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Questions tagged [energy-efficiency]

The percentage ratio of energy produced to energy supplied to a system; or a measure of minimum energy required relative to energy actually consumed; or a measure of relative energy consumed to provide the same energy service.

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3answers
1k views

How to cover an open-top shower, to make it feel warmer while showering

There is a product on the local market in New Zealand called "Showerdome" that is a clear plastic dome that can be attached over the top of most open top showers. Covering the top of a shower reduces ...
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1answer
234 views

Energy saving lamps suggestion

My dining room lights are shown in the pictures. I have two of those fixtures, with 3 bulbs each. 1) On the plastic chandelier it says "MAX 40W", but the lamps that when I first arrived in the flat ...
4
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2answers
694 views

How much energy costs do portable solar panels save in a house?

Our Houston area HOA does not allow roof top solar panels and I doubt they would survive our hurricanes too. I discovered NRG Energy sells these portable solar panels under their goal zero brand. If ...
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2answers
256 views

Less energy consumption when we stop using fossil fuels?

What's the best way to find out how much less energy we would use if we would quit fossil fuel usage altogether? What would be the percentage entailed? I know it's easy to find out with electrical ...
11
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3answers
751 views

Use waste heat of electrical appliances in place of traditional heating?

Does it make sense to keep electrical appliances turned on, or at least not turned off, during the winter as a partial replacement for traditional heating? I'm thinking in particular of computers, ...
11
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1answer
1k views

Do switchable sockets left “on” use electricity if there's nothing plugged in?

My flat is fitted with switchable sockets as per below: Please settle an argument a friend and I are having: if a socket is switched "on", is it wasting electricity if nothing is actually plugged ...
7
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5answers
339 views

Practical and cheap ways to get warm at home this winter?

Since winter is near, can someone suggest some practical ways to get warm at home without spending too much in gas or electricity? Also for every solution, please add if it can be done homemade and ...
7
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1answer
119 views

Have spray-on solar cells hit the market yet? What other lightweight cell can I use for unusual shapes?

I read in a couple of places that researchers at Sheffield University have made spray-on perovskite cells at efficiencies of 11%. I was interested in this because it is lightweight and could fit more ...
8
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1answer
2k views

Does repeatedly turning on and off an appliance tend to damage it?

When nobody is watching the TV, my practice is to turn it off, so as to save electricity, even if I know that someone will want to watch it in the next 10 minutes. However, it is claimed that turning ...
8
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1answer
175 views

Is the energy used to manufacture and install solar panels in proper balance with the energy output from them? [duplicate]

From mining/harvesting materials to altering them into useful manufacturing materials to making actual products, and then packaging them and shipping them to retail stores, or directly to customers, ...
9
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6answers
395 views

How can I use my own body as an energy source for greater environmental sustainability?

I've had the epiphany that my body is a living vessel of energy production (and consumption), just like all other energy sources and associated forms of consumption or re-allocation around me. My ...
8
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1answer
140 views

What would be the most sustainable biomass source for (100%) ethanol production?

So I have read that sugar (cane) is way more efficient than corn, (and that Brazil leads the way in taking initiative to actually bother with this advance in biofuels sustainability), and that, based ...
12
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5answers
382 views

Lowering the heating thermostat at night: is it really worth it?

I've heard some very conflicting information regarding the effect of lowering the house heating thermostat at night. On one hand there are academic papers (such as Thermostat strategies impact on ...
11
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1answer
117 views

What are the sustainability issues in moving house?

We are moving house from one side of the UK to the other. The financial costs of doing so have raised the facetious question would it not be cheaper to sell everything here and buy it again, there? ...
9
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1answer
125 views

Does it matter where I charge my device?

I have a number of small devices that can be charged in my car (using a charger that plugs into the car's electrical system and is powered by the car's gasoline engine) or my home (using electricity ...
6
votes
1answer
163 views

MVHR no longer the ventilation of choice in some Nordic countries?

We've covered Mechanical Ventilation with Heat Recovery (MVHR) before here, and it's been the ventilation method of choice for Passivhaus buildings for many years. But I heard something interesting ...
4
votes
1answer
303 views

Which one is more sustainable: central A/C or window A/C?

I would like to know which kind of cooling will be the most sustainable, that is, will use the least energy and cooling agents. I am considering summers with temperatures in the high 90's (35-37 ...
5
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2answers
569 views

What is investment/outcome ratio for wind energy in terms of energy (EROEI)?

