We’ve all heard about Tesla’s sexy (if we can use that word about batteries) Powerwall home solar batteries. They look flash and they have some great PR. And recently South Australia partnered with Tesla to build Australia’s largest solar farm:
“The Tesla big battery in South Australia has already taken a 55 per cent share in the state’s frequency and ancillary services market, and lowered prices in that market by 90 per cent, new data has shown.”
And this success has led to SA’s interest in more solar farms as well as other state’s taking note and building their own solar farms like this one in the Mallee district of Victoria.
But, what do solar batteries actually do, how can they benefit an individual home and are they worth the investment?
What is a solar battery?
A solar battery is typically a lithium ion, rechargeable battery that can be added to a solar energy system. The solar energy system converts solar rays from a DC energy into electricity as AC power and it’s either directed to your home for energy consumption or it can be sent to your solar battery where it can be stored for use at another time.
(Lithium has a long life cycle, the batteries are safe and stable and don’t require cooling or venting systems.)
How does a solar battery help?
Most solar energy systems on homes are grid-based. This means that a home can generate its energy via a solar energy system and consume the battery’s stored energy if the sun is not shining, or if demand increases and if the home depletes the battery’s energy they can then rely on the external energy grid for their energy needs, meaning the home is never cut off from energy but the home is able to supply most, if not all of its own energy needs.
If your solar energy system is generating more energy than your property is able to use (during daylights hours) then it can save that excess generation in your solar battery. Or, if you find your property has higher energy demands during non-daylight hours, you can adjust your energy consumption so that your battery supplies your home’s energy during the evening. A battery can also help support energy needs during peak demands, like very hot days (when you’ve cranked up your AC) or if there is a blackout in your area; your home won’t have to go without energy.
If you have a full battery and your home is generating more energy than you’re using you can also export excess energy to the grid and get paid for that energy supply with feed-in-tariffs. These tariffs will vary by retailer, but here are the 2019 rates.
How expensive are solar batteries?
Not all solar energy systems come with a battery, in fact, most don’t – it’s an additional bolt-on to a solar energy system. Most of our current solar installations don’t include a battery (yet!) as batteries do have a high price tag, for now, and they can be added retroactively to hybrid, or battery-ready solar energy systems so many customers opt to add one later when solar battery prices decrease or when they have additional resources to invest in their solar energy system.
Solar batteries are still an emerging market and because of this prices are coming down over time. 2017 was a record year for solar installations and 2018 beat that record. Thanks to solar incentives around Victoria like the 50% off solar rebate we can expect 2019 to smash 2018’s record. Thanks to this increasing demand for solar energy systems, the demand for batteries is also increasing and the price of the products are falling.
“It’s estimated that lithium-ion battery prices decreased by 80% between 2010 and 2018”.
Should I install a battery?
Deciding whether you should install a battery can be a personal decision and will come down to if the return on investment is there. We can help you assess whether your home would benefit from a battery, how much it would cost and if it would be better for you to wait before installing one. Waiting for solar battery prices to come down in price does not mean you should delay installing a solar energy system. As we mentioned earlier in this post, you can install a solar energy system now and add a battery later. And as we’ve talked about before, there’s never been a better time than right now to install solar.
