Falling prices for your surplus solar electricity means you should reassess your appliance usage.

The approach of cooler months and shorter days means more of us will be indoors longer, consuming more energy for our heating, lighting and hot water.

With one in five Australian households now having solar systems on their roof and hundreds of thousands set to join them in 2015, home owners should consider how to get the best return on their investment.

“Back in 2003, the cost of installing solar energy was $10 per watt produced, however by 2014 this has fallen to just $1.00 per watt”, said Dr Stephen Bygrave of Energy Freedom.

“When calculating an investment in solar energy, many people factored in the price they would be paid for exporting surplus electricity back into the grid. While selling power back to the grid was attractive a few years ago, the current situation is quite different.

“While electricity prices from the grid have risen to around 33 cents per kilowatt hour, today you will receive only eight cents per kilowatt hour for any excess power you sell to the grid. This low ‘buy-back’ price means you have a financial advantage by using your own   generated power and avoiding use of appliances which are dependent on costly gas”, Dr Bygrave said.

What should you do for the best value from your investment?

For a start, using your reverse cycle air-conditioning system for heating instead of gas. Ducted gas space heating system has an overall efficiency of just 29.4 percent compared with 391 percent efficiency for a modern split-system heat pump.

The bottom line is, changing from gas to electric reverse cycle heating will save around 60 percent on your heating bill. Users of their own solar-generated power will make even greater savings.

“Depending on your feed-in tariff, you may change your usage times and upgrade your appliances to save thousands on your energy bills. Changing gas hot water to an electric heat pump hot water system running off your excess solar will save you on average $320 a year, according to the University of Melbourne’s Energy Institute