GREEN EN­ERGY

If your plans in­clude long-dis­tance sail­ing, a wind gen­er­a­tor is a log­i­cal ad­di­tion to a so­lar panel ar­ray. Peter Nielsen re­cently bit the bul­let and in­stalled one

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Peter Nielsen in­stalls a new wind gen­er­a­tor

So­lar pan­els or wind gen­er­a­tor? There’s lit­tle doubt that for State­side cruis­ing, es­pe­cially down South where the amount of sun­shine out­strips the strength of the wind for much of the year, so­lar is top of the list for live­aboard and long-term cruis­ers. Hav­ing seen what even a small 50W panel can do in a North­east­ern sum­mer, I had been plan­ning to bump up the so­lar ca­pac­ity on our Pear­son 39-2 project boat to 250 watts, but won­dered if this alone would be enough.

I hadn’t se­ri­ously con­sid­ered a wind gen­er­a­tor un­til I cruised the Gre­nadines on a char­ter boat a cou­ple of win­ters ago. In ev­ery an­chor­age, it seemed most of the se­ri­ous cruis­ing boats boasted not only an ar­se­nal of so­lar pan­els, but also a wind gen­er­a­tor whirring mer­rily away in the brisk tradewinds. Since fu­ture cruis­ing plans in­clude lengthy pe­ri­ods off the grid in tradewind ar­eas, I came home and started my re­search.

Ev­ery such project should start with an as­sess­ment of the boat’s power needs. Once you’ve de­ter­mined the amount of cur­rent your fridge, stereo, lap­top, lights et al con­sume over 24 hours, you’ll have a fair idea of not only the size of bat­tery bank you’ll re­quire, but how many amps your charg­ing de­vices will need to de­liver. There is an ex­cel­lent work­sheet on the West Ma­rine web­site that can help you with this.

The idea of course is to mim­imize (and if pos­si­ble elim­i­nate) the need to run your en­gine to keep your bat­ter­ies in a de­cent state of charge. I don’t think I’ll achieve the lat­ter state of Nir­vana, but go­ing three days or so with­out the need for ad­di­tional charg­ing be­yond what wind and sun can pro­vide seems a workable ob­jec­tive.

Even though the boat’s needs are mod­est, the only re­quire­ments be­ing the abil­ity to run the fridge 24/7, power a stereo and lap­top at an­chor and al­low un­lim­ited use of nav­i­ga­tion elec­tron­ics and au­topi­lot un­der­way, it be­came ap­par­ent that the 200W of so­lar pan­els I’d planned to add would fall short. Per­haps the ob­vi­ous an­swer would be to in­stall more pan­els, but with­out in­stalling an arch there would be no room to do so—and I wanted to min­i­mize cock­pit clut­ter.

My wind gen­er­a­tor short­list was in­deed short: the tur­bine had to be func­tional at medium to high wind-speeds—none of them gen­er­ate much power be­low 8 knots or so—it had to be tough and re­li­able, and it had to be quiet. I’ve shared an­chor­ages with boats whose wind gen­er­a­tors sounded like ap­proach­ing he­li­copters. The de­ci­sion to in­stall a Ger­man-made Su­per­wind 350 took all of those fac­tors into ac­count. It’s a heavy unit, built to com­mer­cial spec­i­fi­ca­tions,

and with its auto-feath­er­ing blades it is able to be left unattended even in strong winds. Al­though it would not start de­liv­er­ing se­ri­ous amps un­til wind speeds were in the low teens, it would start at least trickle-charg­ing as soon as the blades started spin­ning at 8 knots or so, and in­ter­net re­search in­di­cated ex­cel­lent re­li­a­bil­ity. (For more on wind gen­er­a­tor tech, go to sail­magazine.com/ diy/know-how-wind-gen­er­a­tors).

