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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Growth of Current in an Inductor Connected Across a Battery [duplicate]
When baterry is connected across inductor with no resistance in circuit, won't the current flowing through it be zero, as inductor back emf will counteract the effect of potential difference due to ...
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Is cold fusion the only avenue for fusion reactors? [closed]
To my understanding, cold fusion proposes a solution to usable fusion reactions by finding a way to fuse nuclei at room or near-room temperatures. However, I also understand that improving energy in ...
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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 ...
CommunityBot
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Total flux is bigger than radiation flux, error?
The topic of this question is the collection of radiation from the sun. (renewable energy course) The total radiation flux is $$I_\text{total} = I_\text{direct}+I_\text{diffracted}+I_\text{reflected} ....
rob♦
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How could more rotor speed mean less energy in wind turbine?
there's a question that has been annoying me for a while, consider the following (power,rotor speed) diagram for different wind speeds
at some wind speed (6m/s for example) how could a turbine ...
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If water vapour is a green house gas , then how is using hydrogen fuel cell stopping global warming?
Hydrogen fuel cells produce water vapour then aren't they also contributing towards global warming ?
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Why is there no upper-bound on power-efficiency of Hydro-turbines?
We have Betz's law, an upper bound on power efficiency, for wind-turbines. But there is no theoretical upper limit on hydro-turbines, Why this is so?
Is it mainly due to the incompressibility of ...
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Is plant photosynthesis more efficient than solar panels?
Is photosynthesis more efficient than solar panels? If so, by how much?
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Does the second law of thermodynamics imply that renewable energy also leads to global warming/climate change?
So I have this (possibly dumb) question about the implications of the second law of thermodynamics to the use of renewable energy for the world, so please bear with me. Here goes: Apart from the ...
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Why is the ground warm during winter and vice-versa?
I was just looking at the geothermal house heating in Iceland, and came to know that in the winter the water is warm, hence cools the house, but how is it hot, not about us feeling it.. My question is ...
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Ground source cooling -- why do you need the heat pump? [closed]
This answer says that the water from a ground source is always 50F. (I think this varies by location, but the concept is valid, anyway.) Why do we even need a heat pump? Why not just run that cold ...
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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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Energy lost to hydrogen fuel cell
So I have a question about an experiment we did in class.
We used a fan to blow air at a little wind turbine to generate electricity, we connected the turbine to a reversible PEM fuel cell to ...
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Is possible to generate energy from gravity?
When the wind goes through the vanes of an wind turbine, that energy is harnessed to generate electricity.
When the water goes through the water turbines, that energy is harnessed to generate ...
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Why do blades of windturbine propellers as comp. to propellers of ships cover very different areas?
This is a thought I asked myself often, but never did real efforts
to get an answer. Barsmonsters question about number of fans of a
wind turbine made me think of it again
Why do blades of aircraft ...
