What I'm wondering about is a storage facility that is incorporated in the windmill itself. We live in a very flat area and every village has a water tower. This fits on a lot not much larger than a typical house site. Ground water is pumped up (about 100 feet or 30 meters) and then gravity is used to provide the water pressure to the homes. Just imagine if each water tower had a windmill on top, or rather that each windmill was on top of a water tank. The water doesn't need to be part of any municipal system it could just shuttle between an underground and raised tank. How large would the tank need to be (or how high) to store a reasonable amount of power and how would this affect the economics of the project? Policies not Politics ---- Daily Landscape
from wikipedia http://en.wikipedia.org/wiki/Pumped_storage_hydroelectricity
The relatively low energy density of pumped storage systems requires either a very large body of water or a large variation in height. For example, 1000 kilograms of water (1 cubic meter) at the top of a 100 meter tower has a potential energy of about 0.272 kW·h. The only way to store a significant amount of energy is by having a large body of water located on a hill relatively near, but as high as possible above, a second body of water
if 1m3 at 100 meter only gets you 0.25 kWhr, that's going to be one big ass tank
In terms of hydro power, that translates into greater volumes of water, or of greater head, heighth of the column of water. I have seen numbers relating acre feet of water vs head heighth to MWH of energy stored. The numbers are huge, generally in terms of volume since available head heighth is usually limited to at most a few hundred feet and dictated by the site. As best I remember, the volumes of water required to produce a MWH of energy are in the millions of tons. Granted, the numbers I'm thinking of relate to large hydro projects, but still, the numbers are very large.
I'm thinking storage on the scale of single wind turbines would still involve either relatively great heights or relatively large volumes of water. If there is any merit to my speculation, a big if, then I would wonder about the relative economics of individual turbine scale storage vs larger scale storage. Again, I don't know any of that for a fact, just guessing. I would be glad to hear from anyone who has better information. Now where are we going and what's with the handbasket?
why mess with water when any weight will do, and some are so much denser?
anyone remeber those cuckoo clcks where you pulle a chain to raise a weight, and then it slowly ran down, powering the clock?
having said that, i do think that many of our best initiatives will be to encourage swamps, estuaries, marshlands, bayous and fens, because per acre these support the most fauna, much of it edible.
i aslso believe we will make water a much bigger feature of planned landscapes, for its aesthetic and therapeutic value, as much as for storage.
so much rainwater rubs off uncaught, leading to such absurd scenarios as rainy england suffering intense water shortage.
for terraforming, grey water purification, and aquaculture/greenhouse combos, expect to see much heightened consciousness of water, its preciousnessness and its balancing qualities on many levels.
aquarius - the water-bearer...
can we imagine if a tiny portion of the 8 billion$ a month poured into the black hole of baghdad were redirected into battery research?
instead of 'assault-and-battery'? ~Government budget deficits are not nearly as dangerous as the deficits we have created in vital and complex natural systems.~ Naomi Klein.
People are exploring spinning flywheels and battery systems though.
Indeed. Talk about opportunity cost... Now where are we going and what's with the handbasket?
Ignoring moderate inefficiencies, storing energy by lifting stuff requires 100 kg-m per kilowatt-second. Choosing a numerically convenient tower height of 36 m, the amount of water required is 10 tonnes per kW-hr.
Choosing some round numbers, a small town might consume 10 MW; at this power delivery rate, a 10 hr energy-storage buffer would require a million tonnes lifted 36 meters. A million tons is about 10 times the mass of this nuclear-powered, Nimitz-class aircraft carrier:
BTW, the U.S. is now fitting out the USS George H. W. Bush, the tenth of this class. Words and ideas I offer here may be used freely and without attribution.
