Questions tagged [electricity]

Questions concerning the production or use of electricity in a sustainable way.

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42
votes
6answers
840 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 ...
34
votes
2answers
582 views

What’s the best strategy for turning off CFLs that will save energy but not reduce lifespan so much

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 ...
33
votes
3answers
3k views

Are electric cars as environmentally friendly as we think they are?

Given the fact that the average lifetime for a car battery is 3 years and all of the batteries end up at a landfill at the end of their lifetime, how sustainable are electric cars in providing a ...
31
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 ...
25
votes
5answers
14k views

What types of plugged in electronics use energy even when turned off?

I just need some convincing before I start unplugging everything. I kind of assumed that USB type computer, phone, or printer chargers would use electricity. And obviously my computer, sound system, ...
23
votes
10answers
767 views

How can I manage my fridge's contents better?

Sadly, about 30-50% of the Western world's food is thrown away. Personally, I waste about half of my food, due to poor fridge management. I forget what I have bought and find expired food located in ...
22
votes
4answers
780 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 ...
22
votes
2answers
175 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% ...
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 "...
20
votes
2answers
800 views

Should I keep laptop and cellphone batteries fully charged, let them die before charging, or something in between?

Generally, is it better to let laptop and cellphone batteries fully die before recharging, to leave them plugged in constantly even when charged and not in use, or to unplug them once they are fully ...
19
votes
8answers
2k views

What is an easy way to cool off during the summer without electricity?

What are some easy ways to stay cool during the day without using electricity?
16
votes
3answers
6k views

Would monocrystalline or polycrystalline solar panels perform best in a UK climate?

If I were to get solar panels installed on the roof of my home, in the UK, what type should I choose? There appear to be three main types, and at present the choice appears to be between the ...
16
votes
3answers
2k views

What's the average efficiency of pumped hydroelectric energy storage facilities?

Pumped hydroelectric storage has, to date, been the most scalable way to store electricity (in this case, in the form of gravitational potential energy), allowing us to spread the time between when ...
14
votes
3answers
10k views

How to build a waterfall powered electric generator?

Want to build one of those old-style water wheels powered by a waterfall. Is there a more efficient way than the ones that were around since the start of the industrial revolution?
13
votes
3answers
27k views

How much power does a computer monitor left switched on use?

Its a little niggling annoyance that always gets me in my office that when I work overtime and leave the office after everyone else I see row upon row of little orange lights where people have turned ...
12
votes
4answers
317 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 U-...
12
votes
2answers
3k views

Are there any viable DIY or commercial solutions to convert waste heat to electricity?

Apparantly there are some advances in converting heat to electricity such as here or here. But are there any commercial solutions/devices/DIY projects or is this at the moment (as stated in the ...
12
votes
1answer
6k views

Which types of spare electric motors from common consumer appliances are suitable to repurpose as generators?

I've heard that washing machine motors (in particular, the Fisher & Paykel branded ones which are local to me in New Zealand) are quite suitable for repurposing for generation use. Other types ...
11
votes
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 ...
10
votes
4answers
202 views

Why are electrical cars encouraged but is electrical heating discouraged?

Electrical cars are very much promoted for a sustainable future, because they do not rely (directly) on fossil fuels. In the meantime, most of the electricity is produced with fossil fuels, such that ...
10
votes
2answers
2k 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, ...
9
votes
2answers
161 views

How worthwhile is it to use energy during daylight to take advantage of grid-based solar power?

Common sense is telling me to try to do things like vacuuming, laundry and cooking at times of maximal sunlight during the day so that more of the electricity I use comes from solar power generators ...
9
votes
2answers
139 views

How can electricity grids successfully incorporate high (50%+) penetrations of PV and wind?

Although most of the renewable energy currently consumed by the world can be turned on and off at will pretty easily (hydro and biomass), there are two potentially huge supplies, wind and PV, that are ...
9
votes
2answers
145 views

Does it make any difference to charge my electronic devices using an USB port?

I work with a computer and I was wondering if using its USB ports to charge the devices that I use the most (mostly my phone and my e-reader) while working as opposed to charging them using a normal ...
8
votes
3answers
145 views

How the grid is managed in markets with high renewable energy penetration

As many people know, many of the renewable energy technologies generate fluctuating power dependent on availability of the power generating source e.g. wind and solar et al. Balancing power must be ...
7
votes
1answer
272 views

Transmit solar over multiple time-zones?

I heard that at big voltages (10 000+V) the energy loss along a wire is very small. Unfortunately I've got little electrical knowledge, but this sparked up a question: Considering that peak ...
7
votes
2answers
985 views

How to save heating energy with roommates?

I live with roommates, and am only a renter not owner. I'm looking for ways to help with energy conservation despite this. We have one roommate who is wasteful about leaving lights on and, in ...
7
votes
2answers
286 views

Anything similar to GravityLight that can be readily purchased?

