the sustainable use of energy, through efficiency and renewables. Use this tag for questions on energy in general. For questions on a specific energy type see [electricity] or [heating]. For questions specificially about efficiency use [energy-efficiency]

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1answer
50 views

What is the number 1 country by global installed wind capacity: the United States or China?

In the following graph: We see that China surpassed every single country in wind energy production, except the United States. But these statistics are up to 2009 only. So my question is: what about ...
2
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4answers
442 views

What is the difference between “hydro” and “tidal/wave”? And what is the difference between “solar (heat)” and “solar panels”?

In the following graph: What is the difference between "hydro" and "tidal/wave"? And what is the difference between "solar (heat)" and "solar panels"?
4
votes
1answer
30 views

Sustainability of wood pellet sources for biomass boiler

We're considering a biomass boiler for our guesthouse (1820 vintage with corresponding energy issues). The opportunity to reduce gas usage and the economics of the RHI scheme in the UK (a sort-of ...
10
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1answer
123 views

Best way to dry hands

In our office toilets at work we have paper towels and a hand dryer. Is it better for the environment to use the towels or the dryer?
11
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1answer
113 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 ...
8
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7answers
193 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 ...
2
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0answers
26 views

What kind of population-to-agriculture relationship is the most sustainable? [closed]

City/Rural Relationship High concentration of humans and low concentration of agriculture that are largely fed by areas outside the city that are very low in human population but are very high in ...
9
votes
1answer
75 views

Is building vertically instead of horizontally in climate with large seasonal temperature changes more sustainable?

My main line of thinking would be that you would build tall skinny housing that would allow the heat to gather in the upper levels in the winter and the cooler air would gather in the basement/lowest ...
7
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2answers
156 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 ...
5
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1answer
65 views

Relative carbon footprint of gas or electric heating (UK)

Inspired by this question: Given the current UK (2014) generation mix, would changing a house from gas to electric heating increase or decrease its carbon footprint? The original question was about ...
11
votes
1answer
84 views

Reducing the setpoint by 1 degree C will save 7% energy: what's the origin of that claim?

I often hear a claim saying that reducing the thermostat's setpoint by one degree C will reduce the overall yearly energy consumption by 7%. I've heard heating control manufacturers, energy ...
5
votes
1answer
56 views

Synthetic Propane Manufacture

Methane (CH4) is available naturally. Propane (C3H8) is derived from Methane. Is there a process for synthesizing propane applicable to a micro-farm environment?
6
votes
1answer
115 views

How much wood can I burn sustainably, carbon neutral and in an ecologically responsible way from a forest?

While wood can - in theory - be a carbon neutral fuel, in practice burning wood creates a huge carbon debt and it may take a long time for all the carbon released by logging, soil degradation and so ...
6
votes
2answers
97 views

Is canned fish more sustainable than fresh?

I read this beauty-oriented article claiming that canned fish is more sustainable than fresh fish. Is this true? Listed below is a brief energy/sustainability brain dump on the subject. Canned fish: ...
9
votes
1answer
99 views

Is opening windows wide or opening them slightly more efficient for exchanging air in a room on a cold day?

For those who wish to replace the air in a room during a cold day with active heating: Given that the purpose of opening the windows is to exchange as much of the air in the room as possible with the ...
9
votes
4answers
115 views

Retrofitting insulation in a 4-storey home. Top down or bottom up?

I'm faced with the prospect of wanting to improve the insulation of a 4-storey Victorian (c1890) house in the UK that has solid stone walls and a top floor that is within the non-insulated roof space. ...
5
votes
3answers
88 views

Resources for Teaching Children About Solar Panels

I'm sure some of you will have already taken classes on Solar. The reason I am posting this question is to help out two Farmers in Kauai, Hawaii. They are currently creating an extension program ...
2
votes
2answers
244 views

Solar energy concentration using cylindrical Fresnel lenses

What are the advantages and disadvantages of using cylindrical Fresnel lenses as PV concentrators? My goal is to do some research and see which kind of Fresnel lenses are better to concentrate light ...
4
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2answers
107 views

Challenges of providing sustainable energy sources to meet future demand in Ireland

what are the main challenges Ireland faces as regards providing sustainable energy sources to meet future energy demand?
1
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2answers
176 views

Can an enclosed Pelton Turbine be used as a pump?

Can an enclosed Pelton Turbine be used as a pump, perhaps through the centrifugal forces created in a enclosed Pelton Turbine when it rotates at speed? The water striking out of the buckets of a ...
11
votes
3answers
7k views

Which type of portable electric heater is better?

When one is buying a portable electric heater, there are at least three different types available: Radiative halogen heaters Fan heaters Oil-filled radiators and similar Images of examples of each ...
6
votes
1answer
156 views

Should payback periods take the time value of money into account?

I am currently reviewing a paper estimating the payback period for different building renovation strategies. The calculations I see typically go something like this: you pay (say) USD 3000 today, ...
11
votes
3answers
326 views

Cost-effective alternative to rechargeable batteries?

Batteries are known to be the most unsustainable and expensive part of system exploiting renewable energy. So I am wondering, are there any alternatives to storing energy in batteries? Here I am ...
5
votes
2answers
306 views

Are power plants more efficient than typical gas-powered car?

For the last couple weeks, I've been hearing a lot of talk surrounding Tesla and "the electric car". What I'm curious of is whether or not it is more efficient to actually power an electric car (the ...
11
votes
4answers
184 views

Water heating / electricity production by using earth's warmth?

I'm very curious, why hasn't anyone done this? In most places on earth, the temperature gets 25 degrees higher (celsius) for every kilometer in depth. How hard would it be to drill 4-5km, put a ...
6
votes
1answer
300 views

Are tracking mounts cost-effective for home photovoltaic systems?

