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Condensation Pontoons

Preserve water for hydropower
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Considera high resevoir for pumped-storage hydropower and conventional hydropower.

Water evaporates, reducing the amount of energy available from hydro.

However, if a series of pontoons were contructed, with a solar powered condesation, some of the evaporated water would drip back into the resevoir. And, there would be shade to prevent evaporation as well. Waste heat would be expelled as dry air up a chimney.

All surfaces, especially the cold surfaces, need to be "safe". i.e. no chance of dissolved heavy metals, etc.

They would be designed with bumpers so that several could be released on a resevoir surface, and just bump into each other throughout the day.

Not the best use of solar power, but they wouldn't need to be attached to the grid directly.

Madai, Apr 15 2013

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       <sp>   

       "Condensation."   

       Or was that supposed to be "Condescending?"
whlanteigne, Apr 15 2013
  

       If the idea is to prevent loss of water (and thus of potential hydroelectric generating power), how big are such losses at present? I find it hard to imagine a usefully large mass of water losing much by evaporation in the time between its being raised and being used for generation.   

       Am I wrong? Numbers?
MaxwellBuchanan, Apr 15 2013
  

       I'm going to go out on a limb here and suggest it would take more power for the "condesation" process than would be gained.
whlanteigne, Apr 15 2013
  

       For swimming pools, 1-2cm is typically lost per day by evaporation (according to the first web page I found). I'm guessing a hydroelectric storage tank will be at least a couple of metres deep, meaning that evaporative losses will be on the order of a percent or less.
MaxwellBuchanan, Apr 15 2013
  

       Again, out on a limb here, but I'm guessing it would be more efficient and effective to simply plug the solar panels into the grid.
whlanteigne, Apr 15 2013
  

       The cost of hydropower on a per-gallon basis is negligible.   

       HOWEVER, water doesn't just generate power. After it goes through the dam, it goes to residential use.   

       In the western US, costs for water are rising steadily. It's a moving target, to be sure, but in the worst case you have Santa Fe, $21 for 1000 gallons after you've used up the $6/1000 gal "discount" water each month.   

       I estimate a $300 dollar system (solar plate, cooling elements, floats, mass-produced) can condense 2 gallons a day with current tech. That means that if water prices HOLD and don't rise, we are looking at a 20-year payback, vs the 10year payback for grid solar. But over time, I expect:   

       1. water prices to rise, especially in the western US. -and- 2. Solar prices to fall, -and- 3. More solar power than the grid can even use.   

       So, the trick will be finding ways to put solar power to work in remote places where a grid isn't needed.
Madai, Apr 17 2013
  

       Wouldn't it be more effective to run your condensers on hydroelectric power, and make their upper surfaces white? Photovoltaics are relatively expensive, and become relatively hot.
spidermother, Apr 18 2013
  

       Spidermother, the photvoltaics would be well above the surface of the water and the condensers. All the heat would stay well away from the water.
Madai, Apr 18 2013
  

       Generally, and particularly in a deep reservoir, the water stratifies with the deep water being quite cold.   

       So, to chill the condensation side of your condenser, just drop a tube down some distance, use your solar electricity to pump water up and through some pipework, then release the water back down into the reservoir.   

       It'll only take a minuscule amount of power to move the water (it doesn't have to move fast) and you don't have to cool it.   

       Make the pontoon-and-roof structure big enough to house a small deck - for fishing & picnicking. Rent them out - along with small boats (electric powered, with trolling motors). If the weather's sunny, your customers will want the floating dock to charge the boat; if it's rainy, they'll get a sheltered place to fish from.
lurch, Apr 18 2013
  

       [Madai] You need to dump the heat somewhere. It seems to me that the area occupied by solar panels might be better occupied by a cooler heat sink, to reduce the work required of the heat pump.   

       Photovoltaics would eliminate external wiring, but when you've got the worlds cheapest source of power right there, you might as well use it.
spidermother, Apr 18 2013
  

       you dump the heat into dry air, which you vent upward. done right it might all be passive:   

       ambient air flows under the pontoon near the coooling element. Once cooled and dried, it is sucked into the heat sink system. once it passes through the heat sinks it rises up a small chimney.   

       If you start with 70 degree air with a dewpoint of 50, and cool it to 30 degrees, it will lose water to condensation and the dew point of the cooled air will now be 30. from there the air temperature rises, but the dew point stays the same.
Madai, Apr 22 2013
  
      
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