Using hydrogen as a clean, renewable source of energy could free us from fossile fuels. But hydrogen atoms don't exist alone in nature; they're always bound to another atom. Think of water, which has hydrogen and oxygen. Splitting hydrogen atoms from the oxygen takes power. And if that electricity comes from a natural gas or coal planet, well, we're just back to where we started.
But scientists say that using nuclear power could be the answer. Ibrahim Khamis, of the International Atomic Energy Agency (IAEA) in Vienna, Austria, said heat from nuclear power plants — already used to make steam that powers turbines for electricity — could be used to make hydrogen.
Nuclear power plants aready produce heat and change water to steam on a massive scale, Khamis said. They also provide the electricity to electrolyze the water. Current plants could use a low-temperature electrolysis, taking advantage of low electricity prices during the plant’s off-peak hours to produce hydrogen. Future plants could be designed specifically for making hydrogen, using a more efficient high-temperature electrolysis process. There's also research into using heat and chemicals to break down water, and you could link a power plant to that.
The IAEA has a Hydrogen Economic Evaluation Programme (HEEP) in place, with software designed to help member countries evaluate the technical and economic feasibility of hydrogen production this way.
While this sounds promising — there are 435 nuclear plants operating in the world today — there are downsides. One is building more nuclear power plants in the first place. The Fukushima nuclear disaster made many nations wary of doing that, and some countries, such as Germany, are abandoning nuclear energy altogether.
Then there is the issue of water use. Most electrolysis assumes fresh water, and that's not always a renewable resource. Seawater would be better, but nuclear power plants aren't designed to use it as a coolant. Nuclear power plants currently use far less water than irrigation or even households (the power industry accounts some 3 percent of fresh water use, according to the United States Geological Survey) but that would change if a sizable portion of the water were being converted to hydrogen.
Either way, there is still a lot of work to be done on the economics of this proposal – the cost of energy to extract hydrogen has been one of the (many) stumbling blocks to adopting it as a fuel. Using nuclear power plants might offer a way around that – and cut greenhouse gas emissions as well.
Photo: The Gundremmingen nuclear power plant in Germany. Credit: Felix Konig / Wikimedia Commons