Solar Panel Costs & Savings
A useful solar estimate connects five separate numbers: the home's electricity use, likely solar production, net installed cost, the value of solar used at home, and the value of solar exported to the grid. Work through those inputs in order instead of starting with a sales quote or a universal payback claim.
Work through the numbers in this order
A calculator is useful only when its inputs describe the same real-world scenario.
- 01
Start with one year of electricity use
Use 12 months of bills if possible. Annual kWh is a better starting point than one unusually hot or cold month. Note whether future EV charging, electric heating, or efficiency upgrades could materially change that demand.
- 02
Estimate production before savings
System size in kW is not the same as annual production in kWh. Location, roof direction, tilt, shading, equipment, and losses affect output. Use a site-specific production estimate, then test a conservative range rather than one sales forecast.
- 03
Separate self-use from export
Solar used in the home can avoid the retail import rate; exported solar may receive a different credit or tariff. Model those streams separately. A battery can shift timing, but it also adds cost, capacity limits, losses, and warranty constraints.
- 04
Calculate payback from net cost
Use the installed price after only the incentives you are actually eligible to receive. Include financing cost when comparing a loan, lease, power-purchase agreement, or cash purchase. Divide net cost by realistic annual benefit for a simple payback estimate.
Calculators
Solar System Size Calculator
Before pricing solar, you need to know what size system covers your usage. This calculator estimates…
SolarSolar Panel Cost Calculator
Solar is usually priced per watt of capacity. Enter your system size and price per watt to estimate …
SolarSolar Panel Payback Calculator
Solar pays off only after it has saved you more than it cost to install. This calculator estimates y…
SolarSolar Savings Calculator
Estimate the value of solar electricity you use at home plus the credit or payment for surplus sent …
SolarSolar Export Earnings Calculator
When your panels make more than you use, the surplus is exported to the grid for a payment. This cal…
SolarHome Battery Payback Calculator
A home battery saves money by storing cheap (or solar) electricity and using it when power is expens…
Inputs that can change the answer
Test a realistic range for these variables instead of relying on one best-case result.
- Annual production
- Use a location- and roof-specific estimate in kWh, not only the panel nameplate total.
- Net installed cost
- Include equipment, labor, permits, interconnection, financing, and only confirmed incentives.
- Import and export value
- Use the rates and credit rules in your utility or supplier agreement; they can differ substantially.
- Timing and storage
- Self-consumption depends on when the home uses electricity. Storage changes timing but not for free.
- Scenario range
- Test lower production, lower export value, and changing electricity prices before treating payback as a decision.
Guides
Is Solar Worth It? How to Actually Tell
Solar is a great investment for some homes and a poor one for others. Here is how to tell which you are, without the sales pressure.
6 min readHow Many Solar Panels Do I Need for My House?
Sizing solar wrong is the most expensive mistake homeowners make. Here is the actual maths, in plain English.
6 min readSolar Panels vs. Battery Storage: Which Should You Buy First?
They solve different problems. Here is how to know which one your home actually needs first.
Primary guidance used for this topic
- U.S. Department of Energy - Homeowner's Guide to Solar Site suitability, production estimates, financing, storage, net metering, and consumer safeguards.
- U.S. Department of Energy - Will I Save Money with Solar Energy? Payback framing and the household-specific nature of savings.
Sources checked August 12, 2026. Rates, incentives, equipment, and local requirements can change.