OK, first things first – stop picturing a car with solar panels connected to its engine. What Missouri-based inventors Matt Bellue and Ben Cooper are working on is something a little different than that. They want to take an internal combustion engine, and run it on water and solar-heated oil instead of gasoline. That engine could then be hooked up to a generator, to provide clean electricity. While that may sound a little iffy to some, Bellue and Cooper have already built a small-scale prototype.

The duo have labelled the system HydroICE, which is short for Hydro Internal Clean Engine. Here’s how they envision it working ...

To begin, mirrored parabolic solar collectors would be used to heat oil to a temperature of at least 400 to 700ºF (204 to 371ºC). This hot oil would then be injected into the cylinder chamber of the engine, just like gasoline ordinarily is. A few microdroplets of water would then also be introduced, which would turn to steam immediately upon contact with the hot oil.

The rapidly-expanding steam would serve the same purpose as exploding gas, driving the piston downward and turning the driveshaft. As the piston reached the bottom of its stroke, the spent steam and oil would exit the cylinder and be run through an oil/steam separator. They could then each be returned to their respective reservoirs, for re-use within the closed-loop system.

Hot oil would be injected into the cylinder (Fig 1/Port A), water droplets would then be introduced to that oil (Fig 2/Port B), then the resulting steam would force the piston down (Fig 3)

In order to test the technology, Bellue and Cooper have converted a 31cc 2-stroke gas engine to run as a HydroICE engine. While it isn’t clear if they’ve actually had the thing running yet, they have partnered with Missouri State University and the Missouri University of Science and Technology to develop all the necessary peripheral hardware (such as the solar collectors), and to test the engine’s efficiency.

That efficiency is currently estimated at being at least 15 percent – about the same as the maximum efficiency of existing photovoltaic panels. The technology's big advantage, however, would be price. They’re projecting that a HydroICE system would cost about a quarter of what an equivalent-output photovoltaic system would go for ... obviously, though, that’s still looking some distance down the road.

For now, they’re trying to raise research and development funds via Indiegogo. More information is available in their pitch video below.

Source: HydroICE