Reading the technical details on this system, I'm not very impressed
Quote:While it may sound absurd, in only a few years, Nevada's electrical grid may be stabilized by a fleet of automated trains weighing 300 tons each. The company has specifically designed the system to work best on a grade of 7.2%. This allows the best transfer of energy from potential to kinetic while also allowing the trains to maintain stability. When each 300-ton train moves down the slope, it can provide 50MW of power to help stabilize the grid. In total, the track for the Nevada system will stretch 9.2 kilometers through the desert with an elevation differential of 640 meters (2100 feet).
While the system may be useful in some circumstances, it relies on being built in a mountainous region and seems to cover a large footprint of land for a small amount of energy storage. I didn't see any costs in the article either, so I don't know how economical this energy storage system is compared to others.
Gordon wrote on Aug 21
st, 2017 at 9:07am:
miketrees wrote on Aug 21
st, 2017 at 8:58am:
I still think compressed air would be more simple
I guess it comes to the maintenance of high pressure tanks?
Could be more suitable in dry environments.
The concrete train is claiming 80% efficiency!!!
Flywheels have the same level of efficiency and have a smaller footprint. I don't know why there seems to be little interest in flywheel systems, given that their current cost per Wh is cheaper than lithium batteries and a single unit can last for up to 30 years.
A flywheel keeps losing energy. A train on top of a hill will just stay there, not losing any, waiting until the energy is needed.
Dams tend to have large footprint as well, over prime agricultural land rather than steep mountain side. But still a lot cheaper than the train idea I would expect. And flywheels would be the most expensive of the three.
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