Last updated: March 2026
What Is the Solar Savings Calculator?
This solar savings calculator estimates how much money you can save by installing solar panels on your home. Enter your monthly electric bill, select your state, and provide basic roof information to get a personalized estimate of system size, installation cost, payback period, and total savings over 25 years.
The calculator uses real state-level data including average peak sun hours and electricity rates for all 50 states plus DC. It factors in the 30% federal Investment Tax Credit, panel degradation over time, and annual electricity price increases of 3% to give you a realistic long-term projection.
The average American household spends about $1,800 per year on electricity. With solar panels, most homeowners can eliminate 80-100% of that bill and break even on their investment within 6-12 years. Over 25 years, total savings typically range from $20,000 to $90,000 depending on your location and electricity usage.
How to Calculate Solar Savings
Solar savings calculations start with your monthly electricity usage. We divide your bill by your state's average electricity rate to determine how many kilowatt-hours (kWh) you use. That annual usage tells us how large a solar system you need.
The required system size in kilowatts (kW) depends on your state's peak sun hours, roof direction, and shading. A south-facing roof in Arizona needs fewer panels than an east-facing roof in Michigan to produce the same energy. The calculator accounts for an 80% system efficiency factor that covers inverter losses, wiring, temperature effects, and other real-world performance factors.
Installation costs average $3.00 per watt in 2026, meaning a 7 kW system costs about $21,000 before incentives. The federal 30% tax credit brings that to $14,700. Your payback period is calculated by determining when cumulative electricity savings exceed your net system cost, accounting for 3% annual electricity price increases and 0.5% annual panel degradation.
The environmental impact is calculated using the EPA's average of 0.92 lbs of CO2 per kWh for grid electricity. Over 25 years, a typical residential solar system offsets 150,000-300,000 lbs of CO2 — equivalent to planting hundreds of trees or taking a car off the road for decades.
Frequently Asked Questions
How much do solar panels cost in 2026?
The average cost of a residential solar panel system in 2026 is about $3.00 per watt before incentives. For a typical 8 kW system, that's roughly $24,000 before the federal tax credit. After the 30% federal Investment Tax Credit (ITC), the net cost drops to about $16,800. Prices vary by state, installer, and equipment quality.
What is the 30% federal solar tax credit?
The federal Investment Tax Credit (ITC) allows you to deduct 30% of your solar installation cost from your federal taxes. This credit is available through 2032 at the full 30% rate, dropping to 26% in 2033 and 22% in 2034. It applies to the total system cost including installation labor, and can be carried forward to future tax years if you can't use it all at once.
How long does it take for solar panels to pay for themselves?
The typical payback period for residential solar is 6 to 12 years, depending on your electricity rate, sun exposure, and system cost. States with high electricity rates like California, Massachusetts, and Hawaii tend to have shorter payback periods (5-7 years). After payback, solar panels generate essentially free electricity for the remaining 15-20 years of their lifespan.
Does roof direction affect solar panel efficiency?
Yes, significantly. South-facing roofs receive the most sunlight in the Northern Hemisphere and produce 100% of potential output. Southwest and southeast orientations produce about 92% as much. East and west-facing roofs produce around 82%. Flat roofs work well at about 90% efficiency since panels can be tilted to optimize angle. North-facing roofs are generally not recommended for solar.
How long do solar panels last?
Modern solar panels are warrantied for 25 years but typically last 30-35 years or more. Panel output degrades about 0.5% per year, so after 25 years they still produce roughly 87.5% of their original output. Inverters usually need replacement once during the system's lifetime (around year 12-15), costing $1,000-$2,500.
Do solar panels work on cloudy days?
Yes, solar panels still produce electricity on cloudy days, just at reduced capacity. Panels typically produce 10-25% of their rated output on overcast days. This is already factored into the peak sun hours data for each state — states like Washington and Oregon have lower sun hours that account for their cloudier climates.