Questions tagged [renewables]

a resource that can be created or used over and over again without depleting the materials from which it is made.

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2answers
60 views

Why create green hydrogen using renewable energy? Why not directly use electricity from Renewable sources?

We generate "green hydrogen" using electrolysis of water which is powered by Renewable energy sources like Solar Panels, Wind mills, Hydro power etc. When we obtain such hydrogen and store ...
15
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8answers
8k views

Why don't they make playgrounds generate electricity?

Why don't they make playgrounds generate electricity (at least, not on a large scale)? It's a pity that all that energy of children horsing around goes to waste instead of being harnessed. You could ...
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2answers
63 views

grid-based gravity assist power generaiton

I was discussing with a friend about renewable resources in which you can generate and store power for a long time. In this one way which I know is hydropower where when you have huge requirement of ...
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1answer
43 views

Shading percentage to cause hot spots

I'm designing a solar plant over the roof or a huge building for my company. Now the roof has a lot of obstacles, Shafts, pillars, AC equipment etc. I have a couple of questions that I could really ...
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1answer
64 views

Could multiple ram pumps be used to fill a watertower for a pico hydroelectric system?

Since a watertower stores potential energy just like a reservoir does for a hydroelectric dam, could I use that to power a pico (<5kW) hydroelectric system for my homestead? Now, I have read that ...
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0answers
34 views

How much renewable energy is curtailed around the world?

CAISO, the California electric grid operator, provides daily and historical reports on wind and solar curtailment: I started looking for similar data from MISO, the grid operator where I live, ...
3
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2answers
96 views

Will negative power pricing counteract the growth in solar PV capacity?

In California, the real-time electricity prices routinely go negative. Here's pricing for the four load aggregation points for California on April 1, 2020 (source): This is due to the large amount of ...
4
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1answer
67 views

How much land needed to dispose of blades from wind turbines?

I saw a news article saying that Wind Turbine Blades Can’t Be Recycled, So They’re Piling Up in Landfills. This is definitely unfavourable, but I really want to get a better sense of the scale of the ...
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1answer
43 views

Source for share of renewable energies in the electricity production of Europe

I am looking for a source that shows the development of the shares of renewable energies in the electricity production in Europe. I only found statistics about the share for the end energy consumption ...
5
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2answers
133 views

Is an incrementalist approach to decarbonisation feasible?

There seem to be two broad approaches to the climate crisis. One centres around technological progress, where efficiencies, a gradual switch to renewables, and CCS enable a broadly similar model of ...
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1answer
75 views

Is there any case where plant farming is more eco friendly than raising livestock?

I am looking for an example or a case with arguments that would justify converting cattle ranches into plant farms (e.g., wheat, apple, or anything non-meat). The advantages should be in a more ...
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1answer
84 views

Is the cost of non-fossil fuel LCOE misleading?

Natural gas is a waste product. Its "cost" is almost entirely profit. All renewables can do is compete down this margin, they can never beat gas. If renewables are cheaper that just means some ...
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2answers
369 views

Do electricity generators that run on methanol exist?

Methanol is probably the easiest burnable fuel to produce that is also sustainable. I'd like to produce electricity from methanol, using a device I'd call a 'Methanol Generator' - but I am struggling ...
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2answers
43 views

Reducing/Offsetting Impact of New-Build Home [closed]

So, here's a breakdown of the question. Situation: In the next month or two I will be moving house to a new-build detached house in the UK, which is on an estate of around 100 similar such properties....
2
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2answers
116 views

Why do some people say that biofuels are renewable energy source if producing biofuels requires nitrogen fertilizers?

Why do some people say that biofuels are renewable energy source if producing biofuels requires nitrogen fertilizers that are produced from natural gas (and energy output of biofuels is less than that ...
5
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1answer
105 views

Is electricity used at night more likely to be renewable?

Discussing charging my electric car with a colleague recently I argued that since (in Ireland) our renewable energy sources are mainly wind and hydro, since I charge my car at night the mixture of ...
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1answer
194 views

Is it possible to harvest energy from the storm?

