Solar Panel Savings Calculator
Find out exactly how much you can save with solar. Enter your electricity bill, system details, and location to get your payback period, annual savings, and 25-year ROI.
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How the Solar Savings Calculator Works
This calculator uses industry-standard formulas to estimate your solar savings. Here is a breakdown of each step in the calculation:
A 7 kW system in a 5.5-sun-hour zone at 80% efficiency produces roughly 11,193 kWh per year — enough for most average US homes.
If you produce 11,193 kWh at $0.16/kWh with full net metering, you save about $1,791 per year in the first year. This grows as electricity rates rise.
Net cost is your total system price minus tax credits and rebates. Divided by your average yearly savings, this gives the number of years to break even on your investment.
ROI measures what you get back relative to what you spent. A $15,000 net investment returning $45,000 in savings = 200% ROI over 25 years. Panel degradation of 0.5%/year is factored in.
What Affects Your Solar Savings
Multiple variables determine how much you will actually save with solar. Understanding each helps you interpret your estimate more accurately.
Peak sun hours range from 3.5 in the Northeast to 6.5+ in the Southwest. More sun hours means more electricity generated per kW of installed capacity.
The higher your rate per kWh, the more valuable each unit of solar power. Hawaii ($0.40/kWh) and California ($0.30+/kWh) see much faster paybacks than Louisiana ($0.12/kWh).
South-facing roofs at a 30° tilt produce the most power in the Northern Hemisphere. East or west-facing roofs produce 15–20% less. Shading from trees or chimneys can reduce output significantly.
Full 1:1 net metering means every excess kWh you send to the grid earns a full retail credit. Some utilities pay only wholesale rates, which cuts the value of excess production.
Solar panels lose about 0.5% of their output each year. After 25 years, a panel is still producing around 87.5% of its original capacity. Most quality panels carry 25-year performance warranties.
Federal tax credits, state rebates, and local utility incentives can cut your net system cost by 20–40%. Check DSIRE.org for every incentive available in your state and zip code.
How to Size Your Solar System
Choosing the right system size avoids both overspending and under-producing. Use this quick sizing method:
- Find your annual kWh usage on your electricity bills. The US average is about 10,500 kWh per year, or 875 kWh per month.
- Divide by your peak sun hours × 365. At 5 sun hours: 10,500 ÷ (5 × 365) = 5.75 kW system needed to cover 100% of usage.
- Add 10–20% buffer for inverter and wiring losses, shading, and future load growth (EVs, heat pumps).
- Count your panels. At 400W per panel, a 7 kW system needs about 18 panels, covering roughly 360 sq ft of roof space.
- Get 3–5 installer quotes and compare cost per watt (reasonable range: $2.50–$3.50/W all-in including labor, permits, and equipment).
| Monthly Bill | Est. System Size | Approx. Cost | Panels (400W) |
|---|---|---|---|
| $75–$100 | 3–4 kW | $8,400–$13,000 | 8–10 panels |
| $100–$150 | 4–6 kW | $11,200–$19,500 | 10–15 panels |
| $150–$200 | 6–8 kW | $16,800–$26,000 | 15–20 panels |
| $200–$300 | 8–12 kW | $22,400–$39,000 | 20–30 panels |
| $300+ | 12–20 kW | $33,600–$65,000 | 30–50 panels |
Costs are estimates based on $2.80–$3.25/W average US installation cost in 2026. Actual quotes vary by region, roof complexity, and equipment brand.
Frequently Asked Questions
How much money can solar panels save per year?
The average US homeowner saves $1,400 to $1,800 per year with solar panels. Actual savings depend on your electricity rate, system size, local sun hours, and how much of your usage the system covers. Higher electricity rates mean larger savings.
What is the typical solar panel payback period?
The average solar payback period in the US ranges from 6 to 12 years. States with high electricity rates like California, Hawaii, and Massachusetts tend to have shorter payback periods (5–8 years), while states with low rates like Louisiana may see payback periods of 12–14 years.
Is there a federal tax credit for solar panels in 2026?
The federal Residential Clean Energy Credit (Section 25D) offered a 30% tax credit through 2025. Under legislation signed in 2025, this credit was eliminated for new installs from 2026 onward. Check your state's DSIRE database for available state and local incentives that may still apply in your area.
How do I calculate how many solar panels I need?
Divide your annual kWh usage by your local peak sun hours and by 365 to get the system size in kW needed. A typical home using 10,500 kWh per year in a 5-sun-hour region needs roughly a 5.75 kW system. At 400W per panel, that is about 15 panels, covering roughly 300 sq ft of roof space.
What affects solar panel performance and savings?
Key factors include local peak sun hours, roof angle and orientation, shading from trees or buildings, panel efficiency, inverter losses, and temperature. A well-positioned south-facing roof with minimal shading generates the most power. Most systems operate at 75–85% of their rated capacity once all real-world losses are accounted for.
Do solar panels increase home value?
Yes. Studies indicate solar installations typically increase home value by $15,000 to $20,000 for an average 6 kW system. However, this varies by market and whether the system is owned outright or leased. Owned systems add more value than leased ones since they transfer to the buyer at no extra cost.
What is a good ROI for solar panels?
A 25-year ROI of 100–200% is considered a solid solar investment, meaning you get 2–3 times your initial investment back in lifetime savings. High-electricity-rate states can see ROIs above 300%. Any payback period under 10 years is generally considered a strong return on investment.