It was 5 a.m. on Wednesday morning when I heard the pitter-patter of rain on deck above our bed. The prediction of precipitation had finally come to fruition and the day would be rainy and cloudy until the early evening when the sun finally made a warm and glorious appearance.
This was actually only our first full day of rain since April and our second cloudy day in a row. But due to the lack of sun and wind, Yahtzee’s house batteries had dipped too low for comfort by the time I crawled out of bed an hour or two later. So, for the first time since leaving our permanent slip a year earlier, I fired up the engine at anchor to charge the house batteries.
Getting and using power aboard a cruising boat is always a challenge, and it is tackled in numerous ways by boaters. In the quest for a perfect solution — of which there is none — I’m often asked about how we get and use power aboard Yahtzee. So here’s a simple rundown on how we live a mostly self-sufficient life while underway.
How do you make power?
Aboard Yahtzee we make power to charge our batteries in four ways: the first is by being plugged into a dock, which runs our battery charger and AC outlets. Off the dock we make our own power through our engine’s alternator, two 80-watt solar panels, and/or our wind generator. The engine is mostly used to charge the batteries when we are motoring somewhere, and the latter two are what we rely on while at anchor — which we are most of the time.
It is a regular occurrence while in a marina or anchorage when someone stops by to chat with me about our solar array and wind generator. They ask how each of them does in providing us with power and I tell them the simple truth — when there’s sun, the solar panels work great, and when there’s wind, the wind generator works great. In general, though, the solar is more effective than the wind for charging.
How that breaks down for us is that in the sunshine of the late spring, summer and early fall, we can sit at anchor for days on end with full batteries that are being constantly topped off by the solar panels and supplemented by the wind generator. When the wind is stronger and the days are shorter and cloudier in the late fall, winter and early spring, it’s the opposite; our wind generator does most of the charging and is supplemented by the solar panels.
The problem that led to our need to run the engine at anchor this week was a perfect storm of four issues: we hadn’t been plugged into a dock in nearly two weeks; we didn’t have enough consistent sunshine at a peak time of day to get a proper solar charge for two straight days; we hadn’t motored enough to get a proper charge from the alternator; and there hadn’t been enough wind to provide a charge through our wind generator.
How do you use power?
How much power used aboard a boat varies widely. Yahtzee isn’t a power-hungry vessel and we keep it that way on purpose. The single biggest draw from our house batteries is our refrigerator.
We’ve cruised without a refrigerator before in the Bahamas and lived without one in Ethiopia, so we’re well aware that it can be done. But for a family of four, we need to be able to keep our food (and beer) cold.
Similar to our solar and wind charging systems, the amount of time the refrigerator gets run depends on the seasons. In the heat of summer we run it a lot more than in the cooler days of winter. Which means that it balances out, because when we are getting more sun for charging, we’re running the fridge more. And when we’re getting less sun, our need to run it is decreased.
The second biggest power draw aboard Yahtzee is our inverter. The inverter converts DC (battery) power to AC power, which allows us to charge the computer and a few other electronics. We have to use this while at anchor and we run it maybe an hour or two per day.
One of the best things we did to decrease our power consumption aboard was to change our old incandescent interior lights to LED. When we did that, the amount of power we spent on lighting the boat dropped dramatically. Now we can have nearly every light on the boat illuminated (though we never do) and the batteries will barely move. LED lights are flat out incredible.
Living a self-sufficient life
It’s easy to take power consumption for granted when we’re constantly plugged into the grid. But when we rely on our own sources of charging to keep our lights and fridge running — in essence, to keep our house working — we have to be constantly aware of what’s on and for how long. Over time it has become a natural habit to use less power.
When I think about it, the fact that Wednesday was our first time in a year to use the engine solely for charging is quite remarkable. And it gives me great relief to know that we don’t often rely on burning an expensive fossil fuel such as diesel to give ourselves power. That I can live with.