In my induction cooking article I shared the results of the experiments I conducted that showed that electric cooking with an induction cooktop and small oven powered from renewables was not practical, at least without festooning our boats with an unseamanlike array of solar panels and wind generators, and marginal even then. And therefore induction cooking is not green, at least unless we are willing to settle for very limited stovetop cooking, and no baking or roasting, as well as cutting our other electricity use to the bone. And given that, I realized, particularly after the excellent discussion in the comments, that much (maybe most) of making a rational decision about switching to electric cooking is dependent on understanding what's required for an efficient generator-based electrical system. And then I realized that induction cooking was a red herring since most of this analysis will be relevant for any live-aboard cruiser who is considering a lifestyle that will require more than about 250 amp/hours at 12 volts (3 kWh) of electricity daily. I emphasize "about" because numbers like this vary based on usage, and user, profile. For example:
- the number where a generator is required is less than 250 amp/hour for people like Phyllis and I who abhor the clutter, windage and vulnerability to storm damage of more than a couple of decent-sized solar panels securely mounted to an arch;
- but probably more for those cruising trade-wind areas, where wind generators can do more, assuming you are willing to take the windage hit and put up with the noise—modern wind generators are quieter, but I don't classify them as quiet.
Why The Big Deal?At this point, many of you are probably wondering why I'm making such a production out of this. Surely we just install a generator and have near unlimited power, end of story? True, but in so doing you would be following in the footsteps of most marine generator users of the past: producing a bunch of electricity in the cheapest possible way (capital cost) and the planet be damned. You see this often on large motorboats where many electricity consuming loads are installed—electric cooking, household fridges, freezers, icemakers, air conditioning, etc.—and the generator(s) are sized to supply the peak loads. This is horrible since there are few things more inefficient than an underloaded generator. Wait, it gets worse, because someone might want a cup of tea or to turn on the air at any time, these generators are often run for hours or even days under tiny loads—bad for the generator as well as the environment.
The Best SolutionObviously the greenest possible solution is to simply cut our consumption, including scrapping the idea of electric cooking, to the point where a seamanlike renewables array can do the job, perhaps supplemented with an occasional charge from the main engine; however, if you do the latter every day, you will be greener with a generator (done right).
Bottom line, a fundamental that often gets missed in all of our excitement about cool technology is that cutting consumption is always the greenest option.
A Better SolutionBut given that, most cruisers still seem to want one or more of the following:
- Electric cooking
- Washing machines and dryers
- Big freezers—Phyllis' and my environmentally bad habit
- Air conditioning