alt.energy.renewable

"Erdeemal" wrote in message
news:47f5fbae$0$666$4d4efb8e@read.news.be.uu.net...
> Jeff Dad wrote:
>> Here is my idea:
>>
>> If a 3-10 M deep pit were dug and a several thousand Kilo weight were
>> attached to cables and a generator and slowly, via mechanicle gear
>> system, raised with excess Wind energy, solar energy, human effort,
>> and less expensive evening electricity from existing grid, could this
>> device could be used to spin up a flywheel generator as it dropped and
>> provide cleaner, cheaper power to a house?
>>
>> If this makes high-level sense, I need some technical engineering help
>> in designing a prototype. Anyone interested?
>>
>> First off, how much weight, how high, and how big a generator would we
>> need to be of use?
>> I'm assuming a pit is the way to go to make it safer.
>>
>> What materials are needed to make it strong, and last a long time
>> (20-50 years)?
>>
>> What mechanism would be most efficient in raising the weight and in
>> transferring small amounts of energy into lift?
>
>
> Pretty easy to compute :)
>
> W = F * L
>
> ??3-10M?? = lets assume you dig 10 meter deep, 10 miles
> sounds too much
>
> 1000 kg falling 10 meter will poroduce an energy of
> 1000 * 10 * 10 = 100.000 Joule
> or 100.000/3,600,000 = 0.0278 kWh :)
>
> To store one single kWh it will require 36000 kg falling
> 10 meter (~80000 lb falling 33 feet)
>
> Let's suppose each kwH this will spare you $0.20 ...
>
> In the ocean, you can go 3 miles with no digging ...
> ever think about that Albert ?

All-in-all, it would make more sense to pump water to a higher location and use
it to generate power when needed. The losses would be higher, but the cost would
be far lower.