Believe it or not, long-distance cruising by sailboat requires electrical energy. At least on our boat it does. By today’s standards, we have most of the electronic systems that you could find on a cruising sailboat, including radar, chartplotter, GPS, AIS, autopilot, wind/depth/speed instruments and VHF radio. We also have a few extra goodies such as our SSB, stereo, laptop computer, refrigerator and water pressure system. Add in the bilge pumps, lighting and a few other odds and ends, and we have a fairly high demand for 12VDC electricity; between 90 and 100Ah/day.
As far as battery capacity is concerned, we like to spend as much time as possible anchored and away from marinas, which means we don’t get to ‘plug in’ for days at a time. To make this possible, we upgraded the factory DC system to give us more capacity and greater charging capability while running our engine. The downside is added weight, but we feel this compromise is OK. On our first voyage to the Bahamas, we carried a Honda EU2000 generator in our starboard locker. These generators are quite popular with cruisers in the south and we found ours to be a valuable asset. It is easy to use and generates enough AC power to charge our house bank back up in less than 2 hours. The generator was fairly quiet, but we tried to avoid using it in crowded anchorages. However, I was less reluctant to use it when neighbouring boats had their own gensets and wind generators whirring away.
Over the past year or so, Mary and I researched alternative energy sources for Strathspey including wind generators and solar panels. There are obvious advantages to both wind and solar, but in the end, we chose solar because it is quiet and we have a convenient location to mount the PV panels. So, in April 2012, we had two solar panels mounted over our bimini and I wired them up to our DC system. We installed two Solarland 85Watt panels which feed through a Solar Boost 152iX MPPT charge controller (Blue Sky Energy) to our DC positive bus. Over the summer, we learned that the panels provide enough power to handle our DC energy needs, even on cloudy days. Sticking our necks way out, we sold our Honda EU2000 generator. In the end, we reduced our dependency on gasoline and reduced the on-board weight by about 30lbs
Our summer experience in lake Ontario didn’t hold up in the south, where the days are shorter and the refrigerator runs a lot more steadily. So, before our next trip, we’re adding two more solar panels and putting that 30lb generator back in the starboard locker.
A drawing of our 12DC system is in this schematic Here are the details: