Solar Payback Calculators

Solar Loan Calculator

This calculator shows you how much you would pay (and then save), over time, if you installed solar electricity in your home and financed it with a personal loan.

The calculator works out the loan repayments to cover the cost of your solar system but subtracts your monthly electricity bill savings.

A red bar on the graph shows the net cost for that month.

A green bar shows net savings.

You'll see that the net cost reduces over time. This is because electricity prices will go up, but your repayments will stay the same. Once your repayments are finished you can see that you are making pure savings every month.

I've made 3 videos that show you how to use the calculators and interpret the results. You can watch them here

Your State:

This determines your Feed In Tariff and estimated power output. (You can override the numbers in Advanced Options)

System Size:

This determines approximate values for the next 2 boxes (cost and electricity output). You can override these with more accurate numbers if you have the information to hand.

Out-of-pocket cost for the quoted solar system.
$

Enter the price you will pay after you have claimed all rebates and RECs.

Upfront Payments (optional)
$

Enter any upfront payment that you would like to make.

Annual Solar System output in kWh

This is the electricity output of the system as estimated in your quotation.

Price per kWh you currently pay for electricity
cents

You can find this on your bill. 19c per kWh is typical.

Show Advanced Options
Annual bill inflation %	Enter approximate annual bill increase (3% is optimistic, 7% is pessimistic)
Feed In Tariff % at cents per kWh	The percentage of electricity generated that you estimate will earn the FIT rate.
Feed In Tariff Duration years	Feed In Tariff Duration
System Degregation % per annum	All systems degrade over time, good ones at less then 0.5%, cheaper ones at closer to 1%
Assume Inverter Replacement $ after years	Generally, good inverters should last about 20 years
Include Opportunity Cost % per annum	This is the cost of money that could have been invested instead

Cost/savings per month:

Interest rate
%

Term
years

Over years:		$
	b) Total Electricity Savings:	$
		$
	Payback:

How to read the graph: the bars show the cost/savings over time of owning the quoted solar system. It is your electricity bill savings minus the loan repayments to pay for the system. Hover your mouse over a month to see the cost/savings.