Power your home the ECO -smart way by installing solar batteries
How home battery systems make sense of solar energy production in the wet and windy UK
Adding storage batteries to solar panels means you can stockpile power for winter
Everyone wants to be green, but solar panels don’t seem that reliable an energy source when you’re looking out of the window in dreary winter. Indeed, solar energy in the UK has always been seen as something of a fair-weather friend. However, this has all changed with the introduction of affordable home battery energy storage systems. These are designed to collect any spare solar power being produced, storing it ready for when it’s needed, such as in winter.
Before this, energy generated by solar panel systems could only be used at the time it was created, during sunlight hours, which is the time most households have the least demand for energy. These new home storage batteries can be thought of as basically very large lithium-ion phone batteries, and can help you store up to a whole day’s electricity (roughly 13.5Kw for a two-bedroom home), ready for when you need it most.
There are a wide range of home storage battery choices out there from brand-new startups to known industry names like LG, so when it comes to investing in a battery it’s important to do your research. You need a battery that matches your supply needs – there’s no point buying a large capacity battery if you aren’t producing enough to charge it, and there’s no point buying smaller batteries that can’t store the amount of energy being generated.
Most batteries are stackable, as in you can add more batteries in series to store extra power, but it’s important to note that, quite often, batteries from different suppliers will not work together. It’s also important to look at the lifetime guarantee of the battery and its electricity retention (how long and how efficiently it can keep recharging and dispensing energy).
Leading the field in terms of capacity (and value) is the well-known Tesla Powerwall 2 (£6,200, tesla.com). The Powerwall 2 battery is incredibly heavy, and stands at just over one metre tall, but simple to fit for trained engineers. The solar panels, invertor and battery installation typically takes a day, and you’ll be without power for part of that day. The battery itself can be fitted in a garage, but the Powerwall 2 (and several other options) are weatherproof, so fine to mount outside.
Note that most of these batteries are designed to integrate with the grid, so they won’t come to the rescue during a power cut – for safety reasons you’ll be cut off, just like your neighbours. It is possible to convert the house to be completely off grid, but this is a more complicated and expensive procedure. Remember though, up until 31 March 2019 you can sign up for the Feed-In-Tariff scheme, introduced by the UK Government back in 2010, where you’re paid 5.24p for every kWh you export back to the grid.
The flexibility in energy usage enabled by adding storage batteries to solar panels is a no-brainer. The Powerwall 2 we installed back in March 2018 (the one our neighbours teased us for because it rained for seven straight days after installation) has made a three-bedroom house containing two adults and two children 76 per cent self-powered since then. Here comes the sun!