"Pump Storage" using concrete and motors

[stevehull]

Don't know if any of you have heard about this. Basically, it is a reversible motor on a small rail road track that is "powered" up a hill and then generates power when it goes down the hill - at about 80+% efficiency.

The advantage of this technology is that it uses concrete (twice as dense as water) and easily hacked DC motors. Scrap steel would be even more dense.

I heard about this a few years ago, but could not find anything on it, but today saw a video.

For those on hills - just think of the possibilities!

Imagine a mass of 2200 lbs (1000 kg). Imagine a hill 100 feet high (33 meters). If I recall, the formula for power = m x 9.8 N/kg x meters. If my quick math is right, this is 323400 N-m/sec or about 323 kW of power (1000 N-m/sec = 1 kW). Allow this to move down the hill over 10 hours and you have about 32 kW per hour. This would be at 100% conversion. Even at 50% efficiency, this would run my heat pump all night.

You don't need a large elevation change when moving tons of mass up a small hill. A 10-20 kW generator is easy to imagine. If you don't have a huge hill, then add in more mass (concrete or better scrap iron or steel).

This unit can be powered by excess PV production during the day and then it would provide power at night.

FAR better than any battery!

Years ago, I worked on a water pump storage peaking system on the Connecticut River in Massachusetts. The Vermont Yankee nuke plant was just up the road and, at night, excess kW (actually mW) were used to pump water from the river up a hill into a detention pond. Then at times of peak electricity need, the water flowed downhill and through a turbine. The net efficiency was on the order of 25-33% - or about 67-75% of the energy was wasted. But it did provide excess capacity at peak use times for the Boston area at 4-8 pm.

Enjoy!

The train goes up, the train goes down: a simple new way to store energy - Vox


Steve