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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2answers
597 views

What are the current possibilities for large-scale storage of electrical energy?

I'm curious as to how large-scale electrical storage is managed now, how much they can store, how well they scale and for how long (and what is their loss rate). (I'm not asking about technological ...
2
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2answers
721 views

Do wind turbines convert the kinetic energy of air?

It is often said that wind turbines convert the kinetic energy of the wind into electricity. But in respect to horizontal wind turbines with airfoil shaped blades this is imho not the case. Wind ...
2
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1answer
354 views

Solar energy and optical fiber

I'm not really good at science or physics, just wanted to ask about the idea (doesn't have an opportunity to test this). Will this scheme work and what can be its efficiency?(The goal is to make ...
2
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2answers
906 views

Limit on geothermal energy that could be extracted before the earth's magnetic field collapsed?

This is more of a theoretical thought-experiment question. Basically, how much geothermal energy can we extract before the loss of the magnetic field makes it a terribly bad idea? Will the ...
2
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4answers
2k views

Easy to understand equivalents for energy (kilowatt-hour)

Is there a database/webpage/other source for obtaining simple, easy to understand and meaningful equivalents for converted energy by a photovoltaic-site (Wh/kWh/MWh/GWh)? Something like "xxxkWh equals ...
2
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2answers
444 views

Small scale water power, how does water volume and hight convert into electric energy?

I was playing a little bit with the basic physics behind water power production but I can't get the numbers right. Let's say that I put a windmill that pumps water into a watertank on the top of my ...
2
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2answers
78 views

Why are large batteries described by their power?

Reading about renewable energy sources, I came across the idea to use huge batteries as a temporary storage to be able to deal with the fluctuations that e.g. solar panels might produce. The most ...
2
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1answer
98 views

How do wind turbines cause lightning?

I saw this paper about Lightning discharges produced by wind turbines More lightning strikes wind turbines than comparable non-moving structures. What would be the physical cause of this? Does it ...
2
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1answer
234 views

Could geothermal energy extraction in Yellowstone significantly diminish the threat of a supervolcano?

I recently read an article about a team in Iceland that had managed to drill directly into magma coming up from the earth's mantle, and then use the resulting bore-hole to generate steam to power ...
2
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1answer
3k views

Simple formula for liquid heat transfer

I'm trying to do a simple simulation of a solar panel coupled through some piping to a boiler, with the aid of a pump. My input constants could be something like: volume of liquid inside the panel, ...
2
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2answers
936 views

Rare earth minerals in solarcell production

When I was looking at photovoltaic solar cell production I saw that there was some difficulty with rare earth minerals used in the production but i can't find which rare earth minerals. I have tried ...
2
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2answers
209 views

How absorption coefficient determines which material is used to make solar cells?

Does the knowledge of the material absorption coefficients aids engineers in determining which material to use in their solar cell designs? If yes, how?
2
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2answers
2k views

In solar cells, do photons break apart electron-hole pairs, or create them?

Some sources say that when a photon hits the PV cell, it breaks apart electron-hole pairs. Other sources say that photons create electron-hole pairs. Can anyone explain which one is right? I've read ...
2
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0answers
53 views

Is it possible to generate usable electricity from the motion or magnetic field of the Earth? [duplicate]

Let me start by saying that my knowledge of physics is almost nil (only high school level and I pretty much forgot everything) so bear with me, if I am asking naive questions the answers of which may ...
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vote
1answer
645 views

Can capillary forces be used to make hydro electricity?

Could a device with very thin columns of glass or something that attracts water more be used to pull water up and then release it to drive generator and perhaps add vacuum. I have been wondering ...
1
vote
1answer
338 views

Energy storage and battery banks [closed]

Why is it not possible to store windfarm energy in battery banks? A lot of energy isn't being used when wind farms are at peak and we have no way of storing it. This is wasteful. So why don't we use ...
1
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1answer
644 views

Is Ronald Ace's “solar trap” patent plausible?

This newspaper article and a few others from last year discussed a patent by independent US inventor Ronald Ace. It's about a kind of absorber for solar thermal energy systems, and it's supposed to ...
1
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3answers
286 views

If humans were able to catch all sun energy reaching the earth for their use, will the climate change?

I guess that energy will be used up and, at the end, will contribute to heat the earth, so I see no big differences... please explain your point of view.
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8answers
463 views

Why not use our own light production to produce new energy instead of wasting it?

Why don't we use our own light production at night (I mean home, buildings, streets,..., lighting) to charge photovoltaic panels instead of wasting it?
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1answer
60 views

Why does solar cell will create as a Multiple cells instead of one large cell area?

Why is a solar module assembled from multiple cells instead of one large cell area?
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1answer
52 views

How is the kinetic energy of the wind transferred onto a lift based wind turbine?

The rotor blades of a lift based wind turbine are shaped like airfoils, so the wind flowing around them creates a lift force which in turn moves them around. From a thermodynamic viewpoint and like ...
1
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1answer
74 views

Photovoltaic IV data

I am looking for any available measured solar-cell datasets (Voltage/Current) especially for organic photovoltaic cells for the testing of a software unfortunately I am unable to get the measured ...
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2answers
347 views

Do bifacial solar panels operate at lower temperature than normal solar panels?

Bifacial solar panels have a glass backplane instead of the usual aluminum and are designed to absorb and convert to electricity light incident on either face. Many manufacturers claim that their ...
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3answers
3k views

Can energy be extracted from clouds?

