Imagine a zero-emission fuel that can be squeezed out of polluted water using a process powered by renewable energy. We may be closer to this reality than you think.
The company HyperSolar just completed the prototype phase for a new solar-powered system it says can "split" hydrogen -- that's the zero-emission fuel -- from dirty water, leaving cleaner water behind.
If you're new to the water-splitting topic this may sound a bit gimmicky, but it's for real. Similar technologies are under development by researchers around the globe. MIT and Lawrence Berkeley National Laboratory provide two among many examples in the U.S. And the U.S. Navy is testing a fuel-producing device based on seawater.
However, referring to hydrogen as a "zero-emission" fuel under present circumstances is somewhat disingenuous. There are no tailpipe emissions when hydrogen is used in a fuel cell vehicle, for example, but the main source of hydrogen was (and still is) natural gas.
Using an electrical current to split water is another way to get hydrogen. But that process is not viable in a fossil fuel economy, at least not on a large scale. It requires a tremendous amount of electricity.
In the U.S., coal and natural gas still dominate the electricity production landscape, so that's a no-go in terms of climate impacts. The local impacts of fossil fuel extraction also make a case against sourcing hydrogen from natural gas on a large scale.
Now that the age of renewable energy is gathering steam, the hydrogen-sourcing picture looks much brighter.
Wind and solar now provide a pathway for powering the water-splitting process on a large scale without relying on the fossil fuel chain. In addition, the intermittent nature of wind and solar power has motivated the search for large-scale energy storage solutions, and hydrogen fits the bill.
In Europe, for example, policymakers are looking at wind-powered, water-splitting systems that use the existing natural gas distribution network to store and transport hydrogen.
HyperSolar is a good example of a next-generation solution. The HyperSolar system was engineered specifically to be deployed in untreated water. The result is a twofer: a zero-emission fuel and cleaner water.
That's an important advantage in the future energy market. In the electric vehicle sector, for example, batteries have already established a strong foothold. The water treatment aspect of next-generation hydrogen production could provide an added value that helps fuel cell electric vehicles to carve out a niche.
In a solar-based system like HyperSolar's, the water splitting system consists of a solar cell submerged directly in water. When exposed to sunlight, the charge generated by the solar cell results in a flurry of bubbles that are visible to the naked eye.
Here's a general description of from the National Renewable Energy Laboratory:
"The cleanest way to produce hydrogen is by using sunlight to directly split water into hydrogen and oxygen. Multijunction cell technology developed by the photovoltaic industry is being used for photoelectrochemical (PEC) light harvesting systems that generate sufficient voltage to split water and are stable in a water/electrolyte environment."
A high-voltage solar cell that mimics photosynthesis is a second critical element in the system.
Earlier this year, TriplePundit profiled HyperSolar and described these two aspects of the technology in detail, arriving at this conclusion:
"The combination of these two elements provide a distinctive economic advantage. But is it enough to relaunch the hydrogen economy? Only time will tell."
The U.S. lags behind Europe and Japan in the hydrogen economy, but it looks like that is about to change. Earlier this year the Energy Department described a "deep decarbonization" concept for the U.S. economy, and last month it issued a request for public input:
The U.S. Department of Energy (DOE) has issued a request for information (RFI) to gather feedback on H2 @ Scale, which is a concept to enable wide-scale deployment of hydrogen to deeply decarbonize the U.S. electricity generation, transportation, and industrial sectors.
Another potential power source for large-scale, non-fossil hydrogen production consists of reclaimed waste heat from nuclear power plants and other industrial operations.
As for the shale gas angle, the Energy Department makes it clear that continuing to produce hydrogen from shale gas would only count toward deep decarbonization if it is coupled with carbon capture.
If the cost of carbon capture is excessive, that could make renewable technologies like the HyperSolar system more competitive in the marketplace.
The next steps for HyperSolar involve scaling up, so stay tuned.
Image (screenshot): courtesy of Hypersolar via YouTube.
Tina writes frequently for TriplePundit and other websites, with a focus on military, government and corporate sustainability, clean tech research and emerging energy technologies. She is a former Deputy Director of Public Affairs of the New York City Department of Environmental Protection, and author of books and articles on recycling and other conservation themes. She is currently Deputy Director of Public Information for the County of Union, New Jersey. Views expressed here are her own and do not necessarily reflect agency policy.