Submitted by Taylah.Horsten on Tue, 15/11/2022 - 09:59
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Historically, generating excess energy from your rooftop solar system was financially beneficial as you could sell this excess energy back to the grid at a high rate. As an example, for systems installed before July 2011 in Western Australia, the excess electricity could be sold back to the grid for up to 47 cents per kWh exported. This meant you would have little to nothing to pay on your bills. Nowadays, the going rate for feed-in tariffs are as low as 2.5 cents, yet you are paying around 30 cents per kWh to buy that energy back in the evenings when your panels aren’t producing.

With feed-in tariff rates so low and energy prices going up, it’s more important than ever to ensure you are making the most of the electricity produced by your solar system.

How can I maximise the use of my PV generated electricity?

The simple answer to this is storage! The two most common ideas of storage are a solar battery system or an electric car. While these are both fantastic options, they can be quite costly. A more economical energy storage option that also has a lower environmental footprint is the iStore hot water heat pump.

The iStore improves your home’s energy efficiency by extracting energy from the air around it to supply hot water to your home. It uses similar technology to your household fridge/freezer, except in reverse. Instead of pushing heat out of the freezer to keep it cold, the iStore transfers heat into water, making it hot. According to the Melbourne Energy Institute and the ‘Beyond Zero Emissions Report: 2013’ this method of heating water is 80% more efficient than conventional electric or gas hot water systems.

By timing your iStore to run during the day when your solar power system is most productive, you are storing your excess energy like a thermal battery to use later in the day, instead of sending it to the grid for a measly 2.5 cents! In a 4-hour heating cycle, the iStore consumes only 2 - 4 kWh of energy, so if you run the unit when solar production is high, this gives you the potential to have free hot water all year round!

For the average Western Australian household, hot water accounts for around a quarter of your household energy costs. The iStore uses about two-thirds less energy compared to conventional electric or gas storage systems, while also reducing CO2 emissions by 4 tonnes. Installing an iStore could save you up to $1,000* per year on your electricity or gas bills.





*Savings are based upon the running costs of an electric storage or 3-star gas storage hot water systems for a family of 4 consuming 200 litres per day for one year when compared to an iStore 270L with PV solar contribution. Tariffs based on WA pricing, $0.25 per kWh for electricity, Natural Gas price of $0.0351 c/MJ & LPG price of 1.25 $/L. Actual savings may vary on household usage, solar power system and climate conditions.


In today’s market, using the iStore is a much more affordable option to a battery. You are paying less by consuming less gas or electricity, while making better use of your excess solar power for hot water. It is a win for the environment and your back pocket!


To find out more information on our iStore units, or how you can use your iStore unit to save, give us a call on 1300 745 409.