Comments on: Alternatives

By: john hare

john hare — Wed, 27 Jan 2010 10:43:47 +0000

For the large surface area per volume in the lower cavern, a lateral drilling rig might be useful if it would operate underwater as well. One rig could continously expand storage capabilities. I think you are right on needing the geothermal assist, unless you have a location with no other available storage means that are economical.

By: PeterH

PeterH — Wed, 27 Jan 2010 05:19:58 +0000

This could be a winner with geothermal sources hot enough to boil water, but not hot enough to produce much steam pressure. To maximize this you’d want the lower cave to have large area as opposed to volume. As for salt deposits, pull some of the water out in liquid form with the salt. Without geothermal assist pulling out the water as vapor would be a killer loss, I expect even for energy storage.

By: A_M_Swallow

A_M_Swallow — Tue, 17 Nov 2009 15:11:11 +0000

A natural gas field is not somewhere I would want to pump oxygen. The combination is likely to catch fire or explode.

By: john hare

john hare — Tue, 17 Nov 2009 10:30:07 +0000

Any place that has natural features that support energy storage will use them. It seems probable that Japan doesn’t have too many natural reservours available.

By: Nels Anderson

Nels Anderson — Tue, 17 Nov 2009 06:21:07 +0000

An article by Zweibel et al. in the Dec. 2007 Scientific American discusses the use of depleted natural-gas fields to store energy. During the day, excess solar-generated electricity is used to pump compressed air into the fields. At night, the air is released through turbines. Because it uses natural reservoirs, this scheme might be much cheaper than one requiring the construction of underground water storage spaces.

By: john hare

john hare — Tue, 10 Nov 2009 10:27:54 +0000

This is an energy storage proposal for Earth based solar, wind, and other intermitent power sources. Due to efficiency losses, it will take more power to get the vapor out of the hole than you get from the water going in. The geothermal assist will help in some locations, won’t apply in some, and might be the primary power source in others.

The salt is a resource, along with other minerals evaporated out.

By: jsuros

jsuros — Tue, 10 Nov 2009 02:35:27 +0000

I’m afraid the kinetic energy needed to get the vapor out of the hole will rob you of most of the energy you think you’d get out of the pressure head down your hole. You’d also fill up your underground chamber with evaporated salt in short order.

If you drilled down from the sea and up to somewhere on land that was below sea level, it might work. The coast of California to death valley, for instance. Or from the Mediterranean sea to the lowlands of the Sahara dessert.

This idea really seems to work better when viewed as a way of hydrating desert lowlands rather than a power generation scheme.

By: Pete

Pete — Mon, 09 Nov 2009 17:44:27 +0000

I am still waiting for extremely low cost solar power to be demonstrated in space for the powering of satellites, space stations and what not. I am not sure what the current cost of electricity produced in space is, but I would expect it to still be on the order of at least tens times that on Earth.

Once low cost electricity in space is demonstrated, then we will have all the more reason to go there and use it – at the source where it is cheapest. An obvious first use would be much higher power satellites.