TECHNICAL: NOVEL GREEN POWER

Sam Fortescue looks at the latest technology for renewable energy afloat

- Sam Fortescue

As the rest of the world grapples with decarbonisation, the sailing community is benefitting from the various technical developments made in other sectors. It is now simpler to harvest and store power on board than ever before – no bad thing when you consider how many power-hungry gadgets fill a modern cruising yacht. From Nespresso machines to electric winches, sailing consumers are reaping the rewards of the efficient electricity generation.

The core of renewable energy generation for boats remains wind, solar and hydrogeneration, but the last two of these are developing rapidly. Meanwhile hydrogen is continuing to make inroads into the sailing market.

It all comes down to how much power you need: a kilowatt-hour over the day to run the fridge and electronics (83Ah), or 50 times that for induction cooking, air-con and even electric propulsion.

Wind remains an important part of the mix, capable of adding up to 500Wh on a blustery day, but here the technology is more mature. There may be small incremental improvements – quieter blades or more efficient power transfer. ‘There is not going to be a silver bullet in respect of renewable generation on yachts because the physics tell us that the existing technology is already very efficient,’ says Peter Anderson, MD of Eclectic Energy. ‘For example, our D400 wind generator converts 36% of the kinetic energy in a 12-knot wind stream into electricity. The theoretical maximum (Betz Limit) is 59%, and the latest multi-megawatt commercial turbines achieve around 40% efficiency due to their scale.’