Home batteries and solar storage systems allow extra electricity produced by solar panels to be saved for later use. This is especially useful on overcast days or when several appliances are in use when a household's electricity use exceeds the electricity produced by the solar system.
Batteries can also protect against blackouts and boost a household's solar energy utilisation from 10% to as much as 90%.
How does solar storage work in combination with a solar system?
Suppose you have a solar system that generates electricity. So if you watch TV, use a washing machine or a dishwasher, that’s where the electricity goes.
Sometimes, your house consumption overall during the day will be higher than what your solar system can generate, for instance, on a very cloudy day when you have several appliances running simultaneously, the dishwasher, dryer, air con etc.
That would result in more consumption than a medium-sized system can generate. So, in that case, you pull additional energy that you may need out of the grid.
In this specific sample, your house has a consumption of 6 kW/h at the time. However, your system generates three kilowatt hours, so to satisfy the six kW/h demand, three additional kilowatt-hours need to be supplied by the grid.
If you have a minor consumption for a while, your PV system will supply everything you need and potentially a little extra. If you don’t have a home battery storage system, that spare electricity gets exported back into the grid.
Getting the feed-in-tariff
Unfortunately, feed-in tariff payments have reduced significantly compared to the past.
Ten years ago, the feed-in tariff in some areas of Australia was $0.60. Many energy retailers have reduced the feed-in tax to 5, 8, or 10 cents, which isn’t great. You are buying it maybe for 25 to 30 cents a kilowatt hour and as high as 50 cents if you have the time of day metering, and then you are exporting it and giving it to them for 6 to 10 cents. As a result, the energy retailers are making a very high profit margin on that arrangement.
So what can you do to make the most of your solar system?
One of the options available is to not send that electricity out of the house and look for other ways to use it on your premises.
When a PV system produces excess electricity, using this excess for a hot water tank is a viable option. Some products will then send that spare electricity your system generates into the electric hot water tank to heat your water.
But home battery storage is the most obvious solution for any spare electricity. Unfortunately, a home battery nowadays still takes quite a few years to pay itself back, but it can give you excellent blackout protection.
Batteries enable you to contain your solar energy for later use rather than exporting it for an affordable payment and then buying electricity from the grid at a much higher rate later. This means that a typical solar residence, with the help of a home battery, could increase its solar usage by as much as 90 per cent through self-consumption.
So, the answer is that your extra electricity doesn’t just go somewhere magically; it has to go to the grid, into a hot water system, or a home storage battery.