Getting Started

Answer the two questions below to find out what information you need to start.

I am interested in:

Choose the type of system you are interested in:

Information to Gather


The calculator uses default values wherever possible, but we suggest you gather the following for more accurate results.

  • Access your electricity billing history online or via a phone call to your electric utility. Add up all of your kilowatt­-hours (kWh) from the last 12 months. Alternatively, simply multiply the kWh from your last bill by 12. (Note: this method will not work for all­-electric homes.)
  • If you plan to finance all or part of your PV system, identify a loan interest rate and term (years).
  • Check with your utility company about rebates or incentives for solar electricity generation. This includes the total dollar limit on rebates and the number of years you would be paid with an incentive.
  • If you are interested in leasing a PV system, contact a solar company for an estimate or quote. Try to get the down payment, Year 1 monthly payment, and annual rate increase of the lease.
  • Estimate or measure the square footage of the roof space you would use to host a PV system.
  • Evaluate the location you plan to use. Determine which directions the panels could face to avoid slope or shade.