Opinion: Is the Automotive Industry Driving Self-build Change?

Tech expert Neil Mohr argues why we should look to the motor industry for developments in home energy storage solutions

Make hay while the sun shines’ — in the modern world, with fields full of photovoltaic solar panels, that idiom takes on a whole new meaning. Seeing the sun shining can set off thoughts that packing your home with solar panels would be an ideal investment — and it is. The annoyance is that Feed-in Tariffs (Fits) – the amount of money you’re paid for generating electricity – aren’t quite what they used to be.

In the Fits heyday of 2011 you could expect 46p/kwh. This was understandably slashed to 24p, but the current tariff for generation is now a woeful 4.01p, with an export payment – for electricity sent out to the grid – of 5.24p/kwh. A bit cheeky when a well-known British utility charges you around 15p/kwh for that same sparky electricity coming in from the grid.

So what’s the answer for selfbuilders and renovators? Are you left at the whim of the ‘Big Six’ electricity providers, which seem to happily pay you 10p less than they charge you for the same juice? The encouraging answer is no, there is a solution and it comes from the car industry.

You’ve likely heard of Tesla — it’s the car manufacturer famous for its cutting-edge battery-powered vehicles, and brainchild of the billionaire Elon Musk. Tesla has spent billions of dollars developing car and lithium-ion battery technology and has since realised its new technology has applications in the home. So the Tesla Powerwall was born.

For those looking to add it to their self-build or renovation project, the 13.5kwh battery ‘pack’ costs just shy of £6,000 fully installed and, when coupled with a solar array, has the potential (at times) to make a home entirely self-sufficient for electrical energy. The Powerwall can be charged during the day, when there’s low demand on the solar panels, then during the evening offer enough capacity to power your home’s entertainment, lighting, heating, appliances and charge your car. Of course there’s also a litany of smartphone apps, graphs and controls to help you monitor and control your Powerwall use.

It should come as no surprise that Tesla isn’t the only car manufacturer to be getting in on the home-power harvest. If a company is developing battery-powered cars, it’s likely that it’s working on a home storage solution too.

Nissan Energy Solar is now offering Xstorage Home in the UK. It has an option that uses recycled car battery packs and can be installed, including solar panel installation, for around £7,700. Though the battery – depending on the chosen model – starts at the smaller capacity of 4.2kwh.

Mercedes Benz has its at-home 2.5kwh pack that can be stacked to provide up to 20kwh of storage, but this isn’t currently available in the UK and the pricing is unknown, though in the US these start at $5,000 going up to $13,000 with installation. In a similar situation, BMW also claims to be working on a home storage system based on recycled car batteries, taken from its BMW i3, with 22kwh and 33kwh capacities — though, again, there’s currently no timeline or pricing for the UK.

Of course, not all the companies planning home battery solutions are car manufacturers. The battery arm of LG has launched its own LG Chem RESU range in the UK, with capacities from 2.9kwh to 9.3kwh and prices ranging from around £2,200 up to £5,100.

Home solar is, like all good investments, a long-term one, but it’s one that’s paying off for the UK. Solar generation is pushing 25% of total demand in the UK on sunny days*. It’s helping the UK produce less CO than it did since the

2 1890s**, pushing us far ahead of our Kyoto commitments and ensuring the UK leads the world as a low-carbon economy.

For self-builders looking to take maximum advantage from Fits and to decrease their reliance on central power networks, home battery storage is the next frontier — with the change being driven by the car industry.

“Are self-builders to be left at the whim of the ‘Big Six’, which seem to happily pay 10p less than they charge for the same electricity?”