Can cloud charge imbalance be used as an energy source? First off quite some energy must be present in clouds: a lightning path is quite long, and electrical breakdown of air requires about 1MV/m. ...
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0answers
39 views

Wind turbine design question [closed]

I am planning to design a wind turbine that is has rotor blade radius of 0.915m and is connected to a generator. The generators specifications are, it is an ac generator with 5000 coil turnings and a ...
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0answers
18 views

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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0answers
24 views

solar energy on a specific location

How to find the amount of solar wattage in any specific place on earh in a monthly manner? by solar wattage I mean the energy recieved from the sun in a squared meters.
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1answer
55 views

What mechanism can we use to convert waves energy?

In term of renewable energy, can we use waves as another energy that can be stored and used instead of solar, wind and etc ? What I mean here is not sea waves but another kind of waves such as radio ...
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0answers
45 views

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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4answers
862 views

Expected Energy Production From High Efficiency Solar Cells

First, a bit about my thoughts. I believe we have the capability today to provide energy, water, food, education, and transportation to every man woman and child on the planet. To that end, I would ...
0
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6answers
12k views

Is it possible to generate electricity using a water tower?

Is it possible to build a water tower that will provide enough pressure to run an electricity generator? A water pump can be used to send water up to the tower. The water pump can be powered by solar ...
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3answers
237 views

Lightning Power?

What is the power source of a lightning? It doesn't consume fuel, nor an atomic fission/fusion, but it discharges a large amount of energy. Is it feasible to create an artificial lightning using the ...
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2answers
245 views

Is a photovoltaic cell on an artificial satellite the same construction as one used on Earth's surface?

Are photovoltaic cell arrays on a satellite the same that are used within Earth, or is there some difference in their construction given the differing environment in which they are to operate? Does ...
0
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3answers
304 views

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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1answer
153 views

Do you think it’s possible to make a power plant of the described kind?

We are working on a science project and try to engineer a power plant of a new kind. It is called Air HES (air hydroelectric station). The idea is described on our website. Do you think it is ...
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2answers
49 views

which is efficient on solar electricity by photo voltaic or thermal

As we know solar energy used to generate electricity in two major ways: photovoltaic and thermal energy. The most small applications or personal use are mostly using solar cells. But when it comes to ...
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1answer
247 views

Can we make a “Gravity Mill” based on principle(s) of Newton's cradle?

DISCLAIMER: Newbie/Wannabe Physicist. What's to stop us from making a "Gravity Mill" which is a bar/rod attached with weights on both ends and pivoted at the ...
0
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1answer
47 views

How to calculate power necessary generated from wind turbine to run a motor

I was making a small/cheap wind turbine, and I am stuck on how to calculate the power needed (speed of wind) to run a brushed motor (since I figured that would be the easiest to run with rotor blades ...
0
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1answer
167 views

If human energy use were to increase by 2.3% per year, would we use all solar energy by 1400 years?

Assuming 2.3% per year exponential growth of human energy consumption (so, roughly speaking, that corresponds to multiplying consumption tenfold every century), it's argued that human annual energy ...
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2answers
280 views

Solar Thermal/Solar Photo-voltaic calculations [closed]

This is my final high school assignment. I'm asked to prepare a research document on Solar Thermal and Solar Photo-voltaic, to prove that these two are feasible alternative power sources to power the ...
0
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1answer
17 views

Attracting atmospheric positive ions to carbon nano tubes for collection

Can nano magnets built into carbon nano tubes be used to attract moving positive ions from atmosphere to increase the resultant positively charged collecting mass?
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2answers
55 views

Is the amount of hydro-electricity harvested, proportional to the number of turbines? [closed]

I've looked on this site and people have said that it wouldn't make more energy that it would cost to have water turbines on a water tower. But if it only takes say three pumps (I don't know what it ...
0
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1answer
303 views

Can magnetic energy be used to create a magnetic motor which can power vehicles and machines? [closed]

Can magnetic energy be used to create a magnetic motor which can power vehicles and machines?
0
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1answer
227 views

What is it that makes this structure cause turbulence?

I'm trying to design a quasi-simple vertical axis wind turbine, and a coworker came up with this design to focus the wind as it reaches the turbine in a wind tunnel. He says that there's going to be ...
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0answers
19 views

Is there a temperature drop at the rotor plane of a wind turbine?

A wind turbine rotor produces power from the torque generated by the rotor blades. This torque arises from forces on blade elements which in turn are the consequence of pressure differences on each ...
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0answers
23 views

How to calculate theoretical power generated depending on temperature

I know the current technology of gas turbine and how they use extremely hot gases to generate power. However, if there was no combustion and compressor system associated with the gas turbine, how can ...
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0answers
19 views

how to calculate Cp of wind turbine

I am having trouble calculating C$_p$ of my wind turbine The radius of my rotor blade is 4.5 inches and it's rotation per second is 10 (10 rotations per second). So I found my tip speed of blade ...
0
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1answer
22 views

What parameters decide the maximum concentration achieved by a fresnel lens?

Fresnel lens can be used for concentrating sunlight for Photovoltaic. What parameters of the lens decide the maximum concentration that can be achieved using the lens.
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0answers
11 views

What is the distribution of a battery transmission?

I have an energy-harvesting battery attached to a node, transmitting data over Rayleigh flat fading channels. Energy in the battery is used, and simultaneously energy is harvested and stored. I want ...
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0answers
26 views

Karman Vortex Street phenomena to turn mechanical energy into electric energy at nano to mm scale?

How can one determine mathematically if it is practical to use the Karman Vortex Street phenomena at a nano scale or mm level to harness the wind's mechanical energy via a carbon nano tubular ...