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There are two main categories to consider here. The first is to improve the efficiency of how your home is kept warm - either by increasing the efficiency of the heating system, or by reducing the rate at which warmth is lost to the outside. If your home is quite "leaky" then major gains can be made this way quite cheaply. Other answers to this and other ...


13

i signed up just so i could make this comment. THelper♦ provided a good link to a DOE report on this topic, which i was researching because my roommate is skeptical about the advantages of efficient bulbs. the report THelper♦ cited has the following bar graph that pretty much answers the question:


13

It's correct that the production of 1 ceramic mug requires much more material and energy than the production of 1 plastic cup, but this isn't a fair comparison. Plastic cups are generally used once or perhaps twice and then disposed of. A ceramic mug is likely to be used several hundreds of times before it breaks and is thrown away. Let's assume you use a ...


12

A: Insulate your attic. This can be done in an afternoon. Put 12-16" total in that space. B: Seal the leaks: Weatherstrip the doors and openable windows. All electrical outlets are punctures in the outside wall. You can buy gaskets for them, or you can make them out of the styrofoam meat trays you get from the grocery store. C: Heat shrink ...


12

No. With nothing plugged in there is no circuit, so no current can flow. An exception to this is if the socket or the switch has an indicator light - usually a neon one - that is illuminated when the switch is on. In that case the light will use a (very small) amount of power.


12

Generally, it makes sense to save power, even during the winter. The difference between space heating and waste heat The main difference between home heating systems and waste heat from electrical appliances is the way the heat is released, and where it's released. Many types of home heating systems are designed to provide heat in a specific way, such as a ...


10

You've pictured a disposable plastic cup. If you assume that you can use it a few times, then you might consider that you get through one a day. A ceramic cup lasts until you drop it. The cup in your photo is only for cold drinks anyway. Paper or expanded polystyrene are usually used for hot drinks. This link runs the numbers: In summary, ceramic is best. ...


9

Yes, it matters, a little, but it also depends on your location. In your car, the process of converting fuel to movement is pretty inefficient (about 25% to 30%, according to this). That movement (kinetic energy, if you're a physicist) is then converted to electrical energy with an efficiency of 75% to 80%, giving you an overall efficiency of 18.75% to 24%. ...


8

tl;dr: Yes, lowering the room thermostat at night will generally help save energy, assuming we are in the heating season (winter), rather than the cooling season (summer). Let's take two points in time, one before the night, one after it. Let's choose them so that the dwelling has the same amount of heat energy contained within it at each point, so all the ...


8

Unless she's actually using the 1-2 litres of tea each time, there's more savings from simply boiling less water. We bought a small electric kettle with a flat bottom and glass walls to encourage people to boil the one cup of water they actually want, and that has worked reasonably well. If you can make 10 litres of boiling water and insulate the container ...


8

The stabilisation energy rate will be exactly exactly equal to the rate at which energy is lost. Assuming the tank is closed, so there are no evaporative losses, there are two other ways energy is lost. Firstly, from conductive losses through the surface of the tank. That will depend on the thermal conductivity of the tank, and on difference between the ...


8

tl;dr: No, shipping plastic waste to China for recycling does not offset the benefits, as it reduces the net energy savings by 3% or less. Polyethylene, The most common plastic According to Wikipedia, polyethylene is the most common type of plastic. There are three main categories of polyethylene (also from Wikipedia): PET (polyethylene terephthalate), ...


7

On the financing front: I don't know about the situation in the US, but some countries have schemes whereby grants or favourable loans are available for improving the energy efficiency of housing stock. For example, in the UK there is the "Green Deal". These schemes will vary in their usefulness versus the amount of bureaucracy involved, but are worth ...


7

As for federal tax credits, I believe they only apply to 'principal residence' so you must both own and live in it. However the landlord may be able to write it off as a cost if she pays the bill, for some relief. Check the energystar.gov site for details on what qualifies for tax credits: http://www.energystar.gov/index.cfm?c=tax_credits.tx_index . ...


7

Strictly speaking, your heat pump's CoP is not affected by the outside temperature, but by the difference between inside and outside temperatures. Given that there is a fairly narrow range of interior temperatures that we might want, that is nearly equivalent, but it does mean that there is only a limited extent to which this "pre-heating" approach can work -...


