Maximum comfort and low fuel consumption? It can be done!

Sailing around the world while consuming very little energy. This is the philosophy with which a pair of American sailors have been sailing for years aboard Celeste, a 40-foot Sparkman&Stephens built in 1986 pushing themselves everywhere, even to the most extreme altitudes in Alaska. What is striking about their experience is what they state about on-board consumption: 120 amps per hour without sacrificing comfort.

This, of course, does not mean that the American pair has a 120-amp-hour battery bank on board: otherwise they have Two AGM batteries for starting and on-board services (Rolls Battery Engineering S12-230, Rolls battery Engineering is a leading manufacturer of batterie North American lead-acid) capable of producing up to 460 amperes per hour and chosen by the couple before setting out on one of their Alaskan sailings.

Keeping consumption so low requires some tricks in the use of batteries and the main energy “eaters” on board. To make batteries last a long time for example, the key is to never let them fall below 75 percent charge before fully recharging them to prevent damage. This means constantly monitoring the state of charge.

On board modern boats, a major source of energy consumption is refrigeration systems. Aboard the 40-foot S&S, the refrigerator consumes little energy, however, how? When the compressor is running, it initially consumes 4 amps, which is gradually reduced to 3, 2, and 1 (a 12-volt system is used). The compressor is an Engel equipped with pistons powered through low-friction magnetic fields that, once driven, need virtually no additional energy. The freezer is not huge in size so the cooling plate has a larger surface area than that of the refrigerator, which is always loaded from the top so that cold air is not lost, and it is also kept full at all times so that food that is already cold helps keep everything at temperature.

Another big “eater” of energy is the watermaker, but living aboard, it is indispensable. On board Celest they installed Katadyn’s smallest model, the PowerSurvivor 40E, which is capable of producing up to 5.5 liters of water per hour while consuming 4 amps, thus fitting perfectly into the “onboard energy budget” of 120 amps per hour. Even in Alaska on a sunny day, the desalinator manages to be powered only by the energy produced by solar panels (200 watts of rigid polycrystalline solar panels that in relation to surface area yield better than flexible ones. On a sunny day in Alaska they can produce up to 1o ampere ). And you should not be intimidated by maintenance, because it is quite simple.

On board Celeste,hot water is not a problem either. The pump for water pressure is small (about 3.5 liters per minute) and the bilge pump for emptying the showers consumes 2 amps but runs only for a few seconds. For a full shower, opening and closing the water as needed, they consume about 7 liters each.

For sailors who also sail in winter, the onboard heating is another “energy eater.” An Espar has been installed aboard Celeste, which heats up well and quickly but is only used when the engine is running. For this, a Refleks diesel kerosene heater was also installed, which does not need any kind of electrical consumption and has as its only defect that it cannot heat the whole boat but only a small room.

As for interior lighting and sidelights, LED lights are used everywhere, of course: with the whole boat lights on, there is only one ampere consumption and they need to be replaced very rarely.
The onboard radar consumes when in operation 3 amps (1 amp when in standby); the chartplotter display is also LED and consumes 0.7 amps at full brightness