LO­CA­TION, LO­CA­TION, LO­CA­TION… Once I’d set­tled on the equip­ment, there arose the gnarly ques­tion of where to mount it. This would not be much of an is­sue on a broad­sterned mod­ern boat, but the com­par­a­tively svelte der­rière of a 1980s Pear­son did not pro­vide me with many op­tions. Nor had I ruled out adding an arch in the fu­ture, in which case the mount­ing point would likely be changed, so I did not want to mar the tran­som with a pro­trud­ing mount, and nor did I want to spend a for­tune on a heavy stain­less steel pole that I might have to ditch in the fu­ture. I set­tled on what I thought was the least im­per­fect lo­ca­tion, on the taff­rail just in­side the push­pit, with braces to sta­bi­lize the pole. I bought a 9ft 6in long, 2in ID pol­ished Sched­ule 40 alu­minum pole for $60 from a lo­cal metal fab­ri­ca­tor, and sourced the mount­ing plate and sup­port brack­ets from Garhauer Ma­rine. Then there was the is­sue of in­stalling the electrics that came with the unit—the con­troller that reg­u­lates the power sup­ply from the tur­bine, the dump load re­sis­tor that ab­sorbs ex­cess cur­rent once the bat­ter­ies are full, and the in­line stop switch that can be used to turn off the gen­er­a­tor when de­sired. I had no bulk­head space in the cock­pit locker for these, so I lam­i­nated a ply­wood plate onto the in­side of the hull to hold the con­troller and re­sis­tor, while the stop switch is ac­ces­si­ble from the head com­part­ment.

Su­per­wind’s wiring di­a­gram was straight­for­ward, call­ing for 40A fuses or break­ers in the pos­i­tive ca­bles from the stop switch to the con­troller and from the con­troller to the bat­ter­ies. Al­though I could have just about have got­ten away with 10AWG ca­ble, I opted to spend a lit­tle more on 8AWG ca­ble to elim­i­nate volt­age drop.

Fi­nal as­sem­bly of the tur­bine did not take long; all fas­ten­ers were sup­plied and the in­struc­tions were ex­plicit. Wait­ing for a wind­less day, we con­nected the tur­bine as­sem­bly to the pole, bolted on the blades and raised the pole into po­si­tion. Af­ter dou­ble-check­ing all the power con­nec­tions and tight­en­ing all the mount­ings one last time, I flicked on the cir­cuit break­ers to find—noth­ing. It would be another 48 hours be­fore there was enough wind to even turn the blades. Not much hap­pens be­low 10 knots, but I’ve seen as much as 7 amps with wind speeds in the high teens. At time of writ­ing the unit had only been in ser­vice a lit­tle over a week, so a more de­tailed eval­u­a­tion will have to wait. I can say, how­ever, that the Su­per­wind is in­deed won­der­fully quiet and vi­bra­tion-free and has been keep­ing up with the de­mands of the fridge.

All in all this was a sat­is­fy­ing project, eas­ily within the scope of any­one who is rea­son­ably handy (and not afraid to to drill holes in their boat). My next step is to in­stall a 100W so­lar panel on each of the lifelines aft, and see how that wind/so­lar com­bi­na­tion works over the re­main­der of the sum­mer. s

I mounted a panel in­side the cock­pit locker for the elec­tri­cal in­stal­la­tion, leav­ing room for a so­lar con­troller to be added

The tur­bine as­sem­bly slips into the pole and is se­cured by two screws. At 25lb, it’s a solid piece of gear

The 2 ½ in clamps were too big for the 2in pole, so I lined them with ⅛ in neo­prene

The base plate fit­ted al­most per­fectly; I routed the 8AWG wire through a Seav­iew ca­ble gland

The se­cret to the whis­per-quiet op­er­a­tion is in the tu­ber­cules on the blades that in­ter­rupt wind flow

The en­gi­neer­ing of the Ger­man­made tur­bine is im­pres­sive. The sway bar fits in­side a Del­rin bush­ing

It took only a few min­utes to as­sem­ble the blades, and then bolt the as­sem­bly onto the tur­bine

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