Questions tagged [renewable-energy]

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

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Where are the energy losses here?

This hydroelectric system, described in The Study of Syphon and Applied in Hydroelectricity Power Production, is said to be continuous once it has been set up. Once set up it is claimed that it will ...
n7unity's user avatar
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CNC a hemisphere in SolidWorks

Dear all, I am currently learning CNC Milling software. I have successfully be able to simulate the toolpath for milling a square block to a hemisphere. May I ask how to add another operation, that is ...
Maximus Su's user avatar
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Energy balance of "air-gen" direct water vapour to electricity generation

I've just read this article on a new - albeit very small scale ATM - way of generating electricity directly from water vapour: https://www.theguardian.com/science/2023/jul/02/it-was-an-accident-the-...
Damian Birchler's user avatar
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2 answers
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Can I be mostly dependent on solar and batteries? [closed]

Plan A: Ask your neighbors to give you permission to install solar panels on their roofs (ofcourse you can manipulate them into saying yes by giving them money once off ) So Ask your neighbors to give ...
Bheka Majola's user avatar
2 votes
2 answers
87 views

Can we create electricity through an hourglass?

So imagine this, an hourglass that is the size of a two storey house in height but is wide as an average sedan car that can trickle sand for 5 hours, and at the middle there's a gear which is turned ...
Bheka Majola's user avatar
3 votes
1 answer
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What mathematical operation should I do in order to translate from TWyr/y to TWyr_30 in this article?

In this article https://www.sciencedirect.com/science/article/pii/S266711312200002X the authors show a result of prediction on energy reserves (in particular solar ones) as known in 2015 (Figure 1) ...
Mathieu Krisztian's user avatar
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Would it be possible to harness the energy flow from a continuous water system?

I’m working on a project to put Archimedes screw turbines into drains and sewerage water. However, as an experimental project I wanted to test out an idea to evaluating turbine degrees and flow rate ...
Suzie's user avatar
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wingrotor rpm regulation; wind turbine regulation mechanism how it works?

First figure-Fig. 23. Regulating wingrotor, rotating in feeble wind, wingspan fully open. Second figure-Fig. 24. Regulating wingrotor, rotating in strong wind, wingspan contracting. ...
technik4's user avatar
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2 answers
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Can ocean flows after a crashing wave be accumulated in one point to increase the water height of that location?

Here in this image, you can see the water flow onto the beach to a certain distance. After a while, the water retracts back. If I put a V-shaped collector (like a vertical standing open book) facing ...
ARJ's user avatar
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5 answers
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Are there any ad-hoc uses for electricity that we can divert excess energy to when renewables are peaking?

My idea is this: divert excess energy that comes from peak renewable energy production to ad-hoc public works whenever we have more than we can put in batteries. I just don't know what things like ...
Tyler Cheek's user avatar
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2 answers
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Can the crest of an ocean wave be increased by directing ocean waves to a center of a curved column?

My question really pertains to improving the oscillating water column device to generate greater electricity. The way the current system works, when a wave with a crest hits the wall, the water inside ...
ARJ's user avatar
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1 answer
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Which are the Betz's limits for marine devices such as wave energy converters?

Nowadays, climate change is a relevant topic to reflect on the uses of renewable energies, such as the Sun, wind, oceans, tides, etc. Engineers are trying to design devices to extract the most power ...
Luke Solo's user avatar
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1 answer
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Is there any technical bar from restarting the nuclear power plants of Germany?

Any that makes it impractical or, yet worse, impossible? If no, how long should it take for Germany to get them back online?
DeadStream-2's user avatar
2 votes
4 answers
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Different equations for Hydropower

I was doing some reading in hydropower and I came across these two power equations: $$P = ρghQ $$ and $$ P = QHg $$ Q is flow rate, ρ is water density, g is gravity, h is height, and H is head. I do ...
RSM's user avatar
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Does a fully mechanical heat pump make sense?

Is it reasonable to operate a fully mechanical heat pump? For example, using a linear back-and-forth motion from a vortex bladeless turbine to operate a mechanical compressor to heat (or cool off) a ...
mricon's user avatar
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Is it better to charge my electric car on windy days?

There are various dashboards (for example, here) that show the current energy generation mix and the overall CO2 emissions (gCO2/kWh). In the UK renewables can make up a large proportion of the total, ...
Gransden's user avatar
2 votes
1 answer
355 views

How large would a solar panel array need to be in order to supply all the world's energy?

This story from 2016 claims that all the world's energy needs could be supplied by covering 1% of the Sahara in solar PV panels. Was (is?) this true, and if not, how would you go about approximating ...
tomh's user avatar
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Can tidal turbines be used as run of the river generators

I see that the British government is supporting a project to generate energy using tidal turbines. I am wondering if the same design would be effective and economic also for run of the river power ...
FluidCode's user avatar
2 votes
2 answers
362 views

How do 3 blade turbines come so close to the Betz Limit?

