The renewable energy industry and the government, too, are deceiving the public and their investors about grid scale energy storage with lithium ion batteries. Not only are the battery "farms" too small for the task – only able to bridge the intermittent supply of renewables for 2 to 3 hours – but the danger that they present to the public and fire fighters is ignored and unregulated. This contrasts with the danger from nuclear power which is fabricated and publicised, endlessly.
The situation is explained in a recent paper that is getting worldwide attention (in the week to July 18 the most read paper posted by Oxford University). At a popular level the Mail on Sunday reported it on July 11.
Stored energy can bridge the gap when energy is needed but is not available. Such stores have become essential in modern life. Initially it was just the dry battery in a torch or radio and the lead acid battery in a car providing lighting and a means of starting. The capacity of such a 12 volt battery might be 100 Ampere hours – that is 1.2 kilo-watt hours (kWh). But the scale has increased by a factor of 100,000 and more. For example, the capacity of the Hornsdale Power Reserve in S. Australia, famously provided by Tesla, is now 193 MWh.
The demand for increased storage comes from the intermittency of wind and solar. These threaten breaks in supply lasting for days, even weeks. With national electricity consumption figures in tens of giga-watts and more expected with increased electrification, stores with a capacity thousands of times larger than Hornsdale are needed. Those currently under construction or planned could provide back-up for 3 to 4 hours which is simply inadequate. The likelihood of supply failure and extended blackouts, as recently experienced in Texas and California, underline the importance of this question.
The availability of the minerals to make batteries even on the present scale has excited the markets. However, large batteries may not be feasible or even desirable in the decades to come.
Climate Change is already here, and weather conditions are likely to deteriorate further for many decades yet, whether we reach NetZero by 2050 or not. So acceptable energy sources should be resilient, reliable and safe.
Batteries are chemical and store energy by separating components. This energy may then be released again when the components recombine. It is dangerous if control of this recombination is lost. In some batteries, like flow batteries or fuel cells, the components can be kept well apart, ensuring safety. However, in the popular Lithium-Ion battery they may not be. If recombination starts to take place inside the battery cell, the released energy raises the temperature, likely precipitating further failure. Such a "battery fire" is demonstrated in this video. The internal energy released needs no air to "burn" and is not extinguishable in the normal way. Indeed, like the chemical fertiliser bomb that destroyed much of Beirut in 2020, batteries may simply explode. Some grid storage batteries now being built are, indeed, as powerful as the Beirut bomb.
But is there evidence that such fires and explosions happen frequently in practice? On April 16th 2021 a 25 MWh energy store in central Beijing that also provided rapid charging facilities for electric cars suffered a major battery fire. The report of the International Association of Fire and Rescue Services tells how the fire was attended by 47 fire trucks from 15 brigades and 235 fire fighters of whom 2 were killed. The reason for this large response and international interest is that such incidents have become rather frequent. More recently in July 2021, 5000 residents of Chicago were evacuated when 200,000 lithium batteries stored in a warehouse started exploding. The fire brigade did not use water, wisely, and attempted to contain the blaze with 28 tons of Portland cement. A lithium battery fire releases, not only a large amount of energy, but also large quantities of toxic gases including hydrogen fluoride, which is exceptionally corrosive. If water is used, it is not effective at extinguishing the fire and generates highly polluted run off. Instead of cement the fire service might have used sand, but there was little else they could do.
An earlier incident in April 2019 in Arizona critically injured 4 firefighters and 32 such fires and explosions in South Korea were investigated. But this experience did not prevent an explosion of a 20 MWh lithium ion energy store in Liverpool in Sept 2020 – a long-promised report is still awaited.
Following a recent academic study, questions have been asked in the UK Parliament. Unfortunately, BEIS, the department with responsibility for energy, seems to be exclusively concerned with reaching NetZero and so with an uninterrupted programme of electrification and roll-out of wind and solar. Meanwhile, the Health and Safety Executive that comes under a separate department applies no special regulations to the safety of large lithium ion battery stores or their planning! It is then left to small groups of concerned citizens (for example in Northern Ireland) to try to impress the dangers on the authorities and warn them before another avoidable disaster like Grenfell Tower occurs. So far, the instances of explosion and fire have been relatively small, 25 MWh or less. The next one could well be much larger.
Fashionable financial investments in wind and solar (and in lithium ion batteries on which their viability hangs) are blind to this question. They have allowed themselves to be boxed into a corner where these renewables are presented as the only carbon-free option – and the best hope for dying fossil fuel industries.
The only energy source that will be sufficient and safe in future is nuclear power. As for lithium batteries the safety case relies on evidence, not political wishes. Popular opinion, still in the thrall of scary cold war stories, has not noticed, apparently, that there were no nuclear casualties at Fukushima Daiichi, remarkably few at Chernobyl, and none in nuclear plants elsewhere. Unreliable renewable energy combined with the danger of large batteries should not be inflicted on society when a safe route to zero carbon is at hand.
Note: The first paragraph was added on July 22, 2021 at 9:35 and the title changed from "Are big batteries a safe and sensible investment?" to "The danger and inadequacy of lithium storage batteries".