In photosynthesis, plants take sunlight, wrestle hydrogen from h20 and make ATP, their power source. When we create alcohol or other synthetic fuels from plants we are really harvesting the energy from sunlight that freed the hydrogen from inside the plants. To make alcohol from corn we have to plow the fields, lay down fertilizer and insecticides, plant the seed, and harvest the corn - all of which takes a lot of energy and emits carbon.
What if we could just skip the plant and get the energy straight from the sun?
That's what Nanoptek is doing.
Nanoptek has a special catalyst to free hydrogen from water in the presence of sunlight.
Why use this process instead of photovoltaics? One of the advantages is the ability to store the energy for use later. A farm of Nanoptek's harvesters could create hydrogen all day and store it for burning in turbines at night or peak demand. This gives great flexibility to the power-grid. The hydrogen gas could through serious chemistry be used to create liquid fuels similar to diesel.
What remains to be seen is whether the economics will work, but their recent announce is exciting to see.