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Questions tagged [renewable-energy]

Questions related to energy produced by renewable systems such as solar, wind, water and geothermal.

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1answer
42 views

Can a bridge's towers be used as wind turbines?

I come from a fairly remote island where we need a 150 min ferry ride to reach the mainland. While the island has few resources that would encourage a government to investigate the possibility of a ...
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0answers
26 views

Can a Tesla Powerwall 2 be rate limited?

Can a telsa powerwall 2 be rate limited (discharge/charge)? I have access to realtime electricity rates (30 min update interval) and also access to 12 hour predicted look ahead. So I wish to limit ...
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2answers
63 views

Why vertical wind turbine don't be half covered

I think it would be more efficient for a vertical wind turbine to have a covered funnel about half of it Something like this figure It would protected the turbine from opposite wind and also ...
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0answers
30 views

Designing a piston pump for windpump

I am designing a savonius type wind pump for low wind speeds(avg speed = 2.7 m/s), with these speeds and rotor area of about 2 m2. Acc. to my calculations, I am getting a volume flow rate of ...
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0answers
22 views

Hybrid Energy Monitoring Systems

I have been doing research on renewable energy systems and I must admit that I am a newbie in this specific area. I have noticed that stand-alone systems have their own specific monitoring system ...
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1answer
25 views

Qualitatively how does the O-wind turbine function?

Recently the O-wind turbine won the James Dyson award for innovation, the item is essentially a compact wind turbine which unlike traditional wind turbines can harness wind from multiple directions, ...
1
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1answer
38 views

Solar Thermal heat gain formula converted to CO2e and trees saved

We have invented a solar thermal heating system with interseasonal storage, recently patented. I want to display the trees saved and carbon offset on the control display based on temperatures coming ...
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1answer
37 views

Converting grams of fuel per kWh of energy

Is there a database showing how many grams of a particular fuel generates how many Kilowatt hours of electricity?
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1answer
29 views

Why do pumped storage hydroelectric facilities use bent pipes? [closed]

When a reservoir is used to store water for electricity, it's pipes are usually laid in several segments on the ground to reach its source, such as a lake. It seems that if the pipes went directly to ...
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2answers
386 views

How is the energy production of solar and wind compared with the prospect of nuclear fusion? [closed]

I am trying to find reliable information and comparisons about the energy production of renewable energy technologies, specifically, how solar and wind alternatives compare to nuclear fusion. Why is ...
2
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1answer
261 views

CUF v/s PLF of power plants

What is the difference between capacity use factor (CUF) of solar power plant and plant load factor (PLF) of coal based power plant? Can we compare both since they seem analogous?
3
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1answer
128 views

How do you calculate the Enthalpy of a geothermal resource?

Enthalpy seems to be commonly used to characterize geothermal reservoirs, but how is it calculated? I have an example here where the enthalpy is cited as 800 $kJ kg^{-1}$ for a reservoir with a ...
0
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1answer
47 views

Feedback on idea for a power station

Hi there, When I was very little I came up with this idea for a power station and I recently remembered it and was curious about the viability. The way it works theoretically is that a voltage supply ...
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4answers
152 views

Are abandoned nuclear smoke stacks strong enough to be filled with water (for pumped storage)?

I noticed that there are a growing number of abandoned stacks of this type: Image source. I wonder if they are physically strong enough to hold water, for use in pumped storage:
0
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1answer
49 views

How many batteries can I charge and how long would it take?

Using a hydro generator which gives an output of 4.838KW, I am trying to figure out how many batteries I can charge and how long it would take. I am doing the calculations based on 12V, 17Ah ...
0
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2answers
94 views

Can you use the kinetic energy of air to power a car?

In my fluid mechanics class, I've learned that a fluid traveling in a pipe will generate a force when the exit area is smaller then the entrance area. Suppose a pipe is attached to a car that will use ...
0
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1answer
78 views

Generating power from fruit

Is it possible to generate power from fruit juice, using a device with a simple circuit which charges a battery using juice from fresh oranges? If so what would be the ratio between emf emitted and ...
0
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1answer
54 views

What is the exact definition of renewable energy [closed]

I was wondering, in laymen terms, what is the exact definition of renewable energy and what are its various forms, which ones are better and in what situations can they / can they not be used. How do ...
2
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4answers
1k views

What is the theoretical maximum energy efficiency of hydro turbines?