Ever since it was first mentioned in a popular news site, I've always been interested in GravityLight. But I've never been able to go to a store or a site and just buy it. Is there anything vaguely ...
7
votes
1answer
395 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 ("...
7
votes
1answer
179 views

How efficient is it to use an electric car as storage for the energetic overload generated during sun hours (peaks) by solar panels?

I guess that the question is quite self-explanatory. I am hoping to invest in a solar panel soon, but I am a little worried about it getting inefficient once government subsidies run out and the ...
7
votes
2answers
955 views

Can I connect an inverter directly after an MPPT controller, with no battery?

Is it possible to connect a 12VDC to 220VAC inverter to the output of an MPPT solar charge controller, with no battery? This will be cheaper than having a full solar inverter, which can be really ...
7
votes
1answer
2k views

Washing on delicate or permanent press…is this more sustainable and also gets your clothes clean?

Is it more sustainable to do your wash using the delicate or permanent press modes? I can tell from observing the different kind of washes is that the machine spins less and spins more gently. If so, ...
7
votes
1answer
120 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 ...
7
votes
3answers
1k views

What Makes an Oven Eco-Friendly?

I am currently in the market for ovens and I wanted to know what makes on oven eco-friendly, whether it's electric or steam, without compromising reliability. I want a oven that not only benefits me ...
7
votes
2answers
675 views

What are the physical limits on wind turbine size?

Wind turbines just seem to keep growing. Predictions a few years ago that a 120-metre diameter rotor was going to be the maximum, have turned out to be wrong, and 154-metre rotors are being installed ...
7
votes
1answer
95 views

What scope is there for price reductions in photovoltaic inverter costs?

In almost all of the world (except the USA, which has specific local cost challenges), system photovoltaic (PV) costs have come down a lot, to about €2 per installed watt. A large part of the ...
6
votes
4answers
236 views

Why are my LED light bulbs so short lived?

I thought the idea of LED is, that the light bulb has a very long life and uses very little electricity. I have not invested in full LED lighting but tried the LED bulbs, you screw in your normal ...
6
votes
1answer
198 views

Can 140 square miles of solar panels power the US?

In the book The Upcycle (copyright 2013) by William McDonough and Michael Braungart, the authors make the following claim: ... consider exactly how much desert area covered in solar collectors ...
6
votes
2answers
92 views

The more miles a car drives, the more economical battery packs become?

I was reading here: Here’s How Electric Cars Will Cause the Next Oil Crisis, that the more miles an EV drives, the more economical battery packs become. I don't understand this assertion. I see ...
6
votes
2answers
125 views

How would one go about judging the sustainability of BitCoin or other cryptocurrency

I know BitCoin uses a lot of electricity for its mining, but how is this comparable to the banking system? Also, other cryptocurrencies, like PeerCoin, claim to be more environmentally friendly by ...
6
votes
1answer
276 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 ...
6
votes
1answer
62 views

How to interpret the efficiency of ground-source heat pumps?

This page at energy.gov says the following about geothermal (or ground-source) heat pumps. Geothermal heat pumps (GHPs), sometimes referred to as GeoExchange, earth-coupled, ground- source, or ...
6
votes
1answer
174 views

Where are the world's wave resources, beyond the UK and Portugal?

Are there maps of the global resource for near-coast (<200km or so) wave power? I know that the UK has a particularly good resource - the kinetic energy in the waves in UK waters amounts to an ...
6
votes
2answers
4k 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 ...
6
votes
1answer
111 views

What is the global environmental impact of holiday decorations?

Just a random curiosity question here. How much do all the holiday lights and other such decorations affect the environment? Relative to the footprint of a house a set of outdoor lights is probably ...
5
votes
3answers
55k views

How many kilowatt hours of electricity does it take to heat 180 litres of water from 15 to 60 degrees C?

I think this calculation uses the specific heat capacity for water, which is from memory a bit over 4. Can someone please do the math? Also, if we assume electricity costs $0.30 per kilowatt hour, ...
5
votes
2answers
4k views

Which is more energy efficient, a washing machine express wash, or normal?

My electric washing machine has an express wash button (they seem a common feature) that reduces the washing time by a lot. My first thought would be that using it would save energy because of the ...
5
votes
1answer
70 views

Is electricity used at night more likely to be renewable?

Discussing charging my electric car with a colleague recently I argued that since (in Ireland) our renewable energy sources are mainly wind and hydro, since I charge my car at night the mixture of ...
5
votes
2answers
432 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 ...
5
votes
1answer
366 views

Electrical usage data logging with wireless data transfer

Does anyone know of a wireless energy usage capture device, that one can attach to an appliance and find out the energy usage? I know that there are certain energy monitors that do the job to some ...