Home · solar savings
Estimate what rooftop solar could save you. Enter your electric bill and system cost to see the payback period and 25-year savings — after the federal tax credit.
Cumulative savings vs. system cost — the cross is your payback
Solar panels save money in a simple way: they generate electricity your home would otherwise buy from the utility. Every kilowatt-hour your roof produces is one you don’t pay the grid for, so the value of solar is really the value of the electric bill it offsets. That’s why a higher bill makes solar more attractive — there’s simply more to replace.
The catch, and the reason payback is worth modeling, is that an electric bill isn’t static. Utility rates tend to climb year after year, which means the bill you’re offsetting gets bigger over time. A system that looks like a slow payback against today’s rate looks better once you account for a decade or two of rising prices. Solar essentially locks in much of your cost up front and lets you ride out rate increases that would otherwise keep pushing your bill higher.
The tool takes a handful of real inputs and projects them across the typical 25-year life of a system:
From those, it calculates your net cost after the credit, the payback period in years, and your 25-year net savings. It also assumes panels lose roughly 0.5% of their output per year — real-world degradation — so the later years are modeled a little more conservatively than the early ones. The chart plots cumulative savings against your net cost; where the two lines cross is your payback point.
Start with your actual numbers. Pull your average monthly bill from a recent statement, and use the total price from a real quote rather than a rule of thumb — install costs vary a lot by region and roof. Leave the credit at 30% unless you have a reason to think you won’t qualify. Set the offset to match what an installer projects your system will cover, and pick a utility rate increase you’d actually believe; a modest figure gives a more honest estimate than an optimistic one. Then adjust one input at a time to see how sensitive the payback is — you’ll quickly learn whether a cheaper install or a higher offset moves the needle most.
The single biggest incentive for most buyers is the federal Residential Clean Energy Credit, worth 30% of a qualifying system’s cost. It’s a tax credit, so it reduces what you owe the IRS dollar-for-dollar rather than just lowering your taxable income, and unused credit can generally be carried forward to a later year. To claim it yourself you need to own the system — a lease or PPA doesn’t let you take it.
On top of the federal credit, state and local incentives, utility rebates and net metering rules vary enormously from one place to the next. Net metering — how much your utility pays for the excess power you send back to the grid — can make a real difference to your effective savings, and some states are far more generous than others. This calculator models the federal credit and your bill offset; treat any state-specific perks as upside on top of what you see here, and check your own utility’s current rules.
Say your average bill is $180 a month on a $22,000 system, and the panels offset 90% of your usage. The 30% federal credit knocks $6,600 off the price, bringing your net cost to about $15,400. The panels offset roughly $1,944 of electricity in the first year ($180 × 12 × 90%), and that figure grows as utility rates rise. At a 3% annual rate increase, cumulative savings cross your net cost somewhere around year eight or nine — your payback point — after which the system keeps saving for the remainder of its 25-year life, adding up to tens of thousands in net savings.
How you pay for solar matters as much as whether you go solar at all. When you own the system — cash or a loan — you claim the 30% federal credit yourself and keep every dollar the panels save, which is what produces the long-run numbers this calculator shows. With a lease or power purchase agreement, the provider owns the panels, claims the credit, and sells you the power; your monthly cost may dip, but you forgo the credit and most of the savings, and the contract can complicate a future home sale. For buyers who can use the tax credit and finance the rest sensibly, owning almost always wins. This tool assumes an owned system, so if you’re weighing a lease, treat its output as the best case you’d be giving up.
If solar isn’t the right move yet, the fastest wins are usually on the bill itself — start with how to lower your electric bill and, seasonally, lowering your electric bill in winter. To weigh a big purchase like this against a home loan, try the mortgage calculator; to decide where to keep the cash you’d put toward a system, see where to park cash; and to understand how rising prices erode money you’re not putting to work, run the inflation calculator. You can browse the full set at money calculators. This tool is an estimate for education, not financial advice.
For most US homes the payback period lands somewhere between 7 and 12 years, though it depends heavily on your electric bill, install cost and local incentives. A high bill paired with a reasonably priced system pays back fastest, because the panels are offsetting more dollars each month. This calculator shows your specific payback in years based on the numbers you enter, including the 30% federal credit and the rate at which your utility’s prices rise.
The Residential Clean Energy Credit lets you claim 30% of the cost of a qualifying solar install as a credit against your federal income taxes for the year the system is placed in service. It’s a credit, not a deduction, so it reduces your tax bill dollar-for-dollar, and if it’s larger than what you owe in one year you can carry the unused part forward. You generally need to own the system — buy it with cash or a loan — to claim it yourself. This is general information, not tax advice; confirm your eligibility with a tax professional.
It depends on your electric bill, how much sun your roof gets, what you pay per kilowatt-hour and the incentives in your state. Solar tends to make the most sense when you have a high bill, a south-facing roof with little shade, and rising utility rates — the more you’re paying the grid, the more there is to offset. Use the calculator as a first-pass estimate, then get a couple of itemized quotes before deciding. It’s an estimate, not a guarantee.
Because panels are typically warrantied for around 25 years and utility rates tend to rise over time, lifetime savings can run well into the tens of thousands of dollars for a home with a healthy bill — but the figure swings widely with your inputs. The calculator projects 25 years of savings, assumes your utility’s rates keep climbing, and accounts for panels losing roughly 0.5% of their output each year, then subtracts your net system cost to show the net savings.
Owning your system — paying cash or financing it with a loan — lets you claim the 30% federal credit and keep all of the bill savings, which is why buying usually produces the better long-run outcome. With a lease or a power purchase agreement (PPA) the company owns the panels and claims the credit, while you pay them for the power; your monthly cost may drop a little, but you give up the credit and most of the upside. This calculator models an owned system.
Yes, and rising rates actually work in your favor: every time your utility raises prices, the electricity your panels produce is worth more, so your savings grow over time. The calculator lets you set an annual utility rate increase to model this. If rates were ever to fall, your savings would grow more slowly, which is why a realistic rate assumption matters — the tool defaults to a modest increase rather than an optimistic one.
Free · every Sunday
What moved in the markets, the guides worth reading, and what it all means — in one short email. No noise, no bank linking, leave anytime.
Tell me if you know how this feels. You go to your mailbox and see a letter from your electric service provider. You open it, and your jaw drops to the floor looking at the bill.
As winter approaches, you already know that your electric and gas bill is going to get quite a bit higher All hope is not lost though.
The general consensus agrees that the age range of Millennials are individuals that were born between the early 1980s and early 2000s.
The Sunday Digest
Metals, rates and inflation, digested into one short email every Sunday. Free, no bank linking, leave anytime.
