Comment by nixon_why69
7 hours ago
If you're going mechanical, why not pumped water storage instead? Nothing has to spin super fast and hydro has a lot of maturity.
(From a guy who got burned buying stock in a centrifugal system as my first "wicked smaht" investment as a 22yo).
there are areas where almost all options for pumped hydro are already developed and there's little room for expansion. additionally, the heat waves from the climate catastrophe affects pumped hydro negatively (evaporation and higher water temperature).
Evaporation can be solved by covering the reservoirs, so the water can't evaporate. Geography is the real issue. Costs to build possibly too.
Mostly because we already used all suitable places. It also has a huge environmental impact, large upfront costs that you can only spend in bulk, permissions, lawsuits, protests from the local population and so forth.
Hydro is limited by geography. It cannot scale in the same way. Rather than giant spinning masses at central locations, current thinking is more about smaller masses scattered throughout a grid. There are even a few studies on whether existing air conditioner/heat pump compressors could contribute.
I think geographic dispersion of batteries is going to be a big plus. If the "battery" is a giant lake or a big plant with a spinning mass, the power has to be transmitted from that facility to the end user over the grid
Putting a ton of smaller chemical batteries at distribution substations means when the grid is at the peak, you can cover that peak without transmitting that power over the transmission system. Putting the battery near the consumer will take a big load off of the transmission system which as much of a bottleneck as the lack of generating facilities