Technology is starting to let humanity harness wind and solar energy. But using alternative energies continues to be problematic because of the high cost and difficulty of converting and storing the power into energy that can be used at a later time.
To power households using intermittent sources, one possible avenue is to feed electricity produced by solar or wind energy systems into electrolyzers in the home. These devices use catalysts to drive a chemical reaction that converts electricity into chemical energy by splitting water into hydrogen and oxygen fuels. These can be stored until needed, when they can be re-converted to electricity.
In research published in Science Magazine on April 5, two chemists at the University of Calgary say they have found a way to turn water into hydrogen fuel at a thousandth of the cost of current methods using everyday materials.
Catalysts are typically made from rare and expensive metