Skeptics Stack Exchange
Skeptics Stack Exchange

Questions tagged [energy-efficiency]

for questions about claims based on energy efficiency.

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

Obviously, I am talking about simple charger without any indicator lights etc. If yes, why does it use energy when the circuit is not closed? Examples of the…
Dan
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Can the US be powered by a 100 miles x 100 miles solar grid?

In this article Elon Musk is quoted to say that the US can be powered by a solar grid shaped as a square (in video he says "a corner of Utah or Nevada") 100 miles x 100 miles big. “If you wanted to power the entire United States with solar panels,…
Paul Smith
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Does a human on a bicycle travel more efficiently than any other species?

Steve Jobs claimed on video that a bicycling human is more efficient at locomotion than any other species can manage. He repeated it separately on video, and in writing. The quote is still oft repeated. A poster print run raised 5k USD on…
Anko - inactive in protest
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Do Starship's grocery delivering robots consume only as much energy as boiling water for a cup of tea per trip?

Starship Technologies is a robotics company with a program of developing robots that will deliver takeaway meals etc. using small robots such is this: One particular press release on their website makes this claim: Starship’s robots are powered by…
Weather Vane
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Does the phase-out of incandescent light bulbs measurably reduce overall electrical power consumption?

Many countries are phasing out incandescent light bulbs. For example, in the European Union, various types of classic light bulbs have been removed from the market in the last years. The claim is that this process will help reduce overall electrical…
Heinzi
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Do setback thermostats cause more energy to be used, and does the heating type matter?

It was first brought to my attention by a local HVAC Contracting company, that a programmable/setback thermostat would actually cause my home heating system to use more energy, and hence for me to have higher heating bills. Their explanation was…
cobaltduck
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Does driving a car in a lorry's slipstream increase fuel economy?

On UK roads, I frequently see cars driving very closely behind larger vehicles, attempting to stay in their slipstream, reduce drag and thus increase fuel efficiency. Given the dangers of driving so close, are there any studies which demonstrate…
Mark Booth
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Are Hummers more environmentally friendly than Prius?

I've heard this rumor a few times (example). The argument is that it takes energy to make the car, and when you take into account how long each car will last on the road, driving Prius's over a large number of miles will end up requiring more…
BlueRaja - Danny Pflughoeft
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Do "smart meters" bring about any significant savings?

UK television stations are showing multiple commercials such as this one which make claims about making significant savings if you get a smart meter (the linked ad claims fitting a smart meter would save enough money to run a mobility scooter for…
GordonM
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Are claims about saving power by turning appliances off instead of leaving them in standby accurate?

I keep hearing this argument that if you powered down all the appliances you normally leave on standby (TV, hifi, set top box, DVD/Blu ray player, computer, etc) you'll save nearly £90 a year in electricity bills. However, the table in the linked…
GordonM
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Does streaming a video to smartphone consume 1000W of electricity?

The German test magazine "Stiftung Warentest" tested video streaming platforms in the magazine 1/2020. As a side note they write on page 35: Laut Studien der grünen französischen Denkfabrik "The Shift Project" erzeugt Videostreaming enorme…
yankee
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Are ion heaters significantly more efficient then normal electric heaters?

An ion heater manufacturer claims their ion heaters are a lot more efficient than common electric heaters: How ion boilers (heaters) STAFOR can reach COP 1,57? In solid conductors only half (statistically) of the free electrons react to the…
Suma
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Does a deep freezer use more energy when there is a layer of ice in it?

In light of the potential upcoming power shortages in Belgium, there are a lot of "tips" going around to save power during the cold months. One of them is to thaw out the ice in the deep freezer as, according to one of the power companies, a layer…
ratchet freak
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Are insulating window films worth it?

I'm curious if tests have been conducted to evaluate the energy efficiency gains and resultant savings produced by insulating window films like these 3M Window Insulator Kits. (There are also films that are adhered directly to window glass that…
Hendy
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Are electric stoves less energy-efficient than gas stoves?

According to an article on howstuffworks.com and several other online sources, electric stoves are generally less energy-efficient than gas stoves, since it requires "about three times as much energy" to produce and deliver electricity to a…
Anderson Green
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