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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 ...


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%


38

Yes, but it's a small fraction of what they produce. Wind turbines need measures to deal with cold and ice. Heating is one of them. Canada address the problem in Wind Energy in Cold Climates. Based on actual measurements, icing can occur up to 20% of the time between the months of November and April. Wind turbines must therefore be able to sustain at least ...


36

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

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

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) ...


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 ...


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 ...


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

I would agree that on its face this seems sketchy, but there's a fairly simple way of debunking this. (Strictly back-of-the-envelope calculations.) The neutrino flux experienced on any given part of Earth's surface is approximately 3 * 10^15 per square meter per second, or 10^19 per hour. The average solar neutrino carries an energy of ~400 keV. 1 kwH = 2....


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 ...


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

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

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 ...


9

Summary: The data (model + coefficients together with source citations) of the Lean ICT study are available (see below). HD Video streaming consuming between 250 W and 1 kW power equivalent is plausible compared to a study from 2012 finding 780 W. The Stiftung Warentest formulation cited by OP is IMHO misleading: it does not mention the crucial fact that ...


8

No, that claim is highly inaccurate. I'm guessing that it's somehow related to the part of a talk that was widely quoted (also by mainstream media): Shai Agassi, the founder and former CEO of Better Place, also touted the importance of the rate of battery innovation during his talk at the Cleantech Investor Summit. He said the energy density of ...


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 ...


8

The original research that produced this was done in a collaboration between the University of Glasgow and the University of Oslo, and UoG details it here. While the Glasgow part is available here, the part we are interested in is available here, but is $30. From the summary, it looks like the comparison is between the cost to produce the plastic used in ...


8

There are multiple different break-even prices that people usually quote. The fiscal break-even is the oil price at which the fiscal balance is zero. The external break-even is the oil price at which the current account balance is zero. Both prices can be very different from what it costs Saudi Arabia to pump oil from the ground. A good dicussion of the ...


7

The original video and forum post does a much better job explaining what is going on and states that the four (4) tea light candles are being used to warm the smaller inner flower pot which has the top drain hole blocked off while the large outer flower pot is used to create a convection effect that draws air past the warm inner pot and out the top. The ...


7

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 ...


7

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 somewhere in the middle of the range stated by Reuters, depending on the exchange rate of the day. The OpenEI configurable chart trends lower, but only outliers lie ...


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