The big electrical loads on the boat are the refer, the watermaker, and the autopilot. We spent a lot of time putting together the most energy efficient systems we could find. The lighting loads are minimized by our fantastic new LunaSea LED lights. They put out more light for way less power than the old incandescent or Cold Cathode fluorescents. The LED anchor and navigation lights are especially important in limiting our energy use because they’re on for long periods.
We have two major ways to make the electricity.
The primary source is this large-frame alternator on the front of the motor. It’s as big as your head. The external regulator keeps the charging current high for much longer than an automotive alternator, and temperature regulation keeps the alternator and the batteries from overheating.
Nancy absorbs solar energy and re-radiates happiness rays. The solar panels absorb solar energy and turn it into electrical energy.
Each pair of panels is wired in series, then the panel sets are wired in parallel into the MPPT tracking controller at the top of the picture. The controller makes sure the batteries get the voltage and current they need to maximize their performance. The black Xantrex box under the controller is a 600W True Sine Wave inverter. It’s big enough to run our sewing machines, battery chargers, and other small loads. It’s not big enough to run a vacuum cleaner. Xantrex products are crap, but there are few options in this size.
The electricity is stored in the house battery bank for use later. These are super 8D AGM batteries, 270 AH each for 540 AH total. Not huge, but good.
Moving the power around takes some pretty big copper. The red blob on the left is the primary battery disconnect. The black rectangle above is a relay to parallel the house and engine starting battery during charging. The two smaller rectangles below are the breakers for the main power distribution and the anchor windlass. The jumble on the right is a calibrated shunt that we use, with a Mastervolt computerized monitor, to measure and track the amount of power left in the battery.
The solar panels can be quickly stowed in place or deployed flat using a telescoping stainless tubing fitting mounted on the front and aft ends of the panels. We’ll leave them up most of the time. So far we’ve seen 240W from the 400W panels. We’ll see more as we head south. The panels don’t gimbal because we will always be at anchor, so the boat will move; and we’ll be south, so the sun will be overhead, mostly, on average.