My idea of a device for harvesting energy from wind If used in reality, this device will harvest significant amounts of energy from wind, waves and storms. This not only solved the problem of energy ...
4
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1answer
102 views

Which measure of solar irradiance is needed to calculate the energy output of PV systems?

According to "E = A * r * H * PR" global formula to estimate energy generated, the solar irradiance value is needed. I have Horizontal irradiance, Tilted irradiance, and Normal irradiance values but ...
4
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2answers
51 views

Is there a simple on-line tool for estimating wind turbine power output?

The back-and-forth in the comments on this answer sent me searching for a simple tool that would enable a user to put in a location, wind turbine size, and a few other parameters, in order to estimate ...
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3answers
284 views

Are trees more productive than wind turbines?

Tree farm assumptions: 250,000 square meters (m2) tree farm A 1 ton tree contains 1 MWh of energy Each tree takes 10 m2 of space Total energy for this farm is thus 25 GWh Wind farm assumptions: 5 ...
4
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1answer
488 views

Will natural gas or propane generators also run off of methane?

I'm looking at building a sustainable energy project that will convert biogas (methane) into electricity. I haven't found any biogas or methane electric generators for sale. It seems that there are ...
5
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3answers
67 views

Cost benefit analysis of a PV array with racking to set optimal angle, vs a larger array

I'm thinking of installing some panels on the roof. It's unshaded but only pitched at 5 degrees on long run roofing iron. Would I be better off racking at an angle to optimize for winter sun, or just ...
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0answers
66 views

Are there any articles that describe to correlation between the forecast errors for renewable energy resources, depending on the distance?

In an article by Zhang et al., the authors describe how the (normalized) forecast errors of different renewable energy sources (like solar panels and wind mills) are correlated. To that end, they ...
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1answer
242 views

Is it possible to reverse the air flow of a roof turbine/whirlybird?

I am currently working on a device that requires omnidirectional air currents (e.g. breezes/winds) to be directed downwards through a vertical tube. I think it would be a very similar design to a ...
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3answers
1k views

Is solar energy the best renewable source of energy?

Here is my thinking on renewable resources. Biomass is the absolute worst way to go because it releases CO2 and damages habitats. Geothermal is not far behind but is for a different reason. ...
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0answers
70 views

Calculating wheel and motor size for run-of-river hydroelectric generator [closed]

I am a student designing a hydro electric generator used on rivers to collect kinetic energy from horizontal water flow, rather than potential energy from vertical water drops. My idea is to turn a ...
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2answers
350 views

Are RECs (Renewable Energy Certificates) an effective method to "green" industry?

Chris Goldie's answer to a question on sustainable web infrastructure brought this question up. From the US Environmental Protection Agency: A renewable energy certificate, or REC (pronounced: rěk)...
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3answers
142 views

Is "renewable" a proper term for both solar and hydro power?

The common definition for renewable energy sources includes at least: Wind Solar Biofuels Hydro Geo-thermal However, the common definition of renewable makes this grouping a bit awkward. Webster ...
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1answer
105 views

Should we leave all fossil fuels in the ground and not use them?

I get the feeling that there is such a strong backlash against fossil fuels that there is an irrational movement to purge them completely. Maybe because people are transferring their worries about ...
3
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1answer
104 views

What is a good database containing wind speed and direction?

I am pursuing a science project involving wind power, and am looking for some data on wind speeds, directions, and ideally turbulence and shear. Do you know where I could find this? I would need to ...
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1answer
182 views

Is a master's degree in computer science relevant for working in sustainable living?

I'm currently at the end of computer science bachelor and not quite sure what to do after. In a way I'd like to continue with a Master's degree and at the same time help somehow for a more eco-...
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1answer
89 views

What metrics are usually used to quantify forecasted power error for weather-dependent renewables?

What metrics are usually used to quantify forecasted power error for weather-dependent renewables such as wind or PV? I guess that there are at least two kinds of errors: where the magnitude of the ...
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3answers
162 views

How the grid is managed in markets with high renewable energy penetration

As many people know, many of the renewable energy technologies generate fluctuating power dependent on availability of the power generating source e.g. wind and solar et al. Balancing power must be ...
5
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1answer
34 views

How accurate are consultant pre-construction energy assessments?

