All inboard engine equipped boats require to operate the electronic and start the engine. For additional electric loads like radios, winches, refrigerators, VHF communication, navigation instruments and fans, low voltage DC electric supply is sufficient.
Modern, larger and well equipped boats also for living on board, require higher electric power, with 220/110 Volt supply, to operate the electric oven, electric water boiler, water maker, air conditioning, dish washer, vacuum cleaner, battery charger and some other equipment. These electric power requirements are normally higher when the boats are not in operation.
Conventional generator sets are available in many sizes for these requirements. They require additional space and installation, additional maintenance and they run continuously whenever the high AC voltage is required, with high engine speed, mostly 3000/3600 rpm. In the increasingly overcrowded bays, the continuous or longer running generator sets cause more and more protests from the neighbour's boats. Optional retails list prices of such equipment installed in the boat range from between 3 to 4 times of the Genset unit price. In the boats below 40' lengths it is also difficult to find an additional space with good enough service accessibility for this purpose.