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Questions tagged [energy]

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], [heating] or [light]. For questions specificially about efficiency, use [energy-efficiency]

29
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9answers
18k views

What to do with old, unused incandescent light bulbs

Over the years, my family has built up a small stockpile of incandescent light bulbs. More recently, we have been replacing our incandescent lights with more energy-efficient alternatives. ...
3
votes
3answers
71 views

What sort of pellet mill can be used for biofuels?

I'm thinking that it would be useful to have a pellet mill at home to turn biowaste into fuel pellets. It would be nice to turn sawdust and wood shavings into fuel pellets as well but that I think is ...
-1
votes
0answers
44 views

How to build a small (8~6 Watt) hydro power system?

1.1The purpose of the hydro-power system: I want to build a small hydro-power system which is capable of charging one USB power bank. I will be the power source by pumping water up with different ...
5
votes
3answers
165 views

What capacity solar system is required for new homes under the California 2019 Building Energy Efficiency Standards (Title 24)?

From the press release (emphasis added): Moving to cut energy use in new homes by more than 50 percent, the California Energy Commission [CEC] today adopted building standards that require solar ...
2
votes
2answers
78 views

Using LEDs to generate electricity

I recently saw an article that said that LEDs can use electricity to produce light or they can turn light into electricity. If this is true, could the excess light that we have coming into our homes ...
15
votes
1answer
144 views

Does transporting plastic offset the benefits of recycling it?

Apparently China has been processing about half the world's waste until this year, and most of that waste is transported over the ocean in large container ships. Recycling plastic uses less energy and ...
2
votes
2answers
65 views

What is marginal energy?

I answered to a question and used the term "marginal energy". The answer wasn't understood by all, so I'm going to expand on the term to illustrate how it works. So, what is marginal energy?
2
votes
3answers
97 views

Energy use for monitor vs pc tower

I work in a few schools where children have been taught to turn off the monitors to save energy. Unfortunately, this is all that they turn off. Every Monday morning I find 30+ computers running with ...
10
votes
4answers
278 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 ...
0
votes
2answers
137 views

Is hydrogen a good way of storing energy from excess hydroelectric generation? [closed]

Referring to hydro electricity generation, a lot of what we produce is wasted as the buyer buys only the minimum generation. What would be the appropriate measure to use that excess energy? Is ...
12
votes
3answers
1k views

Is leaving the fridge door open for, say, 10 seconds a “big deal”?

To use an example, say I need to take out a carton of milk from the fridge, add some milk to my tea, then put the carton of milk back. There are two methods: Method A: Open fridge door. Take out ...
3
votes
1answer
101 views

The least sustainable pathway of the IPCC SR15 report

Looking briefly at the recent IPCC report it presents a number of pathways for keeping global warming below 1.5 degrees celsius by 2100. These follow a spectrum from enormous reductions in consumption ...
7
votes
2answers
142 views

What are the incentives for energy companies promoting energy efficiency?

My hydro (electricity) bills always contain helpful hints on conserving energy: do laundry runs in the wee hours, favor LED over incandescent bulbs, etc. I'm sure many at the big-energy corporate ...
1
vote
1answer
100 views

Is it possible to harvest energy from the storm?

My idea of a device for harvesting energy from wind, waves and especially storms is introduced in the manuscript below. If used in reality, this device will harvest significant amounts of energy from ...
4
votes
1answer
145 views

Is Tesla Powerwall a good investment?

I'm trying to determine if investing in a couple of Tesla Powerwall units to store solar energy is a wise financial decision. My energy cost is $0.1649/kWh. The installed price of the two Powerwall ...
12
votes
4answers
2k views

What is the most sustainable way of making coffee?

Which method of brewing coffee is the most sustainable? The criteria being: minimal waste, minimal energy (no matter where it's produced) I guess for the optimal solution it would be necessary to......
28
votes
4answers
133k 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 ...
-2
votes
1answer
93 views

Why does wind just track the economy

Whenever oil booms, wind booms too. Whenever oil production crashes wind crashes too. The US added about 5GW or 2 million barrels of oil equivalent this year of wind and 300 million barrels of oil in ...
5
votes
1answer
155 views

Are crypto currencies sustainable?

Except generating a different kind of "money value", what is the sustainable value of crypto currencies compared to the energy consumed to generate them? Compared to currencies working with ...
3
votes
1answer
74 views

What is the energy and greenhouse gas footprint of Skysource/Skywater water generator?

The Water Abundance X-Prize was recently awarded to the Skysource/Skywater alliance for: ... developing an easily deployable high-volume water generator that can be used in any climate, meeting the ...
1
vote
0answers
96 views

What ecofriendly well paying jobs in deep learning are there?

I'm currently learning how to train and use neural networks, as I've heard getting into this field would be worthwhile from the people at https://80000hours.org/ Is there any application of this ...
62
votes
10answers
12k 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 ...
4
votes
2answers
115 views

Differences in efficiency between oven, toaster oven, and stove?

Wondering how efficient different cooking methods are (for the sake of example, assume a dish in a cast iron pot heated by stovetop vs. oven). Stove seems to use less energy than an oven (as the ...
6
votes
3answers
107 views

Can the heat generated in a data center be used to heat households and offices?

I've just read the article Microsoft sinks a data center off the Scottish coast (The Verge, 6 June 2018) I understand that the cooling of a data center is a problem. Data centers produce huge amounts ...
5
votes
1answer
89 views

What are the Energy Return on Investment (EROI) values like for biogas?

Biogas seems to be a really great idea but I'm wondering how much energy you get out vs. what you need to put in. I know natural gas is around 10.0 and I was wondering how biogas stacks up by this ...
21
votes
3answers
3k views

Do USB outlets waste energy just like conventional wall warts?

It is widely known that most AC-DC converters (aka "wall warts") continually use electricity, even when no devices are plugged in to them. That wasted energy is often called "phantom electricity" or "...
1
vote
3answers
131 views

Mindset change in developing countries

I've travelled a bit in Africa, Middle East, and Asia. What strikes me, in all of these places, is that often in the most poverty-striken areas, things that people look up to are big cars, and ...
15
votes
3answers
331 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?
49
votes
9answers
2k 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 ...
5
votes
3answers
63 views

Cost benefit analysis of a PV array with racking to set optimal angle, vs a larger array

I'm thinking of installing some panels on the roof. It's unshaded but only pitched at 5 degrees on long run roofing iron. Would I be better off racking at an angle to optimize for winter sun, or just ...
5
votes
3answers
106 views

Could hotels charge guests for the utilities they use to encourage conservation?

I travel often for work and stay in hotels. I have observed that with no direct incentive, it's often hard to stay motivated to make such sustainable choices as taking shorter showers, running the A/C ...
11
votes
2answers
567 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 ...
8
votes
1answer
70 views

What should I do with coal that I have been given?

My wife and I recently moved from London to a lovely old cottage in the countryside with electricity, no gas and a wood-burning stove. We are incrementally improving insulation to make the house more ...
3
votes
0answers
56 views

Are there any articles that describe to correlation between the forecast errors for renewable energy resources, depending on the distance?

In an article by Zhang et al., the authors describe how the (normalized) forecast errors of different renewable energy sources (like solar panels and wind mills) are correlated. To that end, they ...
12
votes
5answers
388 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 ...
6
votes
1answer
438 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 ...
5
votes
1answer
102 views

Energy saving “bonus” for apartment renters

I live in an apartment building with three units, but only one gas meter, one electric meter, and one water meter. As a result, there is no inherent incentive to save water and energy, and no fair way ...
30
votes
3answers
2k 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
1answer
102 views

Does bio jet fuel have a positive energy balance?

This article which was recently trending got me thinking about biofuels: Alaska Airlines makes first flight using jet fuel made from trees. I am not familiar with the numbers for biodiesel, but I ...
-5
votes
4answers
230 views

Getting power from an innovative new mechanism

I am new to StackExchange and trying my best to stay within the rules. I have invented an efficient mechanism -- a rotating mass magnetically attached inside a closed loop (GB 2517244). I am ...
4
votes
2answers
143 views

Being a sustainable Digital Nomad in a Van - First Steps

I am considering the purchase of a retrofitted Ford Transit with a Diesel motor to have a more flexible option for travel and accomodation. Since I aspire to reduce my footprint (and increase my ...
6
votes
2answers
67 views

Will customer preference drive adoption of energy storage the same way as EVs and solar power?

A recent blog post lampooned the fact that the International Energy Agency has under-estimated the growth of solar energy in every single one of their predictions from 1994 to 2016. In the electric ...
3
votes
1answer
101 views

How long will a 12V Koolatron compact cooler last with 12Ah battery?

I'm thinking of purchasing a Koolatron P20 compact cooler and this ExpertPower 12200 battery How long will cooler last with this battery at full charge? Is this the correct battery to use for this? ...
8
votes
1answer
191 views

Laptop nights: shutdown or sleep?

Assuming I use it all day long, should I shutdown my (recent) laptop every night and power it up every morning, or just let it sleep by closing it?
11
votes
2answers
201 views

Should I replace existing inefficient light bulbs?

Similar to this question (except that's about cars), if I can buy more efficient light bulbs than the ones I'm using right now, should I? Or is it better to wait until my current light bulbs expire, ...
7
votes
1answer
365 views

How much energy do wall outlets with USB waste when not actively charging?

In new buildings and homes I've noticed wall outlets with USB chargers popping up more and more: Answers at another question indicate that these outlets waste energy just like traditional chargers ("...
8
votes
2answers
220 views

How is per capita energy consumption related to increasing per capita wealth?

Has there been any global calculation of average increase in consumption of energy per increase of wealth per person? Has there been any such calculations/analyses. And could you perhaps tell us ...
4
votes
5answers
18k 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"?
3
votes
3answers
778 views

Is 3 phase electrical generation more efficient to utilize than single phase?

Is 3 phase power more efficient to generate/use? How difficult or complicated is it going to be to provide balanced single phase load(s) from a 3 phase service? (equipment & controls required) If ...
7
votes
2answers
168 views

Is a pellet stove better than a wood stove?

When we found our house (we're not owners right now), there was already a pellet stove. I don't really appreciate it because it uses electricity (I don't know how much but we now depend on it) and I ...