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.

learn more… | top users | synonyms (1)

0
votes
2answers
217 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
votes
1answer
140 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 ...
4
votes
1answer
647 views

Wind Turbine Impact

OK, I'm not sure this is not a silly question, but here goes. I've often wondered what the impact is of wind turbines on the weather. My question is, since wind turbines transform wind energy into ...
0
votes
0answers
20 views

I want to charge 48V 108Ah battery from 48V 80Watt solar panel. Can anyone write that how much time will take this battery to fully charge? [duplicate]

Possible Duplicate: Charging 12V 150Ah battery I want to charge 48V 108Ah battery from 48V 80 Watt solar panel. Can anyone write that how much time will take this battery to fully charge?
5
votes
3answers
189 views

Wind's Sources and Drains (see live map!!)

I was pointed out by a friend to this website that shows live map of wind in US. It sometimes show interesting places where all the wind seems to converge and vanish. What's the origin of such "wind ...
2
votes
4answers
2k views

why ammonia is not a competitive energy carrier?

reading this article about Germany planning to store renewable energy as hydrogen gas, i'm left wondering why they deem so great this plan, compared with other alternatives like ammonia as a energy ...
1
vote
4answers
813 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 ...
3
votes
2answers
576 views

Russian Doll Teller Ulam?

Can you trigger a thermonuclear explosion from a smaller thermonuclear explosion in a scaling way, so that starting from a small laser ignited fusion within a small fissile container, using the X-rays ...
2
votes
4answers
1k 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 ...
0
votes
3answers
197 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 ...
3
votes
3answers
1k views

Would a thinner atmosphere (such as high altitude) yield better solar panel energy generation?

I am curious. If you were to put a solar panel up in high altitude or on the surface of the moon, both of which have much less atmosphere to reflect/refract light, would that solar panel produce more ...
1
vote
2answers
2k 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. ...
3
votes
1answer
161 views

Can a solar thermal collector designed for use in homes ever power a stirling engine designed for use in homes?

Can a solar thermal collector common on private roofs today designed for collecting heat for the household ever collect enough heat to power a stirling engine of say this model: ...
1
vote
3answers
251 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.
5
votes
1answer
706 views

What is the most efficient Organic Photovoltaic solar cell?

Preferably one that is researched in a paper, not necessarily in production. I have found various claims of OPVs with an efficiency of 10%, 8% and 7.3%, the only one I can substantiate is referenced ...
2
votes
3answers
2k views

How to calculate the temperature of a receiving point from concentrated solar power?

I'm exploring a DIY project about solar power and have found very few resources that can explain, in a not too simple but not too advanced way, how to go about calculating important values in solar ...
9
votes
3answers
248 views

What does the quantification of causes and effect look like, for clouds in offshore wind turbine wakes?

At Horns Rev windfarm off the coast of Denmark, sometimes in winter, clouds appears in the wake of the turbines. I've only seen photos of the phenomenon when the wind direction is exactly aligned with ...
4
votes
2answers
227 views

How much solar energy hits a rooftop in Israel?

I was asked to today about the available plans (in Israel) to install photo-voltaic receptors on the roof and sell the energy. This is a legitimate plan and there are several companies that do this. ...
2
votes
1answer
2k 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, ...
3
votes
4answers
7k views

What happens if a wind mill rotates in opposite direction?

Suppose if a windmill is made torotate in clockwise direction and due to air flow if it rotates in anti clockwise direction then does it produce electricity?
2
votes
5answers
36k views

Charging 12V 150Ah battery

I want to charge a 12V battery of 150Ah with a solar panel. The solar panel specs is 12V, 25 Watt. Can anyone please provide me how to calculate that how much time it will take to charge the battery? ...
3
votes
1answer
649 views

Why is E85 less efficient than straight gasoline?

Why is straight gasoline (or whetever the mixture was before the introduction of ethanol) more efficient (ie, more miles/gallon) than E85? I've known since it's introduction that E85 was less ...
6
votes
1answer
1k views

Would the ionic wind power fence actually work?

Described here and in the references (patent, patent), the idea is to use a large fence as a grid electrode. Spray water droplets near a high voltage to charge them, and then the wind blows them ...
1
vote
1answer
307 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 ...
4
votes
2answers
179 views

Solar chamber trapped light

Was wondering if trapping light in a reflective chamber could heat rods sufficiently enough to heat water? Trying to think of new ways in which we can utilise solar energy.
2
votes
2answers
389 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 ...
4
votes
2answers
252 views

Is it possible that windmills can consume the wind?

Can windmills allow us to consume (and, eventually, over-consume) the wind as a natural resource somewhat in the same manner that we are over-consuming many other natural resources?
5
votes
1answer
384 views

What type of solar energy technology has the most future potential?

In terms of dollars per watt, using theoretical efficiency limits, what technology holds the most promise to become the primary solar energy capture technology? My hunch is carbon-based modules, ...
6
votes
5answers
1k views

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 ...
36
votes
2answers
3k views

Wind generators - why so few blades?

Why commercial wind generators usually have just 2-3 blades? Having more blades would allow to increase power OR decrease diameter. Decreased diameter would also reduce stress due to different wind ...
7
votes
3answers
2k views

How do you produce electricity from a wind mill?

How does a spinning windmill produce electricity?What is the principle behind the windmill?
2
votes
2answers
750 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 ...
0
votes
1answer
222 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 ...
3
votes
2answers
415 views

Comparing Energy Technologies in terms of: Cost per Power Capacity and Research Spendings

Cost per Power Capacity For a number of energy technologies I'd like to know what the minimum costs are to install a given power capacity. Are there any such comparisons available? Research ...
17
votes
3answers
4k views

Are tidal power plants slowing down Earth's rotation?

Are tidal power plants slowing down Earth's rotation to the speed of the orbiting moon? (1 rotation per 28 cca days) Are they vice versa increasing the speed of moon orbiting by generating some ...
2
votes
6answers
1k views

What's the problem with solar energy?

What "breakthrough" from a theoretical point of view is needed for solar energy to become feasible energy alternative?
3
votes
3answers
521 views

How bright can we make a sun jar?

A sun jar is an object that stores solar energy in a battery and then releases it during dark hours through a led. Assume: a $65cm^2$ solar panel a 12h/12h light/dark cycle insolation of ...
7
votes
2answers
2k views

Does Tesla's photoelectric “solar cell” really work?

Tesla patented a device for gathering energy from light, using the photoelectric effect. (US 685,957 - Apparatus for the Utilization of Radiant Energy): Basically just a sheet of "highly polished ...
8
votes
5answers
1k views

What new breakthrough energy technologies are close to being realized? [closed]

Energy production is one of the burning issues for humankind. There has been some talk about future energy technologies including Fusion, Anti-matter annihilation and Zero-point-energy (from most to ...