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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1answer
38 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
21 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, ...
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2answers
57 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 ...
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1answer
61 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
39 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 ...
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2answers
120 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
71 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
81 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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1answer
138 views

Where can I get a methanol generator?

I’m looking for a source for a methanol generator. Google is not helping. If nobody makes them, maybe a good solid methanol motor could be attached to a generator. Please help me if you have ...
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2answers
41 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....
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2answers
112 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 ...
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1answer
100 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
153 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 ...
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1answer
87 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 ...
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2answers
46 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
276 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 ...
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1answer
352 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 ...
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3answers
66 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
176 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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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
67 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
325 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
137 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
103 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 ...
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1answer
101 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
126 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
151 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 ...
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1answer
33 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
66 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 ...
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1answer
466 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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26 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 ...
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1answer
102 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
3k 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 ...
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147 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
104 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 ...
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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
231 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
157 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 ...
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1answer
131 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,...
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1answer
102 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
77 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 ...
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0answers
64 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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1answer
243 views

What software should I use to design and simulate a solar-assisted cooling system? [closed]

I will be developing a solar-assisted absorption cooling system similar to the one described in the image attached. What software could I use to design and simulate a thermal system like the one ...
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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 ...
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1answer
70 views

Is there an “energy returned on materials invested” index for energy sources?

We already try to measure how much energy is invested (EROEI) in the production of energy, but I have a hard time finding numbers on the materials invested. For example: What is the total energy a ...
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1answer
289 views

Transmit solar over multiple time-zones?

I heard that at big voltages (10 000+V) the energy loss along a wire is very small. Unfortunately I've got little electrical knowledge, but this sparked up a question: Considering that peak ...
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2answers
239 views

Can The UK Be Powered Practically By 100% Renewables?

Taking into consideration the landmass of the whole of the United Kingdom, areas of open country where windfarms could be placed, areas of country designated as wildlife havens and also areas of ...