I have seen many diagrams (see attached) that indicate that modern 3 blade turbines are nearly 50% efficient, which is about 80% of the Betz limit. Betz calculated his limit based on a theoretical ...
Sanjay Jain's user avatar
1 vote
1 answer
29 views

what are some books/academic journals which I could read on renewable energy/technology? [closed]

Book suggestions on renewable energy technologies/sources
Arabella's user avatar
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2 answers
200 views

Assessing flow rate from open sea into a container

I'm currently assessing sub sea pumped hydro capabilities, and need to use the flow rate in order to calculate power output. I can calculate the energy storage capacity using E = mgh: $E=mgh = ...
Kuriosity's user avatar
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1 answer
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I want to determine the flow rate and required turbine size for an offshore hydroelectric scheme and need help

I'm creating a report on the possible implementation of a sub hydro system and need some help. I've attached the image of what I'm proposing, where I've essentially created a head via a riser B with a ...
Kuriosity's user avatar
1 vote
1 answer
31 views

Statistics on energy mix in Europe [closed]

Does anybody know where to find statistics on the energy mix in Europe (preferred by country)? I can only find the share of renewables. I'd like to see the whole mix with a split into energy sources (...
gumpel's user avatar
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3 answers
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Correct wind Weibull distribution for wind+solar system

I'm trying to forecast the peak power output for a wind + solar system. The solar output as a function of time of day and month can be forecasted easily. I also have the historical wind speed for a ...
hurreechunder's user avatar
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How energy intensive is creating artificial islands in the IJsselmeer?

The City of Amsterdam is building a series of artificial islands for new housing. One of them is Centrumeiland. Its size is 13 ha. (130,000 m2). Its creation requires 800,000 m3 of sand (Source), i.e. ...
sba222's user avatar
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2 answers
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Can lithium ion batteries solve the world's energy storage problem? [closed]

This questions boils down to the following important questions: Do we physically have enough materials in the earth's crust to make enough lithium ion batteries to support global storage demand? Can ...
gstudent's user avatar
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0 answers
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Shadow flicker validation

I am currently trying to validate a shadow flickering algorithm against some data generated by Openwind. The goal of this validation is to have a code that we know that is correct and modify it to ...
Lucio Carlos Pimentel Paiva's user avatar
-1 votes
1 answer
464 views

Capacity credit vs capacity factor

What is the difference between capacity factor and capacity credit? I know that capacity factor = annual generation / (installed capacity * 8760) but I don't understand how capacity credit is ...
Clone's user avatar
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1 answer
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Why Do Airborne Wind Energy Systems Use Kites And Not Balloons?

Title says it all, Why are AWE-companies like Makani spending years and millions of dollars developing drones, rather than simply using a balloon-based design? Wouldn't it be easier and faster to get ...
GeorgeWTrump's user avatar
4 votes
2 answers
660 views

Advantages of hydrogen gas turbine over fuel cell

In the setting of large-scale electricity generation, I was wondering why one would want to burn hydrogen in a gas turbine instead of using it to power a fuel cell. Aren't fuel cells more efficient ...
Damian Birchler's user avatar
2 votes
0 answers
44 views

Increase in target emission rate (TER) when using a air source heat pump (ASHP) in standard assessment procedure (SAP) calculation

I am running a SAP calculation on a proposed building which will be utilising a 8.5 kW ASHP for space and water heating. I am also running a comparative analysis against a mains gas boiler to show the ...
H.B. Finn's user avatar
-1 votes
2 answers
86 views

What is and how do you calculate the wind velocity design for wind turbines?

I am finding it difficult to get consensus on the definition of design wind speed for aeolic turbines. I thought it was the velocity that corresponds to the maximum power output, but I have already ...
Vitor Aguiar's user avatar
7 votes
7 answers
7k views

Why is hydro-electric power still scarce in some places?

70% of the Earth's surface is covered in water, why can't a hydroelectric power plant be set up on each and every river? Is it that its too expensive? Why is electricity still a problem in countries ...
Sristy's user avatar
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2 votes
4 answers
3k views

Why aren't gravity batteries everywhere?

The problem of energy storage, especially with regard to renewables, remains unsolved. Or at least there do not seem to be any popular solutions. Why not gravity batteries? I love the idea, and they ...
SuaveSouris's user avatar
1 vote
1 answer
106 views

How to estimate wind generation using power curve?

I am trying to verify windfarmer generation estimates manually. To do so I am trying to manually calculate the estimated energy production (kWh) of a wind turbine. The information I have available is ...
Bobby Heyer's user avatar
2 votes
3 answers
152 views

Wind turbines with down tower power units. Why aren't they more common?

Concerning the big megawatt wind turbines, if there is such a big trouble with gearbox bearings failing much earlier than expected and costly maintanence or replacement of huge gearboxes, what is ...
Xynon's user avatar
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3 votes
1 answer
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Clutch role in a micro hydropower

I've recently visited an old (about 60 years old) micro hydroelectric standalone installation. Total electric power is about 3 kW A/C. A local told me between generator + fly-wheel and turbine there ...
mattia.b89's user avatar
1 vote
2 answers
89 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 ...
MacIomhair's user avatar
0 votes
0 answers
227 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 ...
rollsch's user avatar
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1 vote
2 answers
237 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 ...
Thaina's user avatar
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0 answers
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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 ...
Shobhit Singhal's user avatar
1 vote
0 answers
31 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 ...
Ivan Mejico's user avatar
0 votes
1 answer
39 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, ...
IK-_-IK's user avatar
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0 votes
1 answer
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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 ...
R. Theaker  CD's user avatar
2 votes
1 answer
97 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?
energy's user avatar
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-1 votes
1 answer
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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 ...
user109474's user avatar
0 votes
2 answers
641 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 ...
calm-tedesco's user avatar
3 votes
1 answer
801 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?
user473180's user avatar
2 votes
1 answer
536 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 ...
ye-ti-800's user avatar
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0 votes
3 answers
104 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 ...
Joshua Utting's user avatar