Electrics – Living on Wind, Sun and Hydro

“She’s using nothing, she’s polluting nothing. And the wind is still there, after she’s passed, for the next man to use” (Anon. Clipper Ship Vega https://www.facebook.com/groups/576928642405766/permalink/1147321648699793/)

Since Luckyfish was launched in 2012, she has never been connected to the grid. There is no need for a shore-power socket and no petrol or diesel generator aboard. The boat is powered fully by energy from the sun, the wind and her speed through the water – hydroelectric energy*. Living this way is one of the biggest kick’s I get out of cruising. It is almost as rewarding as sailing itself.

Energy storage comprises 3 x 105Ah deep cycle calcium lead acid batteries in the port hull and 2 x 105Ah deep cycle calcium lead acid batteries in the starboard hull, totaling 525Ah. Both battery banks are isolated. A sixth battery is located at the forward end of the port engine housing. It is isolated from the rest of the system and starts the two Yamaha 9.9HP outboards and powers the windlass.

Prior to the Atlantic crossing, I added a 12V EchoTec watermaker, Broadband 4G radar, 12″ chart plotter and AIS transponder to her existing load, which consisted mainly of refrigerator, basic nav instruments and lights. It was pretty obvious that we would have an energy and storage deficit, however, with ‘good management’ of demands, we sailed across the Atlantic utilising all these items of equipment to the extent we needed, with just 270W of installed solar capacity.

Solar charge is fed first through a normal battery isolation switch, re-purposed to send the charge to both battery banks, or just the port or starboard one. Solar controllers are installed on both battery banks and on the engine start battery which is tied into the port side charging lead.

So, just what does ‘good management’ translate to? Firstly, we prioritised our energy needs. For example, during the daytime in full sun with both banks topped off (normally by noon to 2pm) and everyone wanting a shower, I run the water maker for 30 minutes and produce about 30 litres of fresh water. This takes the port battery bank down to 50 or 60% or so and leaves enough time to restore the charge with the remaining hours of sunlight.

At night time, running the radar becomes the priority, as well as the chartplotter, AIS and nav lights, in that order. I regard the biggest risk we face at sea is colliding with another ship, although it is extremely unlikely. So our objective each day is to finish the daylight hours with a fully charged starboard battery bank, which runs the nav instruments including the radar. Without a hydro generator we can not run the chartplotter and radar for long, so we turn it on every 20 or 30 minutes and scan the horizon at various ranges before shutting down again. Standby mode uses just as much power so we have to shut it down. With the 4G technology, the power (and time) required to start-up the unit is minimal, compared to the old magnetron technology. It has proved to be an awesome unit.

None of this is ideal. We would like to be able to produce more freshwater, particularly the girls whose regular hair washes seem to gobble amounts that would make most salty cruisers cry, and, on passage, we would like to run the radar all night, especially with a range alarm, or two, set. At times the 12V fridge needs to be turned off at night when the starboard side nav bank don’t get a full charge.

Since the Atlantic crossing we have added a Watt & Sea hydrogenerator (see the video here ) The addition of this unit has made us fully self sufficient for all our energy needs while on passage, meaning we can run what we need, for as long as we want it.

The unit we installed is 12V, 970mm shaft length, 300W (suits the speed profile for our boat when passage making we average 5.5 to 7 knots, and our energy needs), 240mm prop. Here is a link to the spec sheet from the manufacturer, which is very useful

Our next step is to fit a Rutland 1200 wind generator to the top of the main mast. This is the highest possible location on Luckyfish and therefore the most suited to a wind powered device.

The purpose of the hydrogenerator is primarily to maintain charge at night time on passages to allow continuous use of the radar and chartplotter. The wind generator’s primary purpose is to provide charge on cloudy days at anchor, although it will contribute some charge on passages as well. This should result in a robust system that provides oodles of power >95% of the time. All without the need for fossil fuels or marina’s.

Click here for a spreadsheet containing estimated Energy Consumption over a 24 hour period for all the devices on Luckyfish. The consumption is balanced against our existing battery bank of 525Ah and highlights some improvements that can still be made. Ideally we should have sufficient storage to run all our systems for 24 hours or longer using 50% of our real world battery capacity. Real world battery capacity is likely 85% of the rated capacity due to temperature and age effects. The spreadsheet shows we need another 105Ah of storage and need to have an option to link both battery banks. Thanks to Robert Johnson of the Wharram ‘Tolfea’ for providing the basis of the spreadsheet.

*All renewable energy systems in use today are powered, ultimately, by the sun. We should think of wind and hydro energy as solar power. Arguably tidal energy is partial lunar power, but that is an exception. Geothermal energy, while not solar derived, is also not renewable over timescales meaningful to our current needs.

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