231
votes
Accepted
Do wind turbines consume more energy than they produce in a lifetime?
The Guardian cites a 2010 study that found:
the average windfarm [sic] produces 20-25 times more energy during its operational life than was used to construct and install its turbines. It also ...
tim♦
- 51.8k
223
votes
Do solar panels create 300 times more toxic waste per unit of energy than nuclear-power plants?
This study, by a nuclear advocacy group, is based on treating a cubic meter of used solar panels as being equivalent to a cubic meter of spent uranium.
Just digging around the links, I find the ...
- 3,647
91
votes
Accepted
Have 1.5% of all nuclear reactors ever built melted down?
The number claim is correct in the context of nuclear power stations.
The "440" reactors from the claim indicate, that we are talking about nuclear reactors for power generation in power ...
- 1,960
85
votes
Can fracking help reduce CO2?
If it replaces coal mining for power production, fracking reduces CO2 emissions, but that's not the whole story. Burning anything results in increased CO2 emissions, and methane leaks in fracked gas ...
- 9,911
84
votes
Accepted
Can the US be powered by a 100 miles x 100 miles solar grid?
Can the US be powered by a 100 x 100 miles solar grid?
Desertec is basically the same idea, solar plants located in North Africa supplying power to Europe. The article includes a map showing the area ...
- 19k
67
votes
Did wind and solar exceed expected power delivery during Winter Storm Uri?
Wind production exceeded all forecast metrics, solar production exceeded short-term forecasts but not operational forecasts.
TL;DR: On 2/15 both solar and wind exceeded the short term forecasts which ...
- 9,911
53
votes
During Great Britain's coal-free day, were coal plants shut off, or active and generating power GB didn't use?
Quick Take: There doesn't appear to be available information to determine if the coal plants were burning coal, although not contributing electricity to the grid; there is sufficient information to ...
- 859
52
votes
Accepted
Can Genesys' solar amplifier generate 40kW of power from a 200W solar panel?
Red flags:
As Kevin points out, 20kW from a 200W panel is PFM (Pure Frelling Magic).
Significant portions of the press release are dedicated to how strong the patent is. No patent number is given.
...
- 1,068
49
votes
Accepted
At the current rate are we going run out of fossil fuels by 2060?
No
First, this figure is for petroleum. For coal, the figure is much larger. Some of the figures I found for coal were 133 years, "anywhere from 68 years to a hundreds of years", and 357 ...
- 2,873
30
votes
Can fracking help reduce CO2?
First, let's agree on definitions. Fracking (or hydraulic fracturing) is a process by which fluids are drawn from the ground. In this context, the fluid would either be oil or natural gas.
From ...
- 10.2k
26
votes
Have 1.5% of all nuclear reactors ever built melted down?
In 2012, there were 437 nuclear reactors. From the World Nuclear Association:
Over 115 commercial power reactors, 48 experimental or prototype reactors, over 250 research reactors and several fuel ...
- 14.1k
23
votes
Can the US be powered by a 100 miles x 100 miles solar grid?
It seems possible, at least in theory. Of course, whether it possible and whether it's remotely economically feasible are completely different questions.
A decent back-of-the-envelope series of ...
- 1,405
22
votes
Can Genesys' solar amplifier generate 40kW of power from a 200W solar panel?
One red flag that's pretty clear in the diagram on the site is the hydrogen storage aspect.
A 200 watt solar panel isn't going to power an entire home all day. Adding a device to split the water into ...
- 385
20
votes
Do wind turbines consume more energy than they produce in a lifetime?
Given there's much talk about the 2010 study, here's a 2013 one. It mainly expand the other one, by:
"Tweaking the lifetime": very low ones were assumed for conventional plants (also including ...
- 332
19
votes
Do solar panels create 300 times more toxic waste per unit of energy than nuclear-power plants?
No. Nuclear energy produces far more toxic waste than solar.
