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Questions tagged [electricity]

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

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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 ...
3
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1answer
66 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 ...
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2answers
106 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 ...
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1answer
30 views

Are pure or modified sine inverters different?

Just starting my power closet to power my off grid mobile home I've come to question everyone that I belive would know with no concrete answer Is there a difference between using a modified sine or ...
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0answers
53 views

Estimating the power that can be generated by a tidal facility

This is a homework exercise I got: A renewable energy facility has to be built immediately under the Golden Gate Bridge. Estimate the time-averaged power that can, at the resource level, be ...
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4answers
122 views

better to heat house with gas or with electricity?

Is it better to heat house with gas or electricity? We have gas insert and gas heating but am looking at other options for sustainable energy use. Thank you!
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1answer
50 views

Size and reliability of inverter for refrigerator in an off-grid tiny home

I am building an 'Off Grid' tiny home, with my primary energy supply from solar + battery storage. I intend to utilise low voltage everything possible with the exception of a standard home washing ...
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2answers
630 views

How much electric energy would a studio apartment use per month if everything inside is powered by electricity (heater, water, stove, etc.)

How much electric energy, on average, would a typical one-person studio apartment consume per month in the winter if everything inside is powered by electricity? Additional Information: Apartment ...
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82 views

How much, if any, does resolution effect the net power consumption of watching online video?

I watch a lot of online video. I'd assume that for example videos on Youtube in 720p use less power than the same videos in 1080p. I think this might be because: more power is used by sending network ...
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4answers
229 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 ...
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1answer
315 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 ("...
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1answer
117 views

Best course of study for learning to build electrical systems and supporting electronics for an off grid power station

I'm working on constructing a totally self sufficient (i.e. totally off grid) building in the wild. I do not want to restrict myself to any particular source of power (hydro, solar, wind etc), but I ...
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104 views

Do higher electricity prices cause people to use less?

Demand for gas is elastic... I've read that cars in Europe are, on average, more efficient than cars in the US due to significantly higher taxes on gasoline. ...but not for electricity? In the ...
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2answers
2k views

Is leaving an electric oven on to heat bad for the oven?

We leave our oven on with door open to heat our trailer Will that cause the ovens thermostat go out it's an electric stove with four burners to boil water also for heat.
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1answer
109 views

How much energy would it cost to stabilize 2 tons of water at 70 degrees?

So what I'm trying to figure out is the efficiency of energy usage between heating up 2 tons of water from 5°C to 70°C everyday (during winter) with a certain given time (let's say one hour) and ...
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1answer
50 views

Office building electricity use [closed]

A typical office lease says the tenant has 1.5 watts of electricity to use per sq.ft. for lighting and 3.5 watts of electricity per sq.ft to use for computers etc. anything over this they say extra ...
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1answer
70 views

How can I find out what a reasonable rate for installed solar is?

I'm looking to have a ~20kW grid-tied solar system installed at our property in Ontario, Canada. I've been searching and reading but am unable to find current (last year or two) data on how much such ...
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3answers
114 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 ...
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1answer
188 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 ...
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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 ...
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2answers
237 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 ...
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2answers
825 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 ...
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3answers
392 views

Does the price of polysilicon (for solar PV panels) depend on oil prices?

The assertion that the answer to this question is "yes" was made in an answer to another question here: Which solar power technology has the highest energy return on investment (EROI aka EROEI)?. The ...
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1answer
209 views

Does a PV panel take more energy to build than it generates in its lifetime? [duplicate]

Industrial energy costs are $1 per million BTU (MMBTU) or 300kWh, or $3*10^-6 per watt hour (Wh). http://www.eia.gov/consumption/manufacturing/ Solar has 1 kg of 9n silicon per 100W, at $20/kg. ...
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2answers
88 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 ...
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140 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 ...
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1answer
359 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 ...
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3answers
2k 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 "...
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1answer
97 views

Hydro-electric generation from roof-collected rainwater

Can electricity be produced from running water by the use of dc motors? For example rainwater collected from from the roof of a very tall house say 15m high is directed through a pipe and at it's exit,...
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1answer
142 views

Energy requirements for sustainable food production system

Overview Consider the following system for sustainable food production: The purpose of this system is to provide an environmentally-friendly, semi- (or fully-) automated means to produce food for ...
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4answers
195 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 ...
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2answers
3k 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 ...
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78 views

Is there a way to tell (or estimate) the electricity consumption of an arbitrary household item?

I often wonder how much energy a given item in my home is using. Examples include: the clock on my microwave my espresso maker an electric water kettle my phone charger (when no device is attached) ...
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1answer
45 views

Coupling a solar DNI dataset with demand loads at different time zones

This question is about analyzing the potential of concentrating solar power (CSP) to meet different load curves, each load curve at one time zone. I would like to know the best way to analyze the ...
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2answers
122 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 ...
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1answer
251 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 ...
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1answer
221 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 ...
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4answers
443 views

Pool, sauna and shower with electric heating and solar thermal vs gas heating?

I have four things that need to be heated on my house: Pool (28.000 liters solar thermal heated) Jacuzzi (I think that is like 400-600 liters is gas heated) Showers (actually they are all electric) ...
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0answers
23 views

How can I get my landlord to improve my apartments heating efficiency? [duplicate]

I am renting a unit in an older building 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 ...
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1answer
56 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 ...
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1answer
156 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 ...
7
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1answer
92 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 ...
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2answers
588 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 ...
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1answer
108 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 ...
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1answer
211 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 ...
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5answers
17k 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"?
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1answer
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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 ...
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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 ...
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21k 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 ...
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153 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 ...