wiki/Gravitational_energy 
PotentialEnergy
of AirborneMass by Height (update and review)
Sept. 6,m 2014 Dave Santos 
Sept. 8,
2014 Dennis Stevens You say “A kilo raised to 100m stores 2.72Whr…” A Kilo weighs 9.8 Newtons, and when raised 100 M, has potential energy of 980 NewtonMeters. 980 NewtonMeters is the same as 980 Joules, which is the same as 980 WattSeconds. Dividing 980 WattSeconds by 3,600 Seconds per Hour yields an energy of 0.272 WattHours. Your result is too high by a factor of ten. I thought someone would catch that by now, but they didn’t. 
Sep[t. 8, 2014 Dave
Santos Dennis, We are plagued by orderofmagnitude (and greater) fingersandtoes arithmetic errors here, so your help catching them is appreciated. In this case, lets adjust the height to 1km, for simplicity, and remember ~3W, for our ruleofthumb. The corrected formula 1kg raised 1km stores 2.72Whr As most everyone stopped using hand calculators when math programs took over, we lost handiness. I am regressed in keeping a vintage slide rule handy (Aristo MultiLog), "just enough math to be dangerous", as Wayne German likes to put it (enough math for unlimited mistakes, as well), 
Sept 8, 2014 Dave Santos Whoops, "3Whr" that is (for ruleofthumb). 
Sept. 8, 2014 Dennis
Stevens DaveS writes about using the geopotential energy of a kite system as it descends during lulls in the wind. He speaks of raising one Kilo by 100 Meters, which I say (see below) establishes 0.272 WattHour of potential energy. Now…let’s see. What if we raise 1000 Metric Tons by 100 Meters. Now we have increased potential energy by 272 KWHr. I have a little Audi TT roadster that weighs about a Metric Ton. We could use a kite system to tow 1000 of them up a 100 Meter hill, and let them coast down the hill. If we convert the resultant kinetic energy into electric energy (at 100% efficiency), and if we value a KWHr at 10 cents, then we could sell the energy for $27.20. HUBBA DUBBA WINGDING! $27.20, and all we need is the big kite and 1000 roadsters. Or, maybe we could tow one roadster up the hill 1000 times. AARG! Dennis 
Sept. 8, 2014 Dave Santos Dennis, Obviously, pumpedhydro storage is already an economic massbyheight energystorage medium (constrained by a shortage of sites), so your reductoababsurdum argument is moot. Its necessary to imagine the inhuman scale of these ideas at their ultimate engineering and geophysical scales, without reference to quaint humanscale objects like roadsters. Keep in mind that energy storage often has a premium value: For example, one does not expect a UPS's stored kWhrs to be costed like electric utility kWhrs, but costed according to criticality. Allow that there will be synergistic profits in massaloft, from refrigeration (incl cryogenic energy cycling) to civilizational aerotecture. Concede how improbable your roadster would seem, from a sufficiently primitive perspective, daveS 
Setpt. 8, 2014 Joe
Faust Cents per kWhr DennisS'
10 cents seems to be a good figure for rough calculations
for the USA.

Sept.8, 2014
Dave Santos Agreed, 10 cents kWhr is the correct rounded figure for the US currently, but this topic is not about comparing a futuristic energy storage with global market prices (like 20x Antarctica prices ~2.00USD kWhr). We have no idea yet what the economics will be of future megamass aloft. Imagine how expensive an International Space Station battery kWhr must be, but the electrical engineers forged ahead anyway. A robberbaron fantasy energymarket view of AWE is not everything. I am calculating kitelevitating civilization next, with height as buffer energystorage, but by wattage and environmental impacts only, since actual costs vary greatly by willful cultural choices to spend whatever necessary to meet deep desirements (as Wubbo observed). 
Aug. 16, 2019
Joe Faust Japanese giant backs 'energy storage tower' pioneer with 110m ======================================================
Get
mass up; let mass down.
AWES
may capitalize on the capability of raising mass to high altitudes for
storage of potential energy. Let the mass down to drive electric
generators or pumps.
