15
votes
Are plastic cups more environmental friendly than ceramic mugs?
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 ...
- 14.5k
13
votes
What form of electrical lighting has the smallest energy-footprint?
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 ...
- 231
12
votes
Are plastic cups more environmental friendly than ceramic mugs?
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 ...
- 2,116
8
votes
Which is more energy efficient? Heating ten 1L water separately or one 10L water directly
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 ...
- 3,875
8
votes
Accepted
How much energy would it cost to stabilize 2 tons of water at 70 degrees?
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 ...
- 14.7k
8
votes
Accepted
Does transporting plastic offset the benefits of recycling it?
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 ...
- 11.8k
8
votes
How to ensure you are using efficient chargers for cell phones, laptop computers, and other electronic devices?
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 ...
- 11.8k
7
votes
Accepted
Which is more energy efficient, a washing machine express wash, or normal?
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.
...
- 5,973
7
votes
Electrical usage data logging with wireless data transfer
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 ...
- 862
7
votes
How to choose between an electric, natural gas, or heat pump clothes dryer?
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 ...
- 2,579
6
votes
Should I worry about the minimum mark on our kettle?
I agree with Fred in that it seems logical that a minimum amount of water would be required to help prevent overheating by the element. It's likely though that the manufacturer has specified a fairly ...
- 8,755
6
votes
Should I worry about the minimum mark on our kettle?
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 ...
- 3,517
6
votes
Anything similar to GravityLight that can be readily purchased?
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 ...
- 14.5k
6
votes
Accepted
How much, if any, does resolution effect the net power consumption of watching online video?
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 ...
- 11.8k
6
votes
Accepted
For overnight heating, is it more efficient to use an electric space heater in a bedroom or a whole house natural gas furnace?
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 ...
- 14.7k
5
votes
Does it make any difference to charge my electronic devices using an USB port?
Computer PSUs generally only hit their rated efficiency when well loaded. Most desktop PCs have larger PSUs than they need, to allow for expansion, and so they are not fully loaded. Consequently it is ...
- 3,690
5
votes
Accepted
Does it make any difference to charge my electronic devices using an USB port?
To give a definite answer would require a lot of research and it would probably be quite impossible to give a "for sure" answer because there are some variables. Some computer power supplies are much ...
- 676
5
votes
Which is more energy efficient? Heating ten 1L water separately or one 10L water directly
The heat loss will be proportional to the surface area. If you boil ten litres, one litre at a time (rather than all ten litres at once), there's typically a lot more surface area, so the heat loss ...
- 14.7k
5
votes
Accepted
How feasible would a gas-powered electric-engine based car be?
It would work, but there isn't much reason to do it. If you do this without batteries, you are giving up most of the potential advantages.
If you simply have an internal combustion engine (petrol or ...
- 3,690
5
votes
Is 3 phase electrical generation more efficient to utilize than single phase?
I'm going to assume you'e in the USA since you're using Imperial units.
1) Is 3 phase power more efficient to generate/use?
In bulk, yes. Three phase (or sometimes 6 phase/3 phase 220V in low-...
- 3,875
5
votes
How much energy am I harvesting?
Energy in the pumped water
54 gallons is about 200 L, equivalent to 200 kg
30 feet is about 9 m
Using the formula @JanDoggen mentioned:
m ⨉ g ⨉ h = (200kg)(9.81m/s²)(9m) ≅ 18,000 kg*m²/s²
This is ...
- 11.8k
5
votes
Most cost effective heated flooring?
It will depend on your local cost of fuels and of equipment.
The most energy-efficient way to do it would be to have a ground-source or water-source heat-pump that fed your under-floor heating. ...
- 14.7k
5
votes
Accepted
Keep my hands warm while working on a laptop?
I use a pair of wool fingerless gloves. They don't impair dexterity and even though they leave fingers exposed they cover enough that my entire hands remain comfortable.
- 1,603
5
votes
Accepted
Do solar panels generate more electricity in hot or cold climate?
If the amount of radiation stays the same, solar panels produce more energy when they are cooler. Heat causes efficiency to suffer.
However, this is assuming the radiation amount is the same. Usually ...
- 4,786
4
votes
How feasible would a gas-powered electric-engine based car be?
The concept has been used in heavy duty mining trucks for decades. Diesel powered locomotive engines power an electric generator that then powers electric motors located on the rear axles of the ...
- 3,517
4
votes
Which is more energy efficient, a washing machine express wash, or normal?
To supplement the existing answer, it's worth mentioning that using a hot wash may well incur more electricity costs in water heating than the washing machine incurs in actually washing, assuming you ...
- 8,755
4
votes
Accepted
Energy requirements for sustainable food production system
Given the uncertainties in many of your numbers, your answer is consistent with Nate Storey's.
Your assumption of 303 lm/W for LEDs doesn't look plausible to me - that's very different to the sort of ...
- 14.7k
4
votes
Should I worry about the minimum mark on our kettle?
There's another reason for minimum water levels: when the steam is used to trip the temperature sensor, a certain minimum amount of steam (or rate of steam delivery) is required. This will depend on ...
- 2,116
4
votes
How much gas does it take to heat water from 15 to 60 degrees C?
The amount of energy needed
From EnergyNumber's answer to the electricity version of this question:
...the energy needed is 180,000 x 45 x 4.2 = 34 MJ
1kWh = 1000W x 3600s = 3.6 MJ
Hence,...
- 11.8k
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