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 ...
  • 18.9k
33 votes
Accepted

Does a human on a bicycle travel more efficiently than any other species?

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 ...
  • 99.4k
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 ...
  • 1,395
20 votes

Do "smart meters" bring about any significant savings?

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 ...
  • 134k
14 votes
Accepted

Are claims about saving power by turning appliances off instead of leaving them in standby accurate?

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 ...
  • 5,506
13 votes

Does a mobile phone charger that is plugged in but has no phone attached to it use energy?

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. ...
  • 232
12 votes
Accepted

Does Leonardo DiCaprio fly on private jets?

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 ...
  • 1,093
11 votes
Accepted

Does a deep freezer use more energy when there is a layer of ice in it?

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. Frost formation ...
  • 78.1k
9 votes
Accepted

Does streaming a video to smartphone consume 1000W of electricity?

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 ...
9 votes
Accepted

Do setback thermostats cause more energy to be used, and does the heating type matter?

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 ...
  • 4,668
9 votes
Accepted

Does Shell's "Nitrogen enriched" gas have positive effects?

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 ...
  • 99.4k
8 votes

Did Volkswagen, Chrysler and/or GM cut diesel tailpipe emissions by ~99% over a decade?

No they haven't, nor have they claimed so. Precis 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 ...
5 votes

Can Hemp free us from oil dependency?

"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 ...
  • 2,374
5 votes

Any scientific evidence that bubble wrap on windows lowers energy bills?

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 ...
  • 15.8k
5 votes

Is DAB+ digital radio more energy efficient than FM radio?

[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-...
4 votes
Accepted

Do "smart meters" bring about any significant savings?

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 ...
  • 9,436
3 votes

Do calcified water heaters use more energy?

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 ...
2 votes

Can the US be powered by a 100 miles x 100 miles solar grid?

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 ...
  • 380
2 votes

Do setback thermostats cause more energy to be used, and does the heating type matter?

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, ...
  • 99.4k

Only top scored, non community-wiki answers of a minimum length are eligible