Standing in front of images of smoking power plants, and graphs showing ever-climbing CO2 concentrations in the atmosphere, Elon Musk was quite direct with his choice of words. ‘I think we collectively should do something about this,’ he concluded, drawing wild cheers from his audience.
This speech took place just a few weeks ago, when Musk and Tesla – his electric car company which is busy transforming the automotive industry – launched the ‘Powerwall’, marketed as the first wall-mounted battery for the home. With a lithium-ion core, it’s an adaptation of the power source used so successfully in Tesla cars. An individual unit stores ten kilowatt hours of electric energy, enabling our homes to become self-contained and off-grid sites, fed by personal or community-owned renewable power generators, for just $3,500.
The Powerwall’s impact on renewables – which appears to drive Musk – is what has generated the largest response, with the idea that energy produced by solar, wind, or other forms could now be stored within homes until required. The problem of a guaranteed stable power supply has been repeatedly used by critics of renewable energy as a reason not to scale up operations, with fossil fuels such as coal and gas able to be burnt whenever necessary, as opposed to the intermittent nature of sunshine or strong winds.
Reinventing the battery in the form of the Powerwall could finally realise the true potential of renewable power generation, making it easier than ever before for people to disconnect from fossil fuel-producing, nation-wide energy systems. As Musk mentions, it could also (cost allowing) be extremely beneficial in parts of the world with no or intermittent power supplies, having a huge consequential impact on global development.
‘There will come a point where energy storage is going to be the vital partner to renewables,’ says campaigner and sustainability adviser Tony Juniper. ‘There are several families of technology that can help to do this. One, of course, is battery technology.’
Juniper predicts the Tesla battery will be ‘hugely disruptive’, inspiring people to keep improving that technology and improving efficiency. ‘At the same time there are people looking at other potential storage routes,’ he continues. ‘One I came across recently was using excess wind power and solar when people are not using it to be able to manufacture hydrogen, which can then be combined with carbon dioxide from flue gas and power stations to make methane, which then is used as a storage medium in the form of natural gas.’
‘We’ve had pump storage for some time; pumping water uphill when the wind is blowing. And then for heat storage, liquid salt technology that’s being used with concentrating solar power in desert areas. This is basically a super-heated molten material that enables you to generate heat. You can then generate power with that on a steam-driven turbine. So there are probably several ways in which we might be able to crack this problem.’
Of course, the environmental credentials of a battery also depend upon the initial sourcing of resources at the start of the production process. Industry experts have long experimented with the idea of recycling batteries as we do with metals, paper and other materials, but for a long time it was unclear whether it was possible to recycle and reuse post-consumer batteries into new products. Energizer is the first to show meaningful progress on this issue, with the release of its ‘EcoAdvanced’ single-use, alkaline batteries, containing four per cent recycled batteries.
While four per cent may not appear a significant proportion, the goal is to increase this number to 40 per cent by 2025. And, as it points out, all previous batteries – of which there are 500 million sold in the UK each year – have contained zero per cent recycled material, so anything more than that is worth acknowledging.
‘Recycled products that are actually better than the original will make sustainability truly mainstream,’ says Marc Boolish, Director of Technology at Energizer. He insists the core materials in the batteries are now able to be reused over and over without diminishing in any way, potentially kickstarting a system where batteries can be constantly recycled, and ending the reliance on mining of new raw materials.
There is clearly still a long way to go in order to meaningfully transform the way the battery industry operates. But the technology innovations being experimented with by different organisations shows that progress is steadily taking place. We may be seeing the start of a revolution which can solve both renewable energy storage and mineral resource depletion for good.