Andy -
An interesting article at that link. I just had time to skim it this morning. However, it appears that the up to 98% efficiency they refer to is for just an electric motor. If I recall, just the generator head itself might have up to 95%. That does not deal with mechanical losses and the like. I'll have to read it in more detail tonight
While I don't doubt that it is possible to build a gas engine or tractor-driven generator with much higher than around 67% efficiency, I've never seen one that significantly departs from that rough rule of thumb of 2 HP for every 1 KW of continuous output at any price (at least not in a typical homeowner size range -- a few KW rating up to 10 or 15 KW). 98% efficiency of the overall system would mean something like a 6.8 HP engine driving a 5 KW generator (continuous rating, not surge rating). Have you seen something like this for sale? I haven't, but would be interested if there was something on the market.
John Mc
