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 [heat]

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9
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1answer
61 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
votes
2answers
101 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 ...
3
votes
1answer
43 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 ...
8
votes
0answers
48 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
52 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
106 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
89 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
86 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
109 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. ...
3
votes
2answers
69 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
164 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
votes
2answers
105 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
vote
2answers
162 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
3k 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
151 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
294 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
227 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
167 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
274 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 ...
13
votes
0answers
547 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
257 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
446 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
291 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
300 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
2k 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
254 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
135 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
639 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
82 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
780 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
106 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
votes
2answers
173 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
119 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
98 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
votes
2answers
22k 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
80 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
579 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
392 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
128 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
75 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
834 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 ...
35
votes
6answers
829 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 ...
15
votes
1answer
116 views

What's the typical energy usage of automatic light switches?

A good way to cope with forgetting to turn of the lights is automatic light switches. But they must be using some energy to do their job. What's the rate of energy use for a typical automatic/sensor ...
37
votes
8answers
3k views

What is an energy efficient way to get fresh air indoors during winter?

Letting some fresh air inside is always a good idea, but during the winter it seems a bit wasteful to fling open the window and let the fresh air in at the expense of all that hot air going out, and ...
28
votes
2answers
186 views

What is optimal “light management” with common compact fluorescent lamps?

With ordinary bulbs, I was used to turning the lights off even when I left the room for a few minutes (mostly because I know that I'll find other business and forget to return :-) ), but I've heard ...
9
votes
1answer
59 views

How can I determine whether roof top wind turbines would be beneficial in my area?

Rooftop wind turbines seem great in principle, but in practice, especially in urban areas their usefulness and efficiency is debated, such as in this article. The most general consensus seems to be ...
29
votes
4answers
431 views

Producing my own energy options in urban area with windows but no roof access?

I'm wanting to produce my own energy, but I live in a condo with no access to the roof. I'd like to produce electricity, so maybe turning that energy into electricity safely. I have windows that have ...