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Hot answers tagged

84

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 required to power Germany, Europe, and the whole world, respectively, as estimated by the German Aerospace Center (DLR). That estimate puts 100x100 miles for ...


52

It is indeed a fact, based on the documents released by the FOIA, that both FBI and OSS (the precursor to CIA - CIA didn't exist at that time) obtained papers from Nikola Tesla after his death in 1943. Some of the released material show that the Department of Defense (DoD), among others, was interested in these papers because: "SUBJECT: Papers recovered ...


38

Yes. They refer to International Energy Agency's 2016 Key Renewable Trends report, which contains these 2 graphs: Combining these two graphs shows that Wind energy is 3.3% of the 13.8% of the renewable fuel share. 13.8% * 3.3% = 0.46%


35

Summary: yes, the area shown is reasonable, as a visualisation of the surface area of panels required to generate electricity equal to total US electricity consumption, on a multi-year average: that area of panels would generate 500 GW, which is above the current US annual average electricity consumption of 425 GW Calculations below are taken from this ...


35

I decided to communicate directly with the town itself. The response to my email is reproduced below: Please read the interview with Mayor Manuel on (witn.com). Also, there will be a message from the Mayor on our website (townofwoodlandnc.com) by this afternoon. During our Board meetings public comments are always welcomed and we listen to anything a ...


30

And the mechanical friction caused by the alternator does not depend on whether electricity is being needed or not. Correct. In other words, when energy is not needed it is wasted Wrong. The electrical energy produced by the alternator is not the result of mechanical friction but of magnetic force on top of the (very small amount of) friction, which ...


30

The origin of this claim is Andrew Walden's 2010 article Wind Energy's Ghosts. He is specifically referring to the wind turbines installed in California between 1981 and 1986 in three locations: Altamont, Tehachapi, and San Gorgonio. The article says 15,000 wind turbines were installed there in this time period. An American Wind Energy Association report ...


29

NO, (or YES dependent on the definition of primary energy) as answer to the claim: "Wind power does not account for less than half a percent of total global energy usage in 2014." The wording of the report (from Jordys answer)indicates that they compared electrical output of renewables to the energy contents of combustibles. Putting these on the same graph ...


28

No. A typical home panel might consume the electricity released from about 1/2 a ton of coal. (Update: Or 1/6 a ton of coal, if you use combustion energy rather than electrical generation.) According to The Energy Balance of the Photovoltaic (PV) Industry: Is the PV industry a net electricity producer?, the Cumulative Energy Demand for photovoltaic cells ...


25

TL;DR; Tesla's Patents and notebooks are available. Tesla was often interviewed and gave public demonstrations. There's no convincing evidence that he had really discovered a means of transmitting power that could be commercially implemented in the way he envisaged in his "World System". There's no evidence (that I can find) which proves his system could ...


25

The New Scientist calculated the number of deaths per kilowatt-hour question based on the data from International Atomic Energy Agency in 2011. According to the New Scientist: The agency examined the life cycle of each fuel from extraction to post-use and included deaths from accidents as well as long-term exposure to emissions or radiation. They ...


25

Mathematically accurate From Cornell University News: An acre of U.S. corn yields about 7,110 pounds of corn for processing into 328 gallons of ethanol. That's 3,225 kg and 1241 liters. Let's assume that the "large SUV" has a twenty gallon (76 litre) tank. So that's 7110 pounds divided by about 16. That comes out to 433 pounds (196 kg) of corn. ...


23

Wikipedia explains: There is a scientific consensus that perpetual motion in an isolated system violates either the first law of thermodynamics, the second law of thermodynamics, or both. There is a long history of different types of failed perpetual motion machines - enough for books to be written. Kevin Kilty has written a more readable discussion ...


23

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 calculations here shows that 10,000 square km of solar panels could provide more energy than the US uses. This was in response to the same (or at least a similar) ...


20

Do wind turbines kill many birds each year? In short: An upper estimate might be of the order of half a million birds per year in the USA. However it seems that hundreds of millions of birds are killed by collisions with other man-made structures. So wind turbines account for a small percentage of bird deaths attributable to human activity. Nevertheless ...


