The renewable energy savings calculator estimates solar panel electricity production, annual savings, payback period, and lifetime CO2 reduction for your home. Solar production depends on roof area, panel efficiency, and your location's sun hours.
Solar System Details
Estimates assume US average grid (0.38 kg CO2/kWh). Actual savings vary by location and utility rates.
How to Calculate Solar Panel Savings
Enter your available roof area, local sun hours, panel efficiency, and electricity rate. The solar savings calculator estimates annual production, dollar savings, payback period, and 25-year CO2 reduction.
Finding Your Sun Hours
Peak sun hours measure the average daily solar irradiance equivalent to full sun (1,000 W/m²). Check NREL's PVWatts tool for precise local data. As a guide: Phoenix gets 6.5 hrs, Los Angeles 5.5 hrs, New York 4.3 hrs, Seattle 3.5 hrs. More sun hours = more production per panel.
Tax Credits and Incentives
The federal Investment Tax Credit (ITC) in 2026 is 30% of installation cost. Many states add additional credits or rebates. Utility net metering policies affect how much you earn for excess electricity exported to the grid. Enter the combined federal + state incentive amount for the most accurate payback calculation.
FAQ
Is this solar savings calculator free?
Yes, completely free with no account required. All calculations run in your browser.
How many kWh does a solar panel produce per year?
A standard 400W solar panel produces 400-600 kWh per year in the US, depending on location. The US average solar irradiance is about 4.5 peak sun hours per day. A 10-panel (4kW) system produces roughly 4,800-6,000 kWh/year — covering 40-60% of the average US household's electricity use.
What is the typical payback period for solar panels?
In the US, the typical payback period is 6-10 years after federal tax credits (30% ITC in 2026). States like California, Arizona, and Texas with high sun and electricity rates see payback in 5-7 years. Cloudy states like Washington or Michigan may see 9-12 years. After payback, electricity is essentially free for the remaining 15+ year panel life.
How much CO2 do solar panels save?
The US average grid emits 0.38 kg CO2 per kWh. A 4kW system producing 5,200 kWh/year saves about 2 tonnes CO2 annually. Over a 25-year panel lifetime, that's 50 tonnes CO2 avoided. Manufacturing the panels produces 1-2 tonnes CO2, giving a carbon payback of 1-2 years.
Does this support metric and imperial?
Yes. Enter roof area in square feet or square meters. Electricity production is shown in kWh (universal standard). Costs can be entered in any currency — the calculator uses your local electricity rate.