HOW MUCH POWER DO YOU NEED?

When installing any generating equipment on the boat, it pays to do your sums first. Work out how much power you consume at anchor and under way in a kind of power “budget.” There are the obvious things, like fridges, plotters and interior lights. But remember navigation lights at night, watermakers, pumps and “invisible” consumers such as gas alarms, engine monitors, always-on entertainment systems. If you have hydraulics or electric winches on the boat, make sure you include a hefty margin in case of emergency. If you plan to use air conditioning, it’s unlikely that renewable power sources will be able to cover demand, so you’ll need to think about a diesel genset or fuel cell.

Then look at the type of sailing you’re planning to do: what is your average boat speed and do you expect to be doing plenty of upwind sailing, or are you sticking to tradewind routes? Finally, take account of any other generating capacity you have on board: solar, hydrogenerator and good old-fashioned engine power.

It is really worth putting the time in here, so you come out of this process with a clear and accurate idea of how much power you need to generate.