19

TL:DR; Yes, the UK has potential wind resource to power itself many many times over. Yes, it could be five times as much (range: 4-200x). No, its technical potential harnessable wind resource is not 2000 TWh a year - it's much larger, but we don't know how much more; it's probably in the range 10,000 - 80,000 TWh/y. For context, UK primary energy demand is ...


16

Wind turbines are perfectly safe for Humans. You your self brought two credible sources. And there is this article by Simon Chapman is professor of public health at the University of Sydney. He has no financial associations with any wind energy company. who references the British Acoustics Bulletin: The British Acoustics Bulletin has just published ...


15

It cannot be done safely, or with more than limited success. Your results may vary. First, we need to understand how batteries work. Two chemicals with opposite charges are separated in a cell. When a circuit is completed from the cathode (+) to the anode (-), electromagnetism happens and the two chemicals react with each other, releasing electricity, until ...


14

I'll try my shot at giving a good referenced answer. The claim As evidenced in this clearer explanation of the claim, by efficiency it is meant that the heat of the candles is retained by the pots and released slowly. There is also a secondary claim that this makes the system efficient enough to heat an open space. There is no claim that the total energy ...


14

Answer: Yes, you can save that much. £90 really isn't that much over the course of a year - about 25 pence per day. According to this website The price of electricity in the UK in 2013 averages 17.2 pence per kWh That means over the course of one day, you need to save 1.45 kWh (kilowatt hours) in order to save 25 pence. You can accomplish that by ...


13

The question cites two links, but neither of them raise as a claim the question of how long it takes for a renewable energy system to recoup its energy cost, which is the title of the question. First I'll address the very broad question in the title, for which no notable claim was cited (but which will exist somewhere out there). The two links cited raise ...


13

The simple answer is yes. The more complex answer is that the number of deaths is nothing in comparison to other man made structures and the risks from climate change. There have been several studies done to find the environmental impact of wind farms on birds. Generally birds lack the ability to dodge humans and their quest for global supremacy. From the ...


12

Probably not. Air infiltration in houses is measured by a "blower test" in which a fan is installed in a door, and used to draw air out of the house. Here is a discussion and video of air inleakage through a gasketed switchplate during a blower test in a home. The artcle is on EnergyVanguard.com, which is a site and organization focused on energy ...


12

No, lithium scarcity is not a barrier to the take-up of electric vehicles. From Bloomberg: The world’s largest untapped lithium reserve -- containing enough of the lightest metal to make batteries for more than 4.8 billion electric cars ... according to the U.S. Geological Survey.


12

Yes, he has flown on a private jet on at least a few occasions. From the WikiPedia on Leonardo DiCaprio: ... his use of private jets and superyachts has attracted criticism by some sections of the media.[148][149][150] In 2016, during a vacation in Cannes, France, he made a one-day visit to New York City by private jet to collect an environmental award. ....


11

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 involved in e-Plant, a Dutch company which already has similar product on the market have published a number of scientific papers in Biotechnology for Biofuels ...


10

This question can be answered using a Life Cycle Analysis, which looks at emissions over the total life cycle of a product - including manufacture, use, and disposal. Many such studies have been performed, here are two examples: A 2012 UCLA study for the California Air Resources Board, and A 2015 study by The Union of Concerned Scientists Both of these ...


8

This is going to be something of a sideways answer. I'm going to explain why it's possible to find a "yes" and a "no" to the question, and for them both to be justifiable, and both to be supported by good references! There is no single unique calculation of total greenhouse gases emitted. One has to specify a particular boundary for the calculation; and the ...


8

Zinc-Carbon and Alkaline batteries are different battery types. The have a similar voltage and come packaged identically, however the amount of stored energy varies greatly. Comparison of battery types As you can see, alkaline batteries, such as Duracell, can store up to 5 times more energy in the same volume. However, alkaline batteries also have a ...


8

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 of the users of Quora are: The obvious problem with Mills theory is Hydrinos don't exist. It's 99.99999% chances to be a scam. [...] What we are looking at ...


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