What is the one thing we can do to make our home more green?

The obvious answer is simply to ‘consume less’.

But what if you don’t want to spend your life walking from room to room, unplugging laptop chargers and turning off lights? What if a large family of children make a dishwasher and tumble dryer necessities not luxuries?

What if, put simply, you’d like to cut your carbon footprint (and your utility bills), without actually using less electricity?

The answer came to me during a conversation with a friend last week, who works for one of Europe’s biggest private sector employers. I won’t mention the company concerned, but I will share with you with what had persuaded this firm to shift a large part of its investment focus.

Home batteries.

The buzz around home batteries has been growing for months.

Last year Tesla, the electric car company founded by the American billionaire Elon Musk, began to market the Powerwall.

It’s a sleek white box, measuring about 1.3 metres by 80cms. It can be bought for just under £2,000. Or, at least, it can theoretically be bought. The device has proved so popular that you would be lucky to get one by the end of the year.

The numbers involved in all this are enormous.

Deutsche Bank recently estimated that ‘stationary battery storage systems’ for homes and businesses could net Tesla as much as $4.5bn in annual revenue. The company is so confident that home batteries will catch on that it is building an enormous $5bn lithium-ion battery factory in Nevada to meet anticipated demand.

Other companies, including the nameless one my friend works for, are jumping on the bandwagon. Mercedes-Benz plans to sell home batteries, initially just in Germany, from September.

How do they work?

First, they appeal to people who can generate their own renewable energy from solar panels or wind-turbines. At the moment, these people must sell power to energy suppliers, buying it back again at peak times. With a home battery, the power you generate is there to be used by you.

Second, a home battery allows households to take advantage of power companies’ lower tariffs during the night, and use the cheaper, stored energy during peak periods. According to Tesla, by charging itself at 3am instead of during the afternoon, when electricity rates are significantly higher, the battery will slash household electricity bills by 25 per cent.

Third, home batteries bring energy to remote areas. They can also provide back-up power in the event of a black out.

Colin Brown, director of engineering at the Institution of Mechanical Engineers, recently told a British newspaper that home batteries could help the government reduce emissions at time when it was facing being fined by Europe for breaching air pollution levels.

“Without storage you’ve always got to have huge capacity just in case one of the peaks come through at a particular time – a very hot day when you need a lot of cooling, and so a lot of demand.” he said.

“With storage, you don’t have to have all of that massive production of energy.”

Another Colin, my husband, seems strangely excited by the great battery breakthrough, if that’s what it turns out to be.

He says his next car will be, if not totally electric, then at least hybrid. Depending on how that goes, he says, a home battery might be next.

For homes like ours, where cutting energy consumption is an aspiration honoured more in the breach than in the reality, the home battery could be truly revolutionary.

Reproduced with permission from BeHome the blog of the Home Renaissance Foundation.  

Joanna Roughton is raising the voice for Home Renaissance Foundation as its Media Relations Manager. Jo was formerly senior editor at Reuters in Hong Kong and Singapore, and Head of Foreign News at Sky...