For power plants where the energy that could be generated is driven by exogenously variable factors, such as wind farms, PV power plants, and run-of-river hydro, which are all driven by weather, how ...
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1answer
68 views

How are readings from the wind sensors mounted on wind turbines influenced by the blades' wakes?

Utility-scale wind turbines have various sensors mounted on the nacelle, to ensure the power generation is optimised. How are readings from the wind sensors mounted on wind turbines influenced by the ...
4
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1answer
568 views

What does the P90 of a wind resource mean?

I've heard that investors use the P90 of a wind resource when considering an investment. What kind of measure is it, what does it actually mean, and how is it calculated?
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0answers
30 views

Which part of the process of estimating wind resource has the potential greatest benefit from further research?

Estimations of the potential generation resource of wind power happens at all scales from very coarse global estimates, to detailed estimates at individual sites based on specific locations and ...
4
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1answer
103 views

Is there a recent study that shows how accurate wind turbine wake models are?

Wind-turbine wake models are used in the design of wind farms, to optimise the choice of turbine model, and the layout of the turbines. They're also sometimes used in the operation of wind farms, to ...
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3answers
4k views

What's the average efficiency of pumped hydroelectric energy storage facilities?

Pumped hydroelectric storage has, to date, been the most scalable way to store electricity (in this case, in the form of gravitational potential energy), allowing us to spread the time between when ...
5
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0answers
177 views

What are the advantages and disadvantages of using lidars over sodars for wind resource assessment?

The process of wind resource assessment has used a variety of methods over the years; more recently, lidar - radar-style sensing using lasers; and sodar (similar, but using sound) have come to ...
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1answer
109 views

How close are renewables prices to scrap value?

I suspect that it's less than a factor of two. Is this right? A 1 kw panel has 10kg of silicon at $20/kg. That's $200 for a panel that costs less than $400, at 34 cents/watt. A 1.5mw turbine has ...
2
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1answer
54 views

Are Eco-Schools more effective teaching children about sustainability?

Is there any evidence that Eco-Schools are better at building sustainability awareness for school kids and teaching them about renewable energy technologies? Or is there a better approach that might ...
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1answer
236 views

Does a PV panel take more energy to build than it generates in its lifetime? [duplicate]

Industrial energy costs are $1 per million BTU (MMBTU) or 300kWh, or $3*10^-6 per watt hour (Wh). http://www.eia.gov/consumption/manufacturing/ Solar has 1 kg of 9n silicon per 100W, at $20/kg. ...
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3answers
162 views

Is pellet fuel a sustainable energy source in the way it's used now?

Pellet fuel is considered a sustainable energy source. But the way it's used now seems to produce air pollution which I think should not happen in case of sustainable energy source. So is pellet ...
5
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1answer
144 views

Hydro-electric generation from roof-collected rainwater

Can electricity be produced from running water by the use of dc motors? For example rainwater collected from from the roof of a very tall house say 15m high is directed through a pipe and at it's exit,...
6
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1answer
107 views

Are there different types of water-source heat pump?

I have heard multiple names for water-source heat pumps. What's the difference between something called a water-to-water heat pump, and a seawater heat pump? Are they just different names for the same ...
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1answer
93 views

What is the difference between Geothermal HVAC and Heat pump?

What is the difference between these two renewable energy air conditioning systems?
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1answer
74 views

Solar Panel short section of string due to obstacle

Recently I have installed a set of 10 panels connected in series with 1 single Inverter. I have realised that for the first 2 hours 2 PVs have a cast shadow on them from a neighbourhood tank (that ...
2
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0answers
65 views

How effective are "GreenUp" (opt-in utility company green energy) programs? [duplicate]

My local Seattle utility offers a "Green Up!" program where customers can pay extra on each bill to buy energy from more renewable sources. I'm signed up to contribute at the highest level ($12/month),...
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3answers
5k views

Why the world is using non renewable resources?

According to Wiki, A renewable resource is an organic natural resource which can replenish to overcome usage and consumption, either through biological reproduction or other naturally recurring ...