Lithium-ion batteries tend to overheat. When these batteries overheat, they spontaneously combust causing fires that cannot be put out. Yet, large solar farms have large battery storage stations containing hundreds of large container-sized lithium-ion batteries close to each other.
What have governments and solar farms done to mitigate or deal with this catastrophic disaster in waiting? If the US solar farms are anything to go by – nothing.
“The growing threat of grid-scale battery fires is a very serious issue calling for equally serious action,” Dr. David Wojick writes.
Grid-scale battery fires loom large
America faces a growing threat from grid-scale lithium battery fires. Construction of huge battery arrays with no concern for potentially catastrophic fires is out of control. There are no established standards to follow and local permitting authorities seem oblivious to this very real danger.
What follows is a brief introduction to the issue. To begin with look at this photo of an existing grid battery array called Desert Sunlight:
The batteries are teamed with a big solar facility because until recently that was the only way to get battery subsidies. Each lithium battery unit is the size of a tractor trailer or big shipping container and there are well over a hundred of them, with a rated storage capacity of 230 MW. This is a medium-sized storage facility.
That these units can spontaneously burst into flames is well established. The question is how to design and prepare for this destructive event.
To scale the problem, consider the following event. A battery-powered tractor-trailer rig recently crashed and its battery burned on an interstate in California. Lithium battery fires cannot be put out so this one burned for around eleven hours. To keep the fire from spreading to create a wildfire the fire crew continuously sprayed it using a reported 50,000 gallons of water in the process. The interstate was closed due to the toxic fumes from the fire.
One of these grid-scale battery units is easily 10 to 20 times the size of that truck battery. If the water usage required to keep a grid battery fire from spreading scales with size that is 500,000 to a million gallons of water. The actual amount is an engineering calculation that needs to be established and incorporated into battery facility design standards.
Note that we are not talking about the fire spreading to create a wildfire although that is certainly a concern. The vital need is to keep it from igniting the nearby batteries. If this happened the whole facility could go up with a hundred or more giant batteries burning. That would be truly catastrophic.
So now look at the Desert Sunlight photo and note there is no water tank. There should be something like a million-gallon water tank with a high-volume system to deliver that water to every unit in the facility. Clearly, there is not.
There is also the engineering question of how far apart these units should be to enable that water to work keeping the fire from spreading. I doubt the Desert Sunlight spacing is even close to big enough. It looks like just room to walk between them.
Now let’s turn to permitting these facilities where I have another example that speaks volumes. This is a facility that just got permitted by Washington State. It is a combined wind, solar and battery project with a proposed storage capacity of 300 MW, which is considerably bigger than Desert Sunlight. It might have 200 huge lithium battery units. That number is not disclosed.
The project is named the Horse Heaven Wind Farm despite its massive solar and battery components. The name, usually shortened to Horse Heaven, is truly ironic because it will be no place for horses. Horse Hell might be better.
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