The generator line item I can't leave alone
Thirty grand on, thirty grand off — one row of our electrical budget has changed a dozen times since spring, and it still isn't settled.
There's a row on our ownership worksheet I've toggled on and off maybe a dozen times since spring: diesel generator. On, it adds about $30,000 to the outfitting budget. Off, the battery and solar rows grow until the daily energy math says six people can live without it. It's currently off. It was on for most of June.
The load problem, stated honestly: six of us on the 50-foot cat we're researching, induction cooking because I don't want to chase propane fittings across thirty countries, a watermaker running most days — the Spectra-versus-Schenker question from May feeds straight into this one — two fridges, a freezer, Starlink, autopilot, radar on night passages, and laptops for boat school. My worksheet says 9 to 10 kWh a day. Every liveaboard family I've compared notes with says add twenty percent to whatever you calculated.
The no-generator case starts with solar. About 2,000 watts is realistic on a 50-footer between the coachroof and a davit arch, and in steady trade-wind sun that returns 7 to 8 kWh a day. Most days, that's enough. The shortfall days — squally weeks in the ITCZ, overcast anchorages, night passages with the autopilot working hard — have to come from somewhere else.
The generator case is a Fischer Panda 8000i: roughly $17,000 for the unit and closer to $25,000 once it's mounted, soundproofed, plumbed, and exhausted. Add five years of 250-hour services, impellers, and a spares locker, and I write down $30,000 for the life of the trip. What that buys is a guarantee: a cloudy week in the Marquesas with four kids, a full freezer, and a watermaker that has to run — and nothing about our day changes.
The counterargument I keep scribbling in the margin is that a genset is usually the least reliable diesel on a cruising boat. Lightly loaded, run irregularly, raw-water cooled, and the first thing deferred at service time. The forums are full of boats whose generator became a $30,000 maintenance hobby, and full of owners who say the best upgrade they ever made was ripping it out.
The middle path I keep landing on: skip it, oversize the lithium bank to about 15 kWh usable, keep the 2,000 watts of solar, and hang a high-output alternator on each engine so an hour of motoring puts back 4 to 5 kWh. All-in that's $18,000 to $20,000 — less than the generator alone — and the failure mode is "start an engine," of which we carry two.
So where I actually am: 70/30 against, and fully aware I'd feel differently after one cloudy week at anchor with a dead freezer. If the boat we end up buying already has a genset — most Lagoons and Fountaine Pajots do — I'll keep it and treat it as backup. If it doesn't, which is likely on an Outremer, I don't think I'd add one. That's not resolved so much as postponed until a survey forces the issue.
