Everyone knows that sailboats are powered by the wind. But “powered” isn’t quite the right word. In practice, it’s just a few circumstances—mostly downwind, with somewhere between 10 and 30 knots of wind—when sailboats can travel under sailpower alone.
But even when the wind is perfect, cruising sailboats need power for things like hot water, refrigeration, lights, music, the autopilot, iPads, and much more. We have all of these things on Pineapple, so how do we power them?
The second power source comes from the earth: Fossil fuel, diesel in particular. Pineapple has a diesel engine, which, in addition to propelling the boat when there’s no wind, drives two alternators that generate electricity and charge a bank of batteries. Then we use the batteries to provide electricity for the gadgets and systems I mentioned above.
(For the nerds aboard, here’s the details: Our 80-horsepower Yanmar has two 120-amp alternators, which charge a bank of ten Group 31 gel batteries, each with 96 amp-hour capacity, for a total capacity of about 960 amp-hours.)
The diesel engine is handy, and it really can generate a lot of electricity, but I get far more excited about the third power source: Fire. Or in other words, power from the sun.
Our previous boat, Aegea, had a single solar panel that could keep up with the fridge, sometimes, or top off the batteries if we left her sit with everything switched off.
But on Pineapple, we have five solar panels that cover our ongoing power needs and generate enough surplus electricity to charge the batteries. (And again, for the nerds, that’s five Solbian flexible panels with a total theoretical output of 437 watts, or 36 amps at 12 volts.)
The panels are mounted on top of the canvas bimini awning and hard fiberglass dodger, which means you can’t even see them. The result is free, quiet, invisible power whenever the sun is out. And for cruisers like us, that’s a very big deal.
Here you can see all five panels: one on the dodger, four on the bimini.
A bit more detail on the excellent installation work, a collaboration between Liem Dao (LTD Marine, electrical) and Tom Krase (Cover Craft, canvas).
3 comments
Super happy you guys are cruising! New boat too….nice.
Hi Guys – Dud is curious re power usage – is your solar sufficient to cover the energy hogs – thinking about the following: auto pilot, refrigeration, chart plotter/radar overlay, ice maker, water maker/ inverter/keep batteries topped off? Looks like a great solution to keep the diesel consumption down. Have fun in the Sea of Cortez. Debbie
The short answer is: no, our panels don’t fully cover our electrical needs.
In good midday sun, we see 15-20A out of the panels. Our fridge and freezer each take 4.5A, but they’re only running half the time. The autopilot uses up to 10A, but only when it’s turning the rudder. The watermaker needs 15A, but we don’t run it all the time. But of course, the panels don’t do anything at night 🙂
Those are the technical details. Here are some operational realities:
– While underway, we’ve never run the engine just to charge the batteries. In other words, we always run out of wind before electricity.
– While anchored, we’ve gone a few days without running the engine. Part of this is starting with a large (880Ah) fully-charged bank, but part of it is the offset from the solar.
– In marinas, we usually don’t hook up to shore power until the third or fourth day (if we’re staying that long).
I’d love to install more solar, but we don’t have room without doing anything tacky. Maybe the next boat will have a big hard top we can fill with panels. Here’s a drool-worthy example from a big Dashew powerboat: http://www.setsail.com/fpb-78-1-solar-energy-update/