Nanoptek, a startup based in Maynard, MA, has developed a new way to make hydrogen from water using solar energy. The company says that its process is cheap enough to compete with the cheapest approaches used now, which strip hydrogen from natural gas, and it has the further advantage of releasing no carbon dioxide.If this pans out - obviously a big if - it's a huge breakthrough, and not just for the obvious off-grid applications and the not-so-obvious water-purification ones . Inexpensive, direct, sunlight-to-hydrogen conversion means there's an effective way to chemically store solar power for future use. So what, you ask? Well, fossil fuels are nothing but chemically stored solar power; this could be a practical way to replace them.
Nanoptek, which has been developing the new technology in part with grants from NASA and the Department of Energy (DOE), recently completed its first venture-capital round, raising $4.7 million that it will use to install its first pilot plant. The technology uses titania, a cheap and abundant material, to capture energy from sunlight. The absorbed energy releases electrons, which split water to make hydrogen. Other researchers have used titania to split water in the past, but Nanoptek researchers found a way to modify titania to absorb more sunlight, which makes the process much cheaper and more efficient, says John Guerra, the company's founder and CEO.
Cool possibilities, there.
 Apparently, their process doesn't require pure water. Seawater, fresh water, even graywater - as long as you can pump it over their catalyst, you get hydrogen.