How battery technology will determine the real future of green energy
Unless you’ve been living on a remote Pacific island for the last decade or so (in which case, can I please join you?) the name Elon Musk will be overly-familiar. He’s the gentleman who’s got one supreme talent: the ability to extract billions of dollars from over-excited venture capitalists and others who play with institutional money.
Musk claims he wants to “save the planet” or at least delay its collapse until such time as his billionaire’s panic room on Mars is ready for occupation. Presumably it takes quite a long time to ship all the caviar and champagne necessary to enjoy life on our distant arid and lifeless planetary neighbor. Staving off environmental collapse therefore, in Musk’s teen techno dream, involves everyone driving around in electric cars. Supposedly this will reduce pollution and the overall environmental impact of personal mobility.
Unfortunately, a Tesla is in fact more harmful for the environment than a regular automobile. Unless all the electricity used to charge its batteries comes from renewable sources, all a Tesla does is require more coal and gas and oil to be burned in power stations.
Musk therefore claims that his investment in Lithium-ion battery technology will help move us from fossil fuels to renewables (wind turbines and solar panels) by providing the missing piece in the whole renewables story: the ability to provide power when the wind isn’t blowing and the sun isn’t shining.
Alas, this is also not what it appears to be.
Mining Lithium is enormously damaging to the environment, as is shipping it around the world to be used in batteries. Those batteries last at best five years and can’t be recycled. This means they end up in landfill, and they’re highly toxic, so this further increases the environmental harm they inflict. Add to this is the fact that Lithium-ion batteries need Cobalt, and most of the world’s Cobalt comes from the Congo where it’s mined by impoverished adults and small children in essentially slave conditions, and you can see that a Lithium-ion battery powered Tesla isn’t really the solution to anything at all except Musk’s desire to remain for as long as possible in the public eye.
But what about the idea of moving away from fossil fuels to generate electricity? What about all those wind turbines and solar panels?
These technologies are indeed improving and do provide at least some alternative to fossil fuels. Unfortunately, the wind doesn’t always blow and the sun goes away at night. Storing electricity for use when renewables are dormant is an essential component of our move away from CO2-producing fuels. Musk would have us believe that Lithium-ion batteries are the solution to this storage problem but he’s mistaken.
Today, renewables are often used to pump water up a gradient where it is stored in a reservoir. When the renewable sources cease to provide power, the water is permitted to run back down the gradient, powering turbines as it does so. These turbines then generate electricity, thus making intermittent renewables a viable option. Water acts as the storage medium and can be retained for as long as necessary without degrading whereas Lithium-ion batteries aren’t actually very good at holding charge for extended periods of time.
Unfortunately, the losses involved in pumping water uphill are huge and the energy recovered is modest. Furthermore, not all places have convenient hills or mountains up which water can be pumped.
Fortunately, there are people who’ve been working on the storage problem for some time. Ding Yulong at the University of Birmingham in the United Kingdom has been working on a storage solution that could potentially remove the need for toxic metals entirely. His ideas have been put into practice by a British firm over the last few years and the results have been very promising.
Here’s how the new storage technology works: ordinary air is liquified by chilling it to 77 K. At this icy temperature the liquid air occupies a mere 0.14% of the volume that it occupies at room temperature. When the liquid air is allowed to expand, it can drive a turbine. And by capturing much of the heat generated during the initial compression process (perhaps in a salt or oil mixture) it’s estimated the overall storage-release efficiency can reach nearly 70% which is on par with the very best battery technologies today. Furthermore, liquified air can be stored for months or even years if required.
Liquid air technology could be scaled up to provide massive amounts of electrical storage sufficient to make renewable energy a reality within the next twenty years, without requiring the use of toxic metals. Unfortunately, so far at least, liquid air storage isn’t suitable for small-scale applications such as powering vehicles. But it would at least make electric vehicles slightly less environmentally harmful than they are today.
Which, although it’s not part of Musk’s fantastical money-burning vision, is surely a very good thing indeed.