making coffee

[jockellis]

I think that it may be said that making coffee is inarguably the most important use for electricity yet found by mankind. Womankind would argue that is is the hairroller, but I digress...
What type of coffee maker is the stingiest in terms of wattage usage? You have your countertop coffee maker such as the Quisinart which makes coffee and keeps it hot for a couple of hours, burning.9 kW per hour for 1.8 kW total;
Then you have the single cup coffee makers. I don't know what these burn;
And last, is the new thingee where you pop in a little container much like the creamers you get at a convenience store. These then go through a cycle which makes coffee. Do these burn electricity all the time or just when you are making it?
The countertop model is going to require an inverter putting out 1000 watts. Does anyone know what the other two would take?

[Mike90250]

It's all about the amount of water you are heating up. A single cup, with an imersion heating coil, and a spoon full of instant coffee, will use half as much power as a 2 cup drip system, turned off at the end of brew.

So, the 300w imersion coil is easiest on the batteries, because it draws low amps, even though it's a longer time. 900W for a short time, looses power because of Peukert's Lawof battery losses and wire resistance loss.

And they all loose some power heating air in the room from leakage from the container.

[SpaceOddacy]

I have seen low wattage 12volt coffee makers but keep in mind they are drawing close to 180watts and makes 5 cups of java.

12volt 15amp.

[mountain]

The little espresso coffee machine shown holds a little over 100 ml (100g) of water.
The mass of the aluminumn coffee machine itself is 218g
Liquid Water has specific heat of 4.18 J/g
Aluminumn has a specific heat of 0.90 J/g

(100g x 4.18J/g) + (218g x 0.90J/g) = 614.2 J to raise the temperature of the combined mass by 1 DegC
Assume starting at 0 DegC (OK, we're camping)

To raise the combined mass to boiling will require 61,420J, assuming no external losses. Of course there will be losses.
Mr Google tells me this is equivalent to about 17 Watt-Hours.

Intuitively, this seems like a reasonable number, but I would double it to actually make the desired java.

34 WH, double it again to allow for losses (to air)coffee.JPG = 68 WH
To make that coffee in 5 minutes (1/12 Hour) will require an average power of 816W

Probably I'm over-estimating the losses, 750W would seem sufficient. A nice parabolic solar-cooker would do the job.

http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524442545343&FOLDER%3C%3Efolder_id=2534374302696295