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This calculator is designed to help ACT households who are considering whether to install solar panels.

When you enter some simple information, the tool estimates how much you could save on electricity costs each year by installing a solar system. It also estimates how many years it would take you to break even on the cost of installing a solar system. This is called the “pay back period”.

If you own a home in the ACT, you may be eligible for a zero interest loan through the ACT Sustainable Household Scheme and/or a rebate through the ACT Home Energy Support Program. This may help you to meet the upfront cost of installing a solar system and other products to improve your home’s energy efficiency.

To get your estimate of likely savings and pay back period, fill out the boxes below.

Each time you enter a different value in the input boxes, the results will update below.

If you would like to save the results, please use the print button below or your browser’s print screen and save them as a PDF.

Please note the disclaimer below.

To find other ways to reduce your energy costs, try our free Home Energy Assessment webtool.

If you would like more advice on installing a solar system on your home, please email

Input tips

Electricity use

Energy providers are required to provide you with information about your average daily electricity use. You can find this information on a recent electricity bill, usually in a graph on the second page.

Electricity cost

The cost per kWh can be found on your electricity bill. If you have several charges per kWh on your bill (e.g. peak, off-peak, shoulder) you can use the calculator’s default value of 0.224 (22.4 cents per kWh).

Feed-in tariff

When your solar panels generate more electricity than you are using in your home, the excess power is fed back into the grid. Your electricity provider may pay you for this excess energy. Current feed-in tariffs are listed on electricity retailers’ websites. If you are not certain what feed-in tariff your preferred electricity retailer is currently offering, you can use the calculator’s default value of 0.06 (6 cents per kWh).

System size

System size describes the number of solar panels you plan to install on your roof and the amount of electricity they can produce. The larger the system size, the more electricity you can produce.

Typical system sizes in Australia are 5.5 kW (approximately 15 panels), 6.6 kW (approximately 20 panels) and 10 kW (approximately 35 panels).

If you are eligible for the ACT Home Energy Support Program solar rebate, the eligible system size is between 5.5 kW and 6.6 kW. If you do not know which system size you are considering, you can use the calculator’s default of 6.6 kW.

Description of current electricity use pattern

Based on the description you choose, the calculator estimates the percentage of your solar-generated electricity that you will use rather than export. “Usually not at home…” sets a self-consumption value of 20%, and the next three options set self-consumption values of 40%, 60% and 80%. The average household that does not deliberately shift their electricity usage to daytime is expected to have a self-consumption value of 30% to 40%.


To find out whether you are eligible for the rebate of up to $2500 please see the ACT Home Energy Support Program.


This calculator gives only an indicative estimate of the potential savings that a household might achieve by installing solar panels in the ACT. The results are based on the user’s input and several assumptions that may not be accurate for the user. This calculator does not account for additional factors such as system degradation, maintenance costs, changes in electricity tariffs or feed-in tariffs or inflation. It is intended only to assist households to consider whether they would like to investigate installing solar panels. It is not intended to replace professional advice.

No Warranty Express or Implied

The Territory does not warrant the accuracy or completeness of the calculator and accepts no responsibility whatsoever for any reliance on the estimation provided for any purpose whatsoever.

Disclaimer Applies

The ACT Government Disclaimer applies to the use of this calculator. The Disclaimer can be accessed at

Assumptions used in calculating results

The calculator makes the following assumptions based on average data for the ACT. Each household differs so the results are estimates only.

  1. Each kW of solar system generates on average 4.3 kWh electricity per day in the ACT. This is the estimate for Canberra on the YourHome website.
  2. The self-consumption of solar-generated electricity ranges is assumed to be 20%, 40%, 60% or 80%, depending on the answer given to the question “What best describes your current electricity use?”
  3. The cost of an installed solar system is assumed to be $1200 per kW. This is based on average pricing data for systems sold under the ACT Sustainable Household Scheme in 2021-22.
  4. For the purpose of this calculator, the rebate is assumed to be exactly $2500, as this is the expected value of most rebates under the Home Energy Support Program.
  5. The estimated cost saving with solar is calculated as the difference between how much the household is estimated to pay now for electricity and how much the household is estimated to pay after a solar system is installed.
  6. Changes to your home’s electricity infrastructure may be required when installing larger systems solar systems of 10kW or more. This tool does not take the cost of these changes into account.