Apochrypha!! Well at least I learned a new word.
Here is a rather technical report from Victron that was obviously done to promote hybrid applications. It does show how appallingly low genset efficiency is at low loads. See
http://www.victronenergy.com/upload/documents/VE_Marine_generator_test_RVA_07-jan-2008.pdf
And does low load harm a diesel? Well Ski who I respect has said that low load does no harm but no load does (or was it Kevin who said the latter). I prefer to think that more load is better up to a point.
But I do appreciate that if Mama wants it to run everything at once, then you have no choice but to buy a big one.
David
David
Yes, no load is not good. If you are running your generator and it has no load on it, with a good example that was given of a single AC unit cycling on and off that is a bad situation.
Varying loads with some times light, some time medium, and some time heavy is just fine for a generator.
The arguments for a smaller generator generally revolve around cost. Cost of the generator, and to a smaller extent cost of fuel. Those are valid arguments as people have real budgets to deal with.
If you take away the cost factor there is little argument that buying a generator that will serve the peak loads expected will be a hassle free reliable solution in most cases. I am sure that there are extreme examples such as a large boat with huge peak needs for say air conditioners, but they never run the AC units, and with little other needs. In those extreme cases a large generator for the huge loads and a small generator for the smaller loads might be worth considering, but those types of cases are the exception, not the norm for most TF member size boats.
As far as the Vicron study...
We need to remember that any "study" conducted by a company is the result of circular reasoning. The company has a "solution" (their product), and conducts a "study" which they know full well ahead of time that the end result of the "study" will be to promote their "solution". Its a great advertising technique. Create a problem, and offer a solution. Put the correct key words into your web page and all the sudden folks that are worried about a potential issue google it, find your web site, which happens to solve their "problem".