Seasonal Energy Storage is a fancy term relating to something humanity has been doing for a very long time – burning wood and other biomass.
As we shift away from fossil fuels more towards renewable energy; the intermittent nature of these resources means energy storage is the next holy grail. There’s been so much progress in this area; but more needs to be made before we can transition to 100% renewables.
I’ve never viewed a lump of wood as an energy storage device; but I guess it is. Wood and other forms of biomass could play an important role in a renewable energy system with wind and solar power as the centerpiece.
So how much storage would the USA need to back up wind and solar-centric power generation system? Between 7% and 26% of total electricity demand it seems.
And where would all this biomass come from? It would take a lot of land to grow the biomass and we’ve wrecked so much of that already.
That is where part of the answer may lie – abandoned croplands. I had no idea so much existed in the USA. According to a recent study, there’s around 71 million hectares of it. 71 million hectares is approximately 274,133 square miles; larger than the state of Texas.
What form would that biomass take? Rather than trees, switchgrass is one possibility. Not only can it be burned much the same way as coal, it can also be used in liquid fuel production (e.g. ethanol and butanol), and synthetic gases.
Switchgrass is already being used in some facilities in combination with coal; which reduces power plant emissions. Special burners have also been designed to burn it specifically.
I can’t say I’m really keen on burning anything to create power; it seems to me to be just the same old, same old; but I’m not familiar with new technologies or how clean they are.
I’m also not aware of how energy or resource intensive cultivating something like switchgrass would be, but it’s a US native and apparently quite hardy. There are other biofuel crops that can also be grown on marginal lands.
Personally, I’d love to see that fallow 71 million hectares returned to its natural state; but that’s a bit of a pipe dream.
Still, it’s great to see all sorts of alternatives to the black death (coal) appearing and a renewable energy future becoming more of a reality each day. Energy storage of this nature doesn’t need to be an either/or situation either – many different technologies will likely be used.
You can view the study, “Seasonal energy storage using bioenergy production from abandoned croplands” here.