Using solar battery electricity from your home energy storage system can be cheaper per kilowatt-hour than using grid power, according to Choice.
The consumer advocate says a large enough solar array and battery storage system can be a cheaper option, depending on time of day and the feed-in tariff (FiT) you get from your energy supplier.
Interestingly, Choice concludes that battery storage makes more financial sense for households with a lower feed-in tariff.
Because FiTs are relatively low in most parts of Australia, it can be more cost-effective to divert excess solar energy into your own battery storage. This can then be accessed overnight or at times when the weather is overcast.
According to Choice’s Chris Barnes, solar battery costs continue to fall. Over the next couple of years more people are therefore likely to install energy storage batteries with their solar panels. This will bring them close to the financial tipping point between battery cost and retail power cost.
Solar battery electricity now protected from blackouts
In general, solar batteries disconnect from the electrical grid when a blackout occurs.
This is due to ‘anti-islanding’ protection, which protects electrical workers from power surges from home batteries when they are trying to repair lines on the grid. Your home solar power system is an ‘island’ of power; that is, it’s not controlled by the main distribution network.
However, today’s advanced storage systems provide anti-islanding protection while still keeping your solar panels and battery operating.
The sonnenBatterie Protect 2500 is an add-on device to the sonnenBatterie Eco system. It senses electricity outages in real time, automatically switching to stored battery power.
This offers a convenient off-grid electricity supply to access in emergencies. As Choice points out, you can nominate specific items like fridge, freezer and lighting to receive power by rewiring your home circuits.
The inevitable march of solar battery storage
While battery storage can still be expensive, Choice notes that increasing numbers of people are investing in home battery systems. There is also an increasing trend to make solar PV systems battery-ready.
Choice recommends working through two or three quotes to ensure you get the best and safest deal. Solar retailers and installers accredited by the Clean Energy Council (CEC) offer the latest technology, competitive prices and approved installation.
Advanced products like the Tesla Powerwall 2 offer a comprehensive all-in-one solar battery system with an inbuilt DC-AC inverter, making installation easier and reducing costs.
