# How Our Solar Savings Calculators Are Programmed

## Programing for Go Solar Group's Savings Calculators

Solar calculators can't account for every possible variable, which is why there are so many solar calculators. At Go Solar Group, we have programmed our solar savings calculators with specifics that match the products we use and the areas we serve.

Choosing a solar calculator that measures factors that the customer is looking at is imperative for them to find an accurate estimate. Being too general is why calculators like Google's Project Sunroof calculator falls short. While this calculator helps customers determine whether their home is a good fit for solar, it doesn't give them savings, financing, or pricing specific to the solar companies they are considering.

To create an accurate estimate for a solar array without looking at the specifics of the home, Go Solar Group looks at the cost of its solar panel installations, the federal and state rebates, the loans our partners offer, and the increase rate for the utilities in the areas we serve.

### The Cost of an Array

To configure the cost of a solar array, Go Solar Group's calculator looks at the watts generated by the panels used. It then uses the estimated monthly bill that the customer has put into the calculator to determine how many solar panels are necessary to meet the usage needs of the home.

The monthly bill estimate that the customer puts into the calculator equals a certain amount of watts. The local utility rates give an idea of how much usage an average bill equals.

### How Rebates are Calculated

The calculator subtracts the current federal solar tax credit (ITC) and any state tax credits from the cost of the solar array.

### Solar Loans Through Go Solar Group

Go Solar Group also offers financing options through its loan partners. The terms and rates of these loans are input into this calculator.

### Why Go Solar Group Adds the Electric Increase Rate

The average increase rate for utilities in the state gives an idea of how much utility-generated electricity would cost the customer over the life of a solar array. These rates allow the calculator to determine the comparative cost of solar and generate estimated savings.

## How the Terms are Grouped

Another thing to consider when looking at a solar calculator is how the calculator calculates different terms. The solar savings calculators at Go Solar Group looks at system cost, total cost, the federal rebate, state rebates, total electric cost, electric annual increase and purchasing options. Together all these grouped terms allow the Go Solar Group solar savings calculator to generate a reliable solar savings estimate.

###### $system_cost = $cost_matrix[$location_area][$electric_bill][**‘cost’**];

###### $total_cost = $system_cost; //Get the cost from the Matrix

###### $federal_rebate = $total_cost * $federal_rebate_amount;

###### $state_rebate = calculate_state_rebate ($areas, $cost_matrix, $location_area, $electric_bill);

###### //Figure out what the cost will be over 20 Years with standard increases.

###### $total_electric_cost = *round*(calculate_20_year_electric_bill ($increase_rate, $location_area, $electric_bill), 2);

###### $electric_annual_increase = $increase_rate[$location_area];

###### $options[**‘cash’**][**‘net_cost’**] = *round*($total_cost – $federal_rebate – $state_rebate, 2);

###### $options[**‘cash’**][**‘net_savings’**] = *round*($total_electric_cost – $options[**‘cash’**][**‘net_cost’**], 2);

###### $options[**‘cash’**][**‘payback_period’**] = *round*(calculate_cash_payback_period ($options[**‘cash’**][**‘net_cost’**], $electric_annual_increase, $electric_bill), 1);