Flummoxed

[linzzay]

So I got all scientific and exercised some long-unused brain cells to try to calculate the energy efficiency of the various tea making methods. The shocking conclusion is that the carafe on the gas stove is far more energy efficient than the hot pot because the hot pot uses so much power. I'm not 100% sure that my calculations are correct, though

Comments

[chiashurb]

On a first review, there is no way your hot pot draws a kilowatt of power.

How do I know? Because power equals current multiplied by voltage (you EE types can just hold back on the complex math for now), and so to get 1 kilowatt out of a 120 V socket, you would need to be drawing 8.33 amps. There's no way the flimsy little chord on a hot pot draws anywhere near that much current.

Put differently, look at the power cable on a legal-limit linear amplifier that runs off of 120 VAC. Now look at your hot pot chord. QED.

[chiashurb]

Although, target.com does list one hot pot as drawing 1.5 kW. I still don't think I believe it though.

[linzzay]

It says "1000 watt" on the bottom of the pot!

[snakey]

this advice from East Riding council *tells* you to use an electric kettle for energy efficiency. I can probably find a bunch of other links too....

[snakey]

For example, the IEE (now the IET, I think?) tells us: "the efficiency of an electric kettle is very high, better than 80%, because the heating element is completely immersed in the water. However, if more water is heated than is required, the practical efficiency can be quite low. Another source of inefficiency is over-boiling, or slow-acting automatic action. For heating small amounts of water, the jug-style kettle, which can handle as little as 0.5 pint, is more efficient than the traditionally-shaped kettle which is not designed to heat small amounts of water|.

I think the point about the element being immersed in the water is a good one...

Practical application

[danorc]

I think the upshot of all this math is this:

People should use which ever the heck one they like better and feels more efficient to them, since the calculations with lower need + more waste is roughly equivalent to higher power draw and less waste.

Also, it depends on what the source of you electric power is. It's probably coal or OIL if it's not wind yet, yes?

Once you get wind power, then your electric kettle makes more sense because it would then be renewably powered versus the fossil fuel natural gas. Also, right now, the natural gas probably burns a lot cleaner than your coal or oil burning power plant.

But, the kettle is faster. Personally, I'd just keep using the kettle until you get wind power squared away. Then you KNOW you'll be right and that it's better, heh.