Solar Calculator
Solar panels generate electricity using photovoltaic technologies that capture the energy in sunlight. Most parts of the United States have abundant solar resources to power the average home or business. Use this solar calculator to estimate the size and the cost of the solar panel array needed for your energy usage.
Before investing, however, you should get a free home solar evaluation to determine your site's solar resources. Even if it reveals lower or moderate resources, solar power could still be viable financially, especially with attractive financial incentives, tax credits or utility rebates for solar panels.
Request a FREE solar evaluation from solar installation pros in your area.
Enter information to estimate your solar array size and solar cost.
Refer to the definitions below for explanation.
1. kWh per Year
Check your electric bill or ask your utility provider for your kWh used in the past year.
2. Solar Hours per Day
Find your Solar Hours per day on this map using the color-code for your location. Enter the value for kWh/day in the solar calculator.
Use this link for a more detailed solar map. The solar map uses insolation, a measure of solar radiation energy received on a given surface area in a given time. This is typically measured in kilo-watt hours per square meter per day (kWh/m2/day). The map shows the average daily total solar radiation throughout the United States. The National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy developed it.
3. Electric Bill Offset
The percentage amount you wan to reduce your monthly electric bill. Do you want to cut your electric bill by 20%, 50% or 100%? It will cost less upfront to start with a smaller system, but you will still save money every month.
4. Estimated Cost per Watt
Enter a value in this field to estimate the cost of solar panels for the size of your estimated solar array. Cost per watt will vary depending on the system size, solar manufacturer, labor costs and location. Generally, larger 50 kW or 100 kW solar panel systems will have a lower cost per watt than smaller 2 kW or 10 kW systems due to economies of scale and buying power.