Distribution of the fake news story
The fake news that began circulating at the end of June 2017 stems from a self-described "study" ...
- 291
15
votes
At the current rate are we going run out of fossil fuels by 2060?
For oil, using proven reserves and current oil production, the date is more like 2067. World proven reserves are approximately 1.7 trillion barrels, or 1.7 million-million barrels (EIA figures]). ...
- 2,443
13
votes
Did wind and solar exceed expected power delivery during Winter Storm Uri?
Technically yes, but not in the way you may think.
Here's the data for all electricity generation in the ERCOT grid:
The cold front started coming in on the night of the 8th and you can see how wind ...
- 894
13
votes
Did wind and solar exceed expected power delivery during Winter Storm Uri?
Yes, according to data from the Electric Reliability Council of Texas (ERCOT), wind sources greatly exceeded their forecasted production for Monday, while solar sources slightly exceeded their ...
- 11.4k
11
votes
Accepted
Can one generate enough electricity from a plant to power a cellphone?
Not impossible, but highly unlikely
The technology described does exist. Scientifically this is called Plant Microbial Fuel Cell. However Bioo's claims of 40 W/m² seem greatly exaggerated.
People ...
- 26.6k
11
votes
Can Genesys' solar amplifier generate 40kW of power from a 200W solar panel?
40kW out of a 200 Wp solar panel?
200 Wp (Watt-peak) is the nominal power of the solar panel.
It means that the solar panel produces 200W of power when the module has a temperature of 25°C and is ...
- 488
10
votes
Is solar power the cheapest form for utility companies to build?
Its true - FOR NEW PROJECTS
Costs of power are complex, lots of factors muddling things. Even things like the rising cost of insurance for coal power factors in.
A reasonable argument can be made ...
- 503
8
votes
Has Brilliant Light Power developed a new source of energy from water molecules?
No, the claims are completely untrue. The science of why is a little complicated.
The opinions of the users of Physics.SE are that it is:
improbable to the point of being gibberish.
The opinions ...
- 197
8
votes
Is over-reliance on wind energy the real reason PG&E is cutting power?
Unsurprisingly, given that it is from the Heartland Institute, it appears to be wrong. Looking at 2018 government data (note: Excel file), electricity generation in California is 30% greater in July (...
- 2,083
7
votes
Is the production of nuclear power very expensive?
The figures seem consistent with most sources:
A Lazard 2018 study puts nuclear firmly in that range.
A UK government study puts new nuclear construction at 95 GBP per megawatt hour, which sits ...
- 2,949
7
votes
At the current rate are we going run out of fossil fuels by 2060?
On current trends, we won't run out of fossil fuels, even oil or gas.
This is a slightly misleading statement because the question asks about the current burn rate, and this answer rephrases to "...
- 187
6
votes
Do wind turbines consume more energy than they produce in a lifetime?
The roi depends on the windmill, and it could be bigger than 3-6 months.
For example, if the windmill operates in colder regions, "the additional cost of such a system [de-icing] can be compensated by ...
- 89
6
votes
Does the average carbon footprint per bitcoin transaction range from 233.4 to 363.5 kg of CO2?
I'll note that the "Power consumption [MW]" section of the linked paper cites a bunch of other papers, some of which do provide the carbon footprint of individual bitcoin transactions. For ...
- 930
6
votes
Accepted
Would covering 10% of hydro-power reservoirs with solar panels generate as much power as fossil-fuel plants worldwide?
Technically possible. Do note, though, that getting a solar cell to produce its nameplate capacity is much harder than doing the same with a fossil fuel generator.
The specific claim ("nearly 4,...
- 1,588
5
votes
Does Africa have to choose between renewable energy and economic growth?
An answer to this question depends how one chooses to interpret that Putin said. I interpret it as him saying solar panels are more expensive than alternatives, perhaps for the next 20-30 years.
That ...
- 59.6k
Only top scored, non community-wiki answers of a minimum length are eligible