Gravity Battery

In yesterday’s post I mentioned two Israeli companies that allegedly made big breakthroughs with solar power. Many of you noted that solar power is limited if you can’t store the energy in a cost-effective way for night use.

I did some Googling to see what’s new in battery storage, and this potential breakthrough popped up. Obviously it must be viewed skeptically until proven viable.

http://news-service.stanford.edu/news/2008/january9/nanowire-010908.html

But I got to thinking that there must be a more natural way to store energy, using gravity. It might not surprise you to learn that I found exactly this sort of idea, appropriately, in the halfbakery.com web site:

http://www.halfbakery.com/idea/energy_20storage_20gravity

http://www.halfbakery.com/idea/Windmill_20Compressor_20Home_20Energy_20System#1121567081

I know, I know, you will point out that even if such systems of energy storage existed, they would be inefficient. It takes more energy to move a rock up a hill than you can capture from the return.

But how inefficient can your storage device be and still be viable? There is some theoretical amount of cheap energy production that compensates for almost any degree of inefficient storage. So if, for example, solar panels became 1,000 times more efficient and cost you next to nothing, it might not matter if your storage device could only capture half of what you generated. You’d still have plenty to get you through the night and charge your electric car too. I think it’s entirely plausible that we’ll have home battery systems, whether gravity based or not, that make oil obsolete except for specialty situations such as jets and maybe big trucks.

Some of you noted that oil has so much energy for its weight that solar power can never be expected to replace it for cars. But that too is more of a function of battery storage. Perhaps the nanowire battery or something like it will solve that. I think it will happen. And I think Israeli companies will be in the forefront, for national defense reasons, while the United States argues about flag lapel pins.

Comments

[fatcatfan]

It's standard engineering practice to pump water into reservoirs as "battery" storage of hydroelectric power. That's basically using gravity. It's as efficient as your pumps and turbines, which have the benefit of many years of refinement. However, I wonder if there isn't some sort of capillary action system which could be used to "pump" water to a reservoir without inputting energy from the grid?

Still, that's bound to be far less efficient than storing electricity directly from a solar cell to a nanowire battery.

[Popster]

I found a link to the reversible dam I mentioned in my previous post.

http://www.asme.org/Communities/History/Landmarks/Hiwassee_Dam_Unit_2.cfm

Doing the gravity idea in an individual backyard does not seem practical. Now a neighborhood power storage system...

[Real Live Girl]

And hopefully, Mr. Burn's isn't planning on buying the sun or blocking it. LOL.

[jerry w.]

What if we could use solar power to move a rock up a hill, and then drop said rock

on the head of anyone that refused to give up driving their hummer?

Note, not on the head of anyone getting a hummer.

Nor, on anyone that's giving a hummer.

http://boskolives.wordpress.com/

[Popster]

This has been done, kinda. There is (at least there was) a dam somewhere that generates hydro power during the day. At night when energy is cheaper, the generators become motors and the turbines become pumps, lifting water back into the reservoir to reuse the next day.