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Calculate How Much Power You Need

You can use these solar calculators to estimate the size and the cost of the solar panel array needed for your home energy usage. Ideally, you will know your total kilo-watt hours (kWh) used for the past 12 months or the average monthly kWh used each month. Check your electric bills or contact your local utility for your kWh used.The cost and size of a solar panel system depends on your current and future energy consumption, your location, the types of solar panels and components to be installed, and the availability of rebates and incentives.

Monthly Electric Bill Estimate

Actual Energy Use Quote

Select your monthly electric bill for a general online estimate of how much solar power your need

Use this Solar Calculator to determine a precise system size for your actual energy use. Refer to the definitions below for explanation.

1. Your kWh used per year: kWh/year[?]
2. Solar Hours per Day (see map below):
3. % of Electricity Bill to Offset: %

Solar Array Size Estimate: kW [?]

4. Estimated Cost per Watt [?]

Solar Array Cost Estimate: $

Find Solar Kits

Once you know how many kilowatts kW you need, choose your size to see solar kits for sale at Free Clean Solar. These pre-engineered systems qualify for tax credits and rebates. We can also custom design a solar system just for you!



Solar Calculator Definitions

  1. kWh per Year - Check your electric bill or ask your utility provider for your kilowatt hours or 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.
    Solar Map Sun Hours per Day
    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 U.S. Department of Energy, National Renewable Energy Laboratory (NREL) 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.

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