Solar PV panels are clearly more efficient at converting sunlight to electricity if they are mounted on racks that rotate to track the sun's apparent travel across the sky. However, tracking mounts ...
16
votes
1answer
708 views

Which solar power technology has the highest energy return on investment (EROI aka EROEI)?

Which solar-electric technology had the highest EROEI? Energy Returned On (Energy) Invested, also known as EROI and as EROEI, has become something of a fashionable metric *but see footnote. It is ...
6
votes
2answers
271 views

Want to build a portable solar refrigerator

I've got a 5v Peltier chip. What kind of and how many solar cells 4.5v 18mA do I need per 1 chip? I found these cells online on dealextreme, but there are also other different types. I'm lacking a ...
9
votes
2answers
529 views

How much energy does it take to create a single light bulb?

This question is a part of this question. Perhaps it is better suited on the physics SE, but here goes. I would like to know how much energy it takes, in the modern world, to construct an ordinary, ...
13
votes
2answers
311 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 ...
12
votes
2answers
325 views

Tea in the microwave

I occasionally need exactly a cup of water boiled for tea. Whenever I boil the kettle to do so, I wonder if it would be more energy efficient to use the microwave, as then I would have exactly the ...
21
votes
6answers
3k views

Does a dishwasher save water in the long term?

I've been considering a dishwasher, but there are a range of different opinions on if they save water (or even energy) or not. Do we have any sources one way or the other?
13
votes
4answers
276 views

What is worse: Wasting water or energy?

I am currently trying to buy a dish washer and just got a washing machine lately and I am really confused whether it is better to buy a machine which uses less water or one which uses less energy. ...
13
votes
1answer
139 views

What is the least environmentally damaging way to start a fire?

I'm used to burning matches to ignite my incense. What is the least environmentally damaging way to start a fire ? to use matches or a lighter ? something else ? Of course a lighter would use ...
17
votes
2answers
746 views

Meat or fish, which requires more energy to produce?

In general it is assumed that the energy that is required to produce a certain type of food is a good surrogate for the total environmental burden of food products. I scanned some studies to compare ...
5
votes
1answer
84 views

What are the sustainability impacts of requiring more and more years of education?

As time has gone on, education requirements to meaningfully have a career has increased incrementally over time. This is true across virtually all fields. This means that we start careers later, are ...
7
votes
4answers
840 views

Gas/cooling strategies for reducing fuel consumption while driving: air conditioner vs windows

Looking at gas milage and air conditioner use, it seems to me I get a significantly better gas milage when I don't use the air conditioner. However, if I roll down the windows, I assume this ...
11
votes
1answer
107 views

Independent retirement vs moving in with the kids

Living in Indonesia at the moment and under long-term discussions regarding whether to move back to the US. One issue is retirement and one aspect of that is sustainability. In Indonesia, ...
5
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2answers
192 views

Would we come to a period of no oil within our lifetime? If so, should we prepare, and how? [closed]

I mean to ask, in order to know, for example, whether someone today should be learning/preparing to lead a post-oil life? i.e no new plastic products, gas-powered vehicles, petrol-generated ...
9
votes
3answers
120 views

Are there projects that use renewable energy sources to create renewable energy sources?

I recently fantasized about a project that starts from a small solar furnace (small, but can melt steel), and a small solar farm (that control the electronics). Then all the energy is used to build ...
14
votes
2answers
99 views

Do “100% renewable” electricity plans increase renewable electricity production?

In the advertising for this year's earth hour in Sydney, Australia, it encourages people to switch from conventional electricity to renewable energy. A number of electricity providers offer "100% ...
13
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2answers
30k 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 ...
6
votes
1answer
82 views

How “clean” is this Ohio State clean coal technology?

Much is being made of the clean coal breakthrough announced at Ohio State this week. The effort utilizes an innovative process called "chemical looping." Typical coal-fired power plants burn coal ...
16
votes
3answers
834 views

Storing food without refrigerator during the winter

I am unplugging my refrigerator for the winter months, I live in the northern United States so the temperature is sub freezing most of the time during winter. I have a semi-insulated garage that is ...
4
votes
2answers
508 views

Is gasoline or Diesel refining less sustainable, per energy output?

Inspired by my own answer here, I'm wondering what the actual numbers are regarding gasoline and Diesel fuel refining. I have read (don't remember where) that refining of Diesel fuel is less ...
4
votes
2answers
148 views

How to monitor energy use in existing office building without submetering?

Our office occupies one floor of a 4-story hundred year old building. We are making tenant improvements to our space, and are interested in lowering and monitoring our energy use, but are unable to ...
10
votes
1answer
79 views

Long-term sustainability concerns of compact flourescent vs incandescent light bulbs

There is a strong movement to push people away from using incandescent lightbulbs in favor of compact flourescent bulbs in order to save energy, but the pollution profiles of these bulbs are very ...
7
votes
2answers
1k views

How can I get my landlord to install better insulation?

We live in an apartment that has a lot of gaps in the doors and windows and poor insulation in the walls. Is there a way to make the landlord fix this? Some sort of property codes or something? He ...
20
votes
4answers
1k views

Is there a difference in insulation to keep heat in or out?

I know that one of the best ways to save energy at home is insulation. The question is, is there a different method for keeping the heat in when it's cold and keeping the heat out when it's warm? I ...
37
votes
6answers
938 views

How can I be more energy efficient in an apartment?

Usually when I see lists of things to do to be more energy efficient, they require one to own their own home. What can I do to be more energy efficient in an apartment? For example, I can't install ...