newer solar customers at 75 percent of the retail rate. Our net metering guide explains both states' rules and what to ask for in a quote.

In California, a large bill can arrive once a year

PG&E's Solar Billing Plan sends monthly billing statements and then, at the end of your 12-month billing cycle, a True-Up statement that settles the year's charges against your accumulated credits. A household that ran a balance through the winter can see a large amount come due at once. If your monthly statements show a growing balance, that is the number to watch, and setting money aside for it each month avoids the shock. Other California utilities publish their own solar billing plan pages that explain their settlement dates.

Rates and fixed charges may have changed

Your utility's prices do not stay where they were when you signed. California's average residential rate was about 32.5 cents per kWh in 2025, according to the U.S. Energy Information Administration (preliminary figures). Our Rate Hike Tracker shows your state's trend.

California's largest utilities also now add a fixed monthly Base Services Charge for most residential customers, which comes with a lower price per kWh, PG&E says. A fixed charge you pay whatever your panels make, paired with lower per-kWh prices, makes each kWh your system saves worth a little less. The net metering guide has the amount and start dates by utility.

A lease or PPA payment may have gone up

If you lease the system or buy its power under a power purchase agreement, your solar payment is part of what you pay for electricity. Many of these contracts raise the payment every year by a set percentage, called an escalator. At 2.5 percent a year, a $200 first-year payment reaches about $320 in year 20. A rep's comparison that shows only the first year leaves that growth out. Our guide to red flags in a solar contract shows what to look for in the escalator clause.

The proposal may have been optimistic from the start

Compare the first-year production in your proposal with what the system actually made in its first full year. A large gap with no equipment fault usually means the design overestimated your roof: shading, orientation or tilt that the estimate did not account for. Some proposals also show savings as an offset percentage, which says nothing about when you use power or what an exported kWh is worth.

If you lease the system or have a power purchase agreement, read your contract for a production guarantee. Many promise a minimum number of kWh over a set period, with a credit or refund if the system falls short. Compare the guaranteed kWh with your monitoring history and file the claim with the company that owns the system, in writing. Our guide to whether you still have to pay if your installer is gone covers that claim and the others that hold up.

What to do next

Write down the numbers from the kWh check above, and keep your proposal next to them. If the system is producing less than it should, get it looked at before you argue about the bill. If your exports or your rates explain the gap, ask your utility whether a different rate plan fits the way your house uses power. If you believe the sale was misrepresented, our guide to getting out of a solar contract covers the cancellation windows, the paths that hold up later and the public agencies that take complaints.