Reinout is the founder of Victron Energy Systems, the Holland-based developer of the WhisperGen generator, a DC generator that rewrites the rules for onboard energy. The generator is powered by a Stirling engine, an external combustion engine patented in 1816. Using efficient diesel burners to maintain a high temperature at the cylinder heads, the engine repeatedly heats and cools a mass of nitrogen gas within four cylinders. The expansion and contraction of the gas propels a piston in each cylinder. The generator weighs 198 pounds and occupies about 1.7 cubic feet. It has few moving parts, resulting in very little noise or vibration (and no oil to change). Producing minimal exhaust emissions and no oily exhaust fumes, it can be left to automatically tend to your charging needs for days at a time. When the WhisperGen is also used to heat water and warm the boat, the engine's efficiency (the amount of power produced for fuel burned) is as high as 95 percent, and operating costs are less than 5 cents per kilowatt-hour (based on fuel costs of $1.50 per gallon).