Questions tagged [renewable-energy]
Energy sources that do not rely on the consumption of an exhaustible fuel. Tidal, geothermal, and the direct and indirect solar energies (direct: photovoltaics, CSP, solar thermal; indirect: wind, wave, biomass) are renewable energy.
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"Single-shot" Heat engine efficiency limits
The sun is 5778K and Earth is ~290K. Using the sun as the hot reservoir and earth as a cold reservoir we get 95% Carnot efficiency. However, the solar power efficiency limit is only 86%, see: http://...
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Why are spin coated polymer solar cells more efficient?
Reading papers on polymer solar cells (PSC from now on), it is seen that many different coating techniques are used in order to coat polymer films on substrates. It is also seen that spin coated ...
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Unusual temperature shape in gravel heat storage
I’m currently doing undergrad research on using a gravel (basalt 2-5mm grain size) bed as an heat storage. In order to heat up the gravel inside, hot (~100°C) and dry (RF<4%) air with a pressure of ...
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Why is the Weibull distribution used to describe wind speeds?
Frequently, it is stated that the distribution of wind speed at a certain location can be described by the so-called Weibull distribution:
$$
W(x;\lambda,k):=\frac{k}{\lambda}\left(\frac{x}{\lambda}\...
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What is and how do you calculate design wind speed, on wind turbines?
I am finding hard to get a consense on the definition of design wind speed, on eolic turbine matter.
I thought it was he velocity that correspondes to the maximum power output, but I have already ...
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Power grid stability in an only inverter grid
I think i there is little misconception in my head regarding the cause and effect of changing grid frequency and therefore I am confused about the transition from fossil fuels to regeneragtive energy ...
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How big is the power loss of a downwind wind turbine due to turbulence created by an upwind turbine?
When a horizontal axis wind turbine is placed downwind of another horizontal axis wind turbine (distance between the two is minimal), then the downwind wind turbine has a lower power output because of
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Measurements of the pressure drop across wind turbines?
Mathematical analyses of wind turbines show that a discontinuous pressure drop happens at the rotor plane. I am looking for measurements of this effect, but I could not find any. Do you know any (...
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Is it possible to boost solar panel output using wavelength shifting materials?
Solar panels only produce energy from a small section of the total wavelength spectrum of light. I believe some panels have a mirrored back to pass light through the solar panel a second time. Much of ...
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Can you use the water flow exiting a hydroelectric generator to generate more energy?
In videos of hydroelectric generators I often see that the water that exits a turbine is still moving with significant velocity.
Example of a turbine that has exit water flow with significant velocity:...
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Wind turbines or tidal power stations incorporating elements of origami or reconfigurable materials: is innovation possible from physics?
If I refer well (I'm not a physicist) one of the oldest uses/applications of renewable energy is to try to exploit the wind and tides by means of designs of machines: windmills and water wheels. Today ...
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Can a positive ion generator ionizing water create electricity with a net gain of electricity?
Traditional ion generators work by sending electricity through air to ionize air with a negative charge. This is said to benefit human health. But, it should be possible to extract ions from atoms and ...
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Textbook recommendation renewable energy
I am supposed to teach a lecture on the broad field of renewable energy for the first time. I wanted to check how other people cover the field, but there is a plethora of books on the subject and even ...
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On what planet within the Asteroid Belt would solar panels work the best?
I was researching for a project and came across this question. Maybe this is a bit too broad? How might solar energy work on Mars? Would it be sufficient to sustain a colony?
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Is there common ground between wind and solar technologies/methods for harnessing energy? And how does this compare to nonrenewable methods?
To clarify: not asking similarities between solar and wind energy as a whole but only its technologies/methods of harnessing energy [example: ?turbine blades? in solar towers and wind turbines]
Is ...
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