Re:The Way Humans Get Electricity Is About to Change
by cfsc on Tuesday June 23, 2015 @12:45PM
(#9765836)
I will give you the example of my country, Portugal. We have very rainy winters and the reservoirs usually get full. At some points the entire production of the country is provided by hydraulic power (minus the base coal plants that can't be stopped). With rain usually comes a lot of wind. The eolic energy is sent to the Spanish grid for free, since the energy needs are meet by the hydraulic energy alone.
In summer, we have very dry weather and the reservoirs are used just for top the demand of peak hours. The wind is irregular and more prevalent at night. Now we are retrofitting some dams to allow pumping, so the excess wind power at night is used to pump water back into the dam. This process unfortunately only has 60 % efficiency.
My main point is, for the price of all those eolic towers, pumping dams and gas power plants that backup the renewables, we could build a more reliable nuclear fission power plant at a lower price.
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Re:The Way Humans Get Electricity Is About to Change
by Retric on Tuesday June 23, 2015 @01:03PM
(#9765966)
Sounds like they undersized their dams. In some places dams are designed to hold back several years’ worth of water, as in filling it from zero would take more than 1 year while the river stops flowing. This becomes impractical for the largest rivers, but larger rivers often have a network of dams to achieve the same effect.
EX: The hoover dam can hold a little over 1 year worth of Colorado River flow, but the Glen Canyon Dam is also on the Colorado river and its almost as large. (Av flow = 637m3/second ~= 2e10 m3 per year, Lake Powell holds up to 30.001 km3 or 3e10 m3. Though a fair amount of the top and bottom is reserve capacity you don't want to use.
In the end ~50% dam over capacity let's you shift most energy production to any point in the year. Granted, this is much harder to do in wet areas, but it sounds like your already producing most of your energy from renewables so it's probably a non-issue.
Re:The Way Humans Get Electricity Is About to Change
by baakss on Tuesday June 23, 2015 @01:46PM
(#9766321)
The scientific community does seem to be rethinking the environmental impact of wind energy at this point. Supposedly the drag created by windmills is enormous for the amount of energy they provide, so in order to take up a greater portion of our current energy needs, it would drastically harm the environment from essentially slowing down the wind. Local temperatures rise substantially, but there's meteorological effects beyond that that are not fully understood at this time. Here's a primer article on what's been found.
http://www.seas.harvard.edu/news/2013/02/rethinking-wind-pow...
Re:The Way Humans Get Electricity Is About to Change
by nate_meurer on Tuesday June 23, 2015 @06:04PM
(#9768154)
Do you have a citation for that? The link you provides says nothing about environmental harm from "slowing down the wind".
Re:The Way Humans Get Electricity Is About to Change
by JoeAltmaier on Tuesday June 23, 2015 @03:09PM
(#9766965)
I doubt it'd be more significant that planting trees, which is generally considered a good thing. Regardless of the wind effects. In fact slowing the wind is almost always a plus.