The most common form of hydrogen extraction is steam reforming, according to the U.S. Department of Energy. Basically, water is heated to high temperatures (roughly 1,000 degrees Celsius) using methane, which reacts with the hydrogen and carbon monoxide. The carbon monoxide is emitted as a greenhouse gas while the hydrogen is then cultivated for use.
This is a more expensive version of extraction but is also the cleanest. An electrical current is run through an enclosed body of water (for example, not a lake). This separates oxygen from the hydrogen in the water and causes power. The main drawback has been it takes more power to create the hydrogen than what is actually produced.
Scientists at the University of Chicago first discovered that pond scum's atoms could be split in the 1930s and produce hydrogen but only in short bursts. It was not until 1999 to 2000 that researchers at the National Renewable Energy Lab, along with University of California at Berkeley professor Tasios Melis, found that by taking the sulfur and oxygen out of the pond scum they could make hydrogen more abundant. However, this process is still being developed
