Solar Payback Calculators

Solar Payback Calculator

This calculator shows you how much you can expect to save on your electricity bill over the years if you install solar electricity in your home.

It also calculates the payback: i.e. how long it will take you to recoup the investment through your reduced bills.

If your state offers a feed in tariff then you can add that to the savings using the advanced options.

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.

Annual Solar System output in kWh

This is the annual system output 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 in SA.

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

Savings per month in reduced electricity bills:

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

How to read the graph: the bars show the electricity savings in $ over time of the solar system. The savings increase over time because we are assuming that electricity prices will increase over time. Hover your mouse over a month to see the savings for that month.