Merchants say that I can have 1 watt of energy per every $1.5 invested. Yet, I have heard from people "from the business" that the installation alone (forget mining the ores and smelting the parts) ...
7
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2answers
195 views

Which is more “meter” efficient? I would like my utility bill to significantly cheaper

I live in a 3 bedroom, two bath, large den, kitchen, attached garage Patio home. I live alone except for when my kids are in from college which is rare. I am hot natured so I keep my electric heating ...
6
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2answers
3k views

How much power does an Electric Airpot use while on standby?

We have just brought a Buffalo K711 4.25L Electric Airpot that is great for my wife as she is disabled and can find a kettle hard to pour. I was expecting it to be well insulated, however its sides ...
12
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3answers
216 views

Options to suggest to landlord for cost savings via renewable energy?

I have a landlord who is very interested in saving money. I wanted to suggest options to her to help her save money while reducing environmental footsteps. However she is not motivated to save the ...
10
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2answers
362 views

Should I take advantage of the higher heat pump COP during the warmest part of the day and “bank” heat in the house?

I am aware that heat pumps are able to move more heat into a building per unit of energy input (the "coefficient of performance" or COP) when the source (outside) temperature is higher. My question ...
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3answers
6k views

How can I estimate the gas usage of a pilot light?

Can anyone provide a method to estimate the gas flow rate to sustain a pilot light, using just the apparent size (flame width and length) and reasonable assumptions for things like gas line pressure? ...
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5answers
21k views

Is it practical to use an infrared space heater along with a heat pump system?

We live in a house that has a heat pump system, for AC and heat, with a second-stage heating coil for aux/emergency heat. It frequently gets down to below 30 degrees in our climate, at which point ...
9
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4answers
2k views

How to measure the energy output of a thermal solar hot water system?

I have a (thermal) solar hot water system with electric heating, and I'd like to be able to measure the amount of energy provided by just the solar heating. The system is set up like this: Water ...
3
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2answers
125 views

Photo voltaic windows Pro - Cons. Where to get them?

I intend to build a house in the near future and I want it done in a proper way. From my perspective "proper way" means also as much as self sustainable as possible. Hence I intend to generate/produce ...
9
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5answers
2k views

How can I measure the moisture content of my firewood to ensure good efficiency and clean burning?

It's clear that firewood that hasn't been well dried is more polluting and less energy efficient, hence the existence of various schemes to ensure firewood suppliers provide dry wood. Is there a way ...
9
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1answer
808 views

Olive oil versus sunflower oil

I wondered what was the best, in one hand for the health (but I guess the question should be asked somewhere else, shouldn't it?) and in the other hand for the earth. Which one, if there is one, is ...
8
votes
1answer
156 views

What can a smart thermostats and meters tell me about how to reduce my home energy consumption?

I'm considering a smart thermostat for my step-dad as a birthday gift. Here are some characteristics of the home: 3000 sq ft living with two people climate is arid with highs into the 100s (deg F) ...
22
votes
4answers
759 views

What form of electrical lighting has the smallest energy-footprint?

We all know that when it comes to household electrical lighting, LED lights consume the least amount of energy for a given amount of light, followed by fluorescent tubes, halogens, and Edison-age ...
15
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3answers
1k views

Shall I boil water with a water boiler (cooker) or with a pot?

I know that when making tea it uses less energy when heating the water when using a water boiler(cooker), than when using an electrical plate. A water boiler is directly heating the water, while a ...
5
votes
1answer
48 views

Which US university has done the most to reduce GHG?

Which US universities, either public or private, have programs that have shown quantitative reductions in GHG emitted? In fact I would like to see universities "bridge the gap" between themselves and ...
21
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4answers
133k views

Leaving the oven door open for heat - bad idea?

I've heard before that it's a bad idea to use an oven to heat your house, because it's inefficient and carries the risk of carbon monoxide poisoning. But what about leaving the oven door open after I'...
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3answers
2k views

What is the relationship between permaculture and sustainability?

What is the relationship between permaculture and sustainability? What are sound reasons why both urban and rural permaculture takes us further down the road to sustainability? Are there real-world ...
15
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2answers
3k views

Propane vs. Electric vs. Heat Pump

Is there a relatively reliable way to figure out what energy source to go with when upgrading appliances? We need a new hot water heater, for starters. Our current one is propane. Options include ...
13
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6answers
3k views

What is the relationship between energy efficiency and sustainability?

What are the sound reasons (let's put aside the unsound reasons) why increasing energy efficiency takes us further down the road to sustainability? Are there real-world circumstances whereby ...