You are here: Home > Learning Center > How to Buy Solar Panels > Solar Energy Assessment

Simple Steps To Perform A Solar Energy Assessment

An energy assessment is simply an evaluation of how much energy you use today and a calculation of how much solar power generation is required to meet the needs of your household or business. You can figure this out for yourself by answering three basic questions.

How Much Utility Energy Do I Use? Question 1: How Much Utility Energy Do I Use

How Much Solar Energy Do I Need?Question 2: How Much Solar Energy Do I Need

How Many Watts of Solar Power Do I Need?

We will use the calculator below to estimate how many kilowatts (kW) of solar power are needed to generate your energy. First, enter the yearly kWh from the electric bill or off-grid load estimate. Then enter the daily Sun Hours for your location. Scroll down to see the color-coded map to find your location. Next, enter the % of your electricity bill to offset with solar panels. Click "Calculate" to see your DC watt size.

Once you know the amount of watts, then the number of solar panels can be determined. For example, if you need 1,000 watts or 1 kW of power, and you select 250 watt PV modules, then you would need four (4) solar panels.

Remember, you decide how much solar to get based on the need, available space and budget. There is no rule that you have to offset 100% of current energy use. Sometimes it makes better dollars and sense to start small and add-on later as prices are expected to decline. If you are a high volume utility user, you may be paying a higher rate for the larger consumption. Installing a smaller system to offset just 25% of your energy use may reduce the monthly power bill by 50%.

Solar Power Calculator

1. Your kWh used per year: kWh/year[?]
2. Solar Hours per Day: See map below[?]
3. % of Electricity Bill: % [?]

Solar Array Size: kW [?]

Step 2: Site Assessment      Step 3: Equipment Selection      Step 4: Pricing and Quotes      Find Solar Kits

Sort By:
Page of 1
solar system design
Solar System Design
Custom Prepared in 1 to 3 Weeks
Your Price: $449.00


Receive a custom permit design for a solar panel system prepared by an experienced technician. This personalized solar design helps you to make an informed, unbiased decision to find the best system at the lowest cost. Understand your options for residential or commercial modules, on-grid or off-grid, backup systems, rooftop or ground mounting. Once complete with a qualifying system order, the solar design can be converted into a large format plan blueprint to use when applying for building permits, utility or HOA approval. See specifications for what's included. TERMS & CONDITIONS Applies to existing, single-family, grid-tied residence up to 30kW. For off-grid battery storage systems, sizes larger than 30kW, commercial buildings, or new construction, please choose plan upgrade. Final plans provided upon valid system order; plans are not sold without a system order. Design fee will be credited toward valid system order. Design fee will be forfeited without system order. Order online or PHONE 888-498-3331 more info

Solar Power Map of the United States

Find your Solar Hours per Day using the color-coding on this map. Enter the value for your location into 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.

Get a FREE solar panel evaluation with the latest prices and rebates   Start Here