From what I've read it seems that hydro turbines can theoretically achieve 100% energy conversion from kinetic to electrical energy. However, I just wanted to double check if this was true.
3
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0answers
30 views

Parameter effects on kinetics of esterification for bio-diesel production

I want to discuss the effect of parameters on the kinetics of esterification for bio-diesel production. In esterification process, temperature effect and molar ration are two important parameters. ...
7
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2answers
579 views

Why don't we just build a giant wind turbine?

The power generated by a wind turbine is given by: $$\mathrm{Power} = \frac{1}{2}C\rho AV^3$$ Where: $\rho = \text{Air density}$ $C = \text{Coefficient of performance}$ $A = \text{Frontal area}$ $V ...
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1answer
115 views

What theoretical efficiencies can wind / hydro turbines achieve? [closed]

The high water has some energy E = mgh. In the basic school, we were told that hydropower plants extract the energy of "falling water". Now, that banned principle says that if your water falls upon ...
11
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7answers
4k views

What are the disadvantages of concentrated solar thermal power?

Concentrated solar power looks on the surface to be an excellent source of grid power. It's sustainable, has no obvious waste products to deal with either during construction or operation, and with ...
4
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2answers
3k views

Relationship between wind velocity, turbine rotor diameter, and power output

I'm trying to understand and identify the equations to use in defining the relationship between wind velocity, turbine rotor diameter, and power output for a wind turbine. To simplify my question, ...
3
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1answer
134 views

What is the power and max flow rate required to rotate a 300 W wind turbine?

I have purchased a wind turbine with a power of 300 W, the start up wind speed is 2.5 m/s, rated wind speed is 11 m/s, and the survival wind speed is 45 m/s, and what I'm going to do is to make an ...
2
votes
1answer
483 views

How to get the maximum power point from I-V curve for Organic Photovoltaics (OPV)?

I am taking organic solar cell course on Coursera, and I have a question about I-V curve for a certain solar cell. The question asks for the solar cell characteristics such $V_{oc}$, $P_{max}$ and $FF$...
5
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1answer
77 views

To what degree are wind and water turbines exchangeable?

Assuming maximum efficiency is not the primary concern (but net positive efficiency is), to what extent could a wind turbine operate in water and vice versa? How do the different turbine types fare ...
3
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1answer
75 views

Could future fusion energy exist without the input of any petroleum or natural gas products?

Given a successful deuterium-tritium fusion reactor such as that conceived by ITER, could the world's energy needs theoretically be met without the input of any petroleum or natural gas products? ...
2
votes
1answer
116 views

Calculate energy (kW, or kJ) from Vapour Expander Generator

I'm a student of Integrated Water Management, and looking at a geothermal bore that is producing potable water for a town's water supply. The bore water reaches the surface at $50$ $^oC$, and flows ...
5
votes
2answers
717 views

Is the fill factor of a photo-voltaic cell constant?

An important factor in specifying the efficiency of photo-voltaic (PV) cells is called the fill factor (FF). It is defined as the ratio of the maximum power of the cell to the product of the open-...
22
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5answers
6k views

Why don't hydroelectric plants use cascades of turbines instead of single turbines?

In a gas turbine engine there're multiple sets of blades - one set after another and combustion products pass all the sets and each set of blades gets some of the power. This increases utilization of ...
5
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1answer
108 views

Do regulations in the United States limit the size of aerial wind turbines?

What with all the work done by the FAA recently on regulating drone usage, I thought it would be nice to turn my eyes to the sky for another, less-known type of aerial denizen: the aerial wind turbine....
12
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2answers
225 views

How to correctly size the blades for a small educational wind turbine?

I want to design a small wind turbine that can be easily carried out of the classroom into the sports field in relatively low-wind conditions (5-15km/h) that can power a small ultra-bright 5V LED - ...