Hi Robert,
Here are some answers to your questions...
I'm a marine contractor by trade and have owned several tugs and crane barges which all need a generator running continuously....I started building my own generator about 15 years ago when I realized the could be assembled for much less than when purchased as a complete unit..
It sounds like you're thinking way into the future which is a good thing. It would be great to be able to store all the excess energy you generate to keep the engine running in its sweet spot but in order to do that you'd need a slew of expensive/heavy batteries or some other way to store electrical energy as potential energy.
I originally got into the variable speed idea when I realized how much fuel is consumed by a generator just running at rated speed with no load... These generators are usually in the 20-50kW range... most likely not good candidates for an inverter system since a lot of power would need to be stored. A system that uses high frequency AC rectified to DC and then inverted back to AC might also be the way to go if the inverter component becomes more available.. The alternator in your can is a fantastic expample of a reliable variable speed system... I do this on a small scale with my minipetter PM gen where the speed controls the output and there is considerable slip in the alternator.. it's just that there aren't a lot of 30kW variable output alternators available...
I'm also a big fan of CHP off grid power... so I thought a small CHP generator (1-3kW) working with an inverter / battery system seemed like the best way to accomplish this.. using the gen to keep the batteries at 60-70% also leaves room for solar or wind power to be stored.. the 5548 has a peak momentary output of 15kW so it's able to handle most spikes any home would encounter.
Are you grid connected at all? the SW can be made to grid-tie so perhaps you could push back some excess power to the grid and run the meter backwards. If you're not grid connected then ignore this.
I have grid tied the 5548 when it was hooked to the minipetter DC gen just to see how it worked... It works well but only when there's excess DC power... so as the batteries reach full charge it starts dumping into the grid...
Not sure where you get your water from etc but could you channel some excess power to moving water from one place to another place higher up such as from a well or cistern down the hill to a cistern up the hill so that your house needs wouldn't always require a well pump to kick on. I liken this to the hydro plants that pump water from below to up the hill in the low demand periods - at least I heard that's what they do.
power companies think of elevated reservoirs as large batteries... I don't think this is practical for most folks... I'm trying to make something lots of folks can use.. I'd rather store energy in batteries...
Since you're into biodiesel your fuel costs should be lower than most but thats no reason not to try and wring every last bit of benefit out of it as you are trying to do - so you're to be commended for that.
I'm not into biodiesel... I like Veggie oil... unlike biodiesel you don't have to make veggieoil... just filter and pour in the tank... but you do need to convert the engine...
About the only source of large scale inverters I can think of would be from a commercial computer room UPS. Some of them are very large and would almost certainly give you enough juice to do whatever you wanted. The problem is getting one for cheap. Unless someone is decommissioning one and wants to get rid of it (and the batteries too!) then you're looking at a big cash outlay.
Well I'm not into making a one of a kind system... I'd like to make something for the masses..
I'll be interested to hear how you wind up doing this.
I'll be sure to keep posting my progress...
