Power generation
03 December 2017
WT
When sailing (with no engine use) for days on end the battery state of charge becomes a pre-occupation. Powering all the instruments (plotter, wind, depth, speed), VHF radio, AIS, lights, SSB radio, fresh water pump, Auto Pilot, Fridge, charging of Sat phone & iPads etc 24 hours a day, not to mention running the water maker for a couple of hours a day, takes a lot of power so the batteries need to be monitored and charged accordingly.
On Krabat we have six large solar panels mounted on the Bimini which, on bright sunny days (and provided they are not in shadow from the sails, radar etc), produce the bulk of our needs but, of course, they are only producing during the day time and, at this Latitude, that is 12 hours a day.
The solar panels are supplemented by a hydro-generator (a device hung on the back of the boat with a propeller in the water) to produce power by the action of the boat moving through the water. It however, produces much less charging current than the solar but itâs big advantage is that it produces 24/7 so is great at keeping on top of things especially at night.
Between them, these two systems are generally capable of keeping up with our demands however what I didnât expect was quite so much floating seaweed and this of course gets wrapped around the hydro-generator propeller rendering it ineffective (and also causing excessive vibration). I therefore have to lift it out of the water and clear the weed on a regular basis which is OK during the day but too risky at night so if there is a lot of weed at night I cannot deploy it at all. We therefore have no battery charging at night so the batteries become pretty depleted by morning time. If this happens then we hope for a bright day so the solar panels can recover them to full/nearly full charge. On a dull day there maybe insufficient charge and I have to resort to running the engine for an hour or so but, so far, I have only had to do that once.