geir oglend wrote:My past experience with electric coffee roasters are that they are very power hungry even at low volume. So to get 10-12 Kgs. of coffee roasted within 12-15 min will need upwards of 100 amps @ 220 volts or more. Now compare that in BTUs with gas and you might fine it cost prohibitive, IMO
I think you are correct that electric roasting gets cost prohibitive once one gets beyond roasting very small quantities. Using your example, 100 amps at 220 volts is equivalent to about 75,000 btu/hr, which is not a very large burner. At the rates that are typical for commercial/industrial utilities in my area, it might cost about $2.30 US for an hour's worth of electric, but only $.75 for the equivalent amount of gas.
A more subtle point might be that roasting with electric is not exactly the same as roasting with gas. For instance, burning natural gas produces plenty of water vapor, so the environment inside a gas roaster is more humid than the environment in an electric roaster. To be honest, I'm not sure how significant this is, though.
You may remember that Todd Carmichael made a big stink
(heh) about how gas roasting bathes the coffee in hydrogen sulphide (an inpurity produced when natural gas is burned). I think he is really off base on this one, however, since hydrogen sulphide is produced by coffee during the roasting process anyway (heat any sulphur-containing substance -- like coffee -- to a relatively high temperature and you will produce hydrogen sulphide).
Christopher Schooley wrote:As far as being power hungry , I can totally see that, but that is why I would be interested in looking at alternative ways of generating electricity (at least part of it) with solar, wind, or even hydroelectric (I saw a pretty cool small scale hydro plant in Panama this summer).
Energy consumption is an important issue that will probably become more and more important for coffee roasters. I'm skeptical that solar or wind will be much help, though. The amount of energy required would necessitate huge, very expensive solar arrays or windmills. Plus, it sucks only being able to roast on windy days or when the sun is shining.
Hydro sounds cool for those willing to locate their roastery near, say, Niagara Falls. Seriously, roasting takes a lot of energy. A cute little waterwheel isn't going to get the job done.