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Is Solar Worth It? Calculate Your Savings
Find out your solar panel ROI, payback period and 20-year savings in seconds. Built on real state-by-state sunshine, electricity rate and feed-in tariff data.
Calculate My SavingsYour situation
Polycrystalline / entry monocrystalline. Lower cost, needs more roof area.
Standard panels need about 7 m² per kW. Max that fits: 5.7 kW. We recommend 5 kW.
Rates used for California
Electricity: $0.30/kWh · Feed-in: $0.08/kWh
Sunshine: 5.5 kWh/m²/day · Install: $2.75/W
Recommended system
5 kW
Payback period
6.8 yrs
Net install cost
$9,625
after $4,125 incentive
Annual production
7,829 kWh
Year-1 savings
$1,315
10-year net savings
+$5,101
20-year net savings
+$23,924
CO₂ offset (20 yrs)
56.8 t
Cumulative savings over 20 years
Includes the federal tax credit, panel degradation and rising electricity prices.
Stay on the grid
$48,367
spent on electricity over 20 years
Go solar
+$23,924
net position over 20 years (savings minus install cost)
Estimates only. Assumes ~40% of solar is used on-site (rest exported at the feed-in tariff), a 78% performance ratio and 3%/year electricity price rises. Get at least three certified installer quotes before committing.
How the calculator works
Tell us where you live
Solar irradiance, electricity prices and feed-in tariffs vary hugely by state — we use local data for every US and Australian state.
Add your bill and roof
Your monthly power bill sets how much you can save; your roof size sets how big a system you can fit. Pick standard or premium panels.
See your real ROI
We project generation, savings, payback period and 20-year net savings — factoring in panel degradation and rising electricity prices.
Solar savings FAQ
How is the solar payback period calculated?
Payback period is the time it takes for your cumulative electricity savings to equal your net installation cost. We project year by year, applying panel degradation (around 0.5% per year) and electricity price escalation, then find the point where your running savings cross the upfront cost. For most homes the payback lands between 4 and 10 years.
How much can I save with solar panels over 20 years?
It depends on your electricity rate, local sunshine, and system size. The calculator multiplies your system output by your retail electricity rate (plus feed-in tariff credits for exported power) and compounds rising power prices over 20 years, minus your upfront cost. Many households see five-figure net savings over two decades.
What affects my solar savings the most?
The three biggest drivers are your local electricity price (higher rates mean faster payback), solar irradiance where you live (more sun means more generation), and how much of the solar power you use on-site versus export. Available incentives such as the US federal tax credit also cut your net cost significantly.
How big a solar system do I need for my roof?
Standard panels need roughly 7 m² of roof per kW installed, while high-efficiency premium panels need about 5.5 m² per kW. Enter your roof size and the calculator recommends the largest standard system size (3, 5, 6.6 or 10 kW) that physically fits, or you can pick a size directly.
Are these figures guaranteed?
No. Every result on this site is an estimate built from representative 2026 data for solar irradiance, electricity rates, feed-in tariffs and installation costs by state. Real quotes vary with your roof orientation, shading, installer and retailer plan. Always get at least three certified installer quotes before committing.