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 ...
The quoted statement says "energy to move a kilometer".
On an "energy to move a kilometer" basis, the statement is definitely false.
Acccording to Dr. Karen Oberhauser, a tagged monarch butterfly has been confirmed to travel 265 miles in one day.
According to How Much Fuel Do Monarchs Burn? reporting Dr. David Gibo's research:
On 140 milligrams of ...
A very simplistic calculation shows that the initial energy input is quickly paid back. The cited numbers show a manufacturing energy difference of 1.8 - .11 = 1.69 kW-hr = 1690 W-hrs. A CFL with a light output equivalent to a 75 W incandescent bulb typically uses about 20 W, or about 50 W less than the incandescent. 1690 w-hrs divided by 50 watts = 34 hours....
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) ...
There have been a number of studies that investigate how consumer behaviour changes when feedback from a smart meter allows them to understand their usage habits.
2010, The impact of informational feedback on energy consumption—A survey of the experimental evidence
This paper looked at the effect of In Home Displays (IHD) from a dozen pilot programs in ...
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 ...
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 ...
This question reminded me of the xkcd what-if post which mentions that "If an unused charger isn’t warm to the touch, it’s using less than a penny of electricity a day", but without references. Searching more I found the reddit thread following the xkcd post, which has lots of links, including to pages 68 and on of the free (Creative Commons) book "...
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. 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. ....
In general, frosting has generally a negative effect on cooling. How much depends on the air flow in the freezer, as cold air has to reach every part of the contents easily.
Water vapour deposited from the air leads to frost
formation and has a great influence on heat transfer with
the following positive factors.
TLDR: No, it is not more than 100 % efficient, the test performed was probably invalidated by using a heat meter assuming water as a heat transfer fluid, while propylene glycol/water mixture was actually used.
Some details about how test was performed can be found on a Czech reseller site:
Ion boiler STAFOR 3-5
Circulation pump Vilo 25/7
Here are the findings from a study from the Canada Mortgage and Housing Corporation (CMHC pdf)
They used a twin-house setup: two identical houses with different settings for the heating.
The winter experiments demonstrated that as the setback
temperature is decreased, energy savings increase. Higher
savings are achieved (as a ...
A good starting point for information about this topic is The Gasoline Wars Chemical & Engineering News, vol. 87, pages 20-21.
First, when shell says "nitrogen-enriched", it does not mean that nitrogen itself (such as dinitrogen in air) is added to the gasoline. Instead, it means that an amine detergent compound is added to the gasoline.
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 ...
No, it's not true.
According to this article in Scientific American, there is a slight additional energy required to start up a fluorescent bulb, but it lasts an extremely brief time:
that power surge is so brief that its energy draw doesn't amount to much: the equivalent of a few seconds or so of normal operation, according to U.S. Department of ...
No they haven't, nor have they claimed so.
The journalist or editor didn't do their job correctly and made a mistake. The figure refers to particulates, not to other important emissions and not to all emissions.
As others have noted, important tailpipe emissions include gases like CO2 which manufacturers quote figures for ...
It depends on the renewable energy technology, but the answer is generally a few years.
Here is a detailed analysis of the embodied energy in two sizes of large scale wind turbines (850 Kw and 3 MW). This study involved a very detailed assessment of the embodied energy, which showed that previous estimates were considerably low. In spite of this more ...
"In 2015, the United States consumed a total of 7.08 billion barrels of petroleum products" https://www.eia.gov/tools/faqs/faq.cfm?id=33&t=6
One US oil barrel is 159 litres. One acre or rapeseed gives 600 litres oil ( https://spa.merinfo.se/question/hur-manga-liter-olja-far-man-pa-ett-hektar-raps ) (I assume hemp is in the same ballpark). That gives 3....
The article you found on ecorenovator did some crude tests with a thermometer. He found it makes a significant difference on single-thickness glass, but not on double-glazed windows. The tests look reasonable, and would line up with the theory about trapping a layer of air. So I'd say yes.
The original tests seem to be documented here, but its a bit unclear....
[Edited to add reference to European Broadcasting Union Cost-Benefit analysis]
A cost-benefit analysis of FM vs DAB undertaken for the European Broadcasting Union based on a detailed analysis of Big-5 EU countries estimated the OpEx requirements for FM and DAB radio transmission (basically power consumption + facilties costs).
DAB had greater energy and ...
Oddthinkings answer is excellent though I'd like to take a slightly different tack to the question.
With some smart meters your bill can change quite dramatically depending on the design of the smart meter.
Research paper: Static Energy Meter Errors Caused by Conducted
Smart energy meters giving readings up to six ...
Calcification's effect on water heater efficiency depends on the design of the water heater and the type of calcification. The question referred specifically to electric water heaters, however, some of the links were referring to gas water heaters. In a gas water heater, the burner is usually located under and outside of the tank and heats a heat exchanger ...
In the comments to your question, you ask for percentages.
The total electricity production for Europe is approximately 3,200 TWh:
Electricity production and supply statistics
CIA World Fact Book
The savings alleged in the OP are "close to 40 TWh": which is approximately 1% of the total.
The first link above claims to be able to measure small percentage ...
I'm skeptical, since if it true, then why didn't anyone build this square already?
Just focusing on this part. The other answers already seem to indicate that such an area might be large enough to produce electricity in the order of what is needed. Now this doesn't mean, it's economically beneficial to do that.
You can only expect people to actually ...
According to The Effects of Thermostat Setting on Seasonal Energy
Consumption at the CCHT Research Facility (2005):
An 18°C night and daytime setback reduced the length of time the furnace ran, resulting in furnace
electrical savings of up to 6.4% and furnace gas consumption savings of up to 17% on the coldest day. A
16°C night and daytime setback ...
Yes, by simple physics, it will save the customer some electricity.
The rate at which heat is lost by a hot water tank is proportional to the difference between water temperature and air temperature. And it's also proportional to the U-value of the covering. Adding insulation will decrease the U-value, and so will decrease the rate at which heat is lost.