7

As I understand it, in the scenario that you describe, the heat pump is not doing anything useful, and the question simply boils down to "Is it best to use a resistive electric heater through a central heating system, or to use radiative (infra-red) heaters in the rooms that are occupied". That's quite a simple one to answer: Either system is 100% efficient ...


7

The wattage given on the fixture refers to the maximum that can safely be used. That will be dictated by two things: The internal wiring of the fixture, and the heat that it can tolerate. In reality the additional 6W of the three 42W lamps that you are using is probably not going to be a problem, but it would be wrong of me to advise you that it's OK - you ...


7

One of the key considerations here is how much time the appliance will spend turned on. If an old CRT TV is hardly used, then the environmental footprint of continuing to use it is very low, even if it uses 5 times as much electricity as an LCD one. Secondly, the way the electricity is generated makes a substantial difference. If renewable energy is used to ...


7

As for saving energy in the fridge, vegetable storing does not make a difference.* If you want to prolong the life of your produce to reduce waste, it depends on the vegetable. Many veggies and greens generally need to 'breathe', so non-sealed bags/containers or just in the 'crisper drawer' is good. You can buy specialty bags such as perforated ziplocs or ...


7

I think a "general principle" is that "express wash" usually means one or more of the following reduce the wash cycle reduce the spin cycle skip a rinse cycle (e.g. by not using any softener) etc. In other words, rather than "same washing in less time" you get "less washing", but still enough for not-so-dirty clothes to get clean. This means that the ...


7

It sounds like the Kill A Watt wireless might be what you are after. For more alternatives keep reading. There is another product line called the Watts-Up that has USB connections to computers on some models, and a built in web server on the high end one. The high end one can be made to work over wireless with an adapter. The USB only versions could be used ...


7

You need neither a tumble dryer nor a drying cabinet. I haven't used either for years, and we are a two person household in a 36m² studio apartment in England (so winters are rather humid). By far the most sustainable way to dry clothes is by drying on a line or a clothes horse. Tumble dryers use a lot of energy and damage your clothes. Drying cabinets ...


7

Power ratings -- choose level VI Take a look at any external power supply (EPS) you have lying around -- you should notice, along with all the regulatory markings, a roman numeral I through VI in a circle. Here are four that I just dug up in my house: These indicate energy efficiency standards for EPS starting with the California Energy Commission in 2004 (...


6

Summary We typically get about 20-30 times as much energy out as energy in. The range in the literature is wide: 4.6-40. Overview The ratio of energy generated to energy invested will vary, depending on a lot of issues. Here, I'll only consider grid-scale wind power, i.e. turbines of 0.5MW rated capacity upwards. That's because they represent the ...


6

Space heaters (yes, even those fancy quartz ones) use electric resistance to generate heat. If your home's HVAC system is switching to resistance heating when it's cold outside, replacing it with space heaters should, in an ideal world, neither increase nor decrease your energy usage. If you drop the whole house temperature by 5 degrees and use a weak space ...


6

I asked my late father (an electrical engineer) this very question years ago and he said that essentially, the entire cost of a solar panel is the cost of the energy to make it. You dig dirt out of the ground and apply energy to turn that into metal, glass, etc, then you use energy to ship parts around and to assemble them into a panel and ship the panel, ...


6

In older kettles with an exposed heating element it does matter. If the element is not covered with water it will overheat and burn out. With newer kettles without an exposed heating element you may risk reducing the useful life of the kettle as a certain amount of water will be required to absorb and dissipate the heat produced by the heating element.


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The big advantage of GravityLight is that you can pull the weight once and then you have electricity for a relatively long period (I read somewhere it's 30 minutes). This is ideal when you need to have both hands free to do some work. This long period is also a must if you want it to replace the kerosene lamps that are currently used in rural Africa. The ...


6

The Natural Resources Defense Council commissioned a study in late 2015 to understand the energy consumption from 4K TVs, titled The Big Picture: Ultra High-Definition Televisions Could Add $1 Billion to Viewers' Annual Electric Bills. While this doesn't exactly answer your question as regards the resolution of You-Tube videos, it gives some solid clues. ...


6

In terms of energy-efficiency within your own home (i.e. when we ignore energy losses outside the home), it will almost certainly be more efficient to use the electric space heater. It will be close to 100% efficient, and all the heat will get delivered where it's needed. So there will be reduced heat loss from the rest of the house. Fossil-gas furnaces tend ...


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