Many owners are disappointed by the output of their wind generators
Each year our boats get more complex, with more gadgets that rely on electricity, yet technology also means that power can be more easily and reliably supplied than ever before. Granted, a large battery bank that’s carefully monitored to avoid damage through discharging it below 50 per cent is still a critical component, but for many boats reliance on the main engine – or a diesel generator – is now a thing of the past.
The cost of solar panels has plunged over the past few years, to the point at which it’s possible to festoon the boat with them – in particular over the bimini (indeed I’ve seen some boats with a hard sun cover made of solar panels) and also on the coach roof. In the past the latter was often shunned, as the panels will often be shaded, but the reduced price of panels now means it’s economically feasible to place them here.
The recent style of hydrogenerator is first-class at generating power at sea
Wind generators are often fitted by cruisers, but have a couple of serious drawbacks. Firstly, their moving parts mean they are not as reliable in the long term as solar panels. More importantly, most cruising routes are downwind and a key purpose of a good anchorage or harbours is to provide good shelter from the wind. This means wind generators are rarely exposed to enough breeze to provide more than a fraction of their rated output. Some owners attempt to counter this by placing the unit as high up the rig as possible – I’ve seen some mounted on the masthead – but that creates a nightmare for maintenance.
A more expensive, but arguably more useful, solution is a hydrogenerator. These are mounted either on the stern of the boat, from where they can be swung down into the water when needed, or mounted directly under the hull ready for use at any time. Output ranges from around 100W at 5 knots to as high as 500W at 9 knots of boat speed, depending on model. This is far in excess of all but the biggest wind generators and will easily power all systems, including watermakers, while under way. This also means you can arrive at your destination with batteries already fully charged, which in turn means the solar only has to keep them topped up.