Mention hydrogen and a legion of critics will outline the reasons why the gas will likely never be a major energy source.
But it doesn't mean that researchers still aren't working on these problems. And the latest idea comes from Rice University, where scientists have found that buckyballs-- molecular balls made up of 60 or more carbon atoms--can store hydrogen quite well.
The molecules can store around 8 percent of their weight in hydrogen at room temperature, Rice found. The federal government, meanwhile, has set a goal of finding materials that can store 6 percent of its weight in hydrogen.
The density of the hydrogen is about the same density that hydrogen would be held at the center of Jupiter.
"Based on our calculations, it appears that some buckyballs are capable of holding volumes of hydrogen so dense as to be almost metallic," said Boris Yakobson, professor of mechanical engineering and materials science at Rice, in a prepared statement.
An ability to store more hydrogen would likely translate into a longer driving range for hydrogen-powered forklifts or vehicles. Conceivably, the buckyballs could be reduced to a powder and sprinkled into a fuel tank: a chemical or physical agent could then be added to release the hydrogen at a steady rate from its carbon cage.
A decent storage medium is one of the chief challenges to hydrogen. Hydrogen can't be sent down ordinary pipelines--a lot of the gas could escape as well as damage the pipe. Compressing the gas and storing it in tanks takes energy and results in bulky storage. Many are experimenting with fixing the gas in metals. Metal prices, however, are escalating. Some others are working on ways to fix hydrogen in chemical powders.
Others are touting microbes and low-cost electrodes.
Hydrogen storage would also help buckyballs start to live up to their commercial promise. Discovered more than 20 years ago (through the work of now deceased Rice professor and Nobel winner Richard Smalley), buckyballs helped put nanotechnology on the map. Many thought the molecules would get adopted by industry. Instead, industry has largely gravitated toward the nanotube, which is a tube-shaped molecule made most of the time from carbon.
As a fuel source, hydrogen has some great characteristics. It's the most abundant element in the universe and in combustion engine it leaves water as a byproduct. Now, the problems: producing it requires electricity or large amounts of heat, production often results in ornate amounts of carbon dioxide, and the infrastructure of filling stations doesn't exist. Hydrogen car prototypes cost about a billion.
Still, advocates say you have to think big and futuristic. Naysayers have been wrong before and the interesting lab results can't be denied. The waste heat from nuclear plants could be harnessed to produce hydrogen. One idea being floated about is building a wave farm in the open ocean that would provide electricity for hydrogen production. The gas could then be compressed into a liquid in an undersea chamber.