Just got this forwarded letter from my Investment broker-------
Good morning,
Although it’s not yet been proven at commercial scale, a company called Advanced Rail Energy Storage is attempting to build a grid-scale energy storage solution similar to pumped hydro storage.
ARES' system involves building a small electric railroad that draws excess electricity from a solar- or wind-powered plant, and uses it to drive trains loaded with heavy rocks or weights up a grade. Then, when that energy is needed later, the cars will roll back down the slope. On the way down, the trains' motors use regenerative braking — the same technology that powers streetcars and cars like the Toyota Prius — to generate electricity, which goes into the grid.
Although the technology currently pales in comparison to the storage capacity of pumped storage installations, the advantage is that ARES only needs a sufficient slope to run their track, broadening the range of locations the facilities could be built in. Particularly in the context of solar energy storage, where generation plants can often be located in regions devoid of natural water sources, this could make a lot of sense. Additionally, rail-based energy storage would have a much lesser impact on the environment than most existing pumped storage facilities, which require two bodies of water (often man-made) at different elevations to be connected by a tunnel (often bored).
ARES claims its "fast response technology bridges the power gap between smaller battery and flywheel installations and far larger pumped storage hydro -- at a lower life-cycle cost than batteries, a higher energy-to-power ratio than flywheels, and a greater efficiency and far faster ramp-rate than pumped storage."
The next step for ARES is to move from the prototype stage to construction of a full-scale test facility in Nevada. The first-of-a-kind project is expected to cost $55 million. At the moment, ARES’s plan is simply to draw power from the grid when it is cheap and sell it back when it is expensive. But the logical end of the line for such a railway is as a load-balancer for local solar-power stations.
and.....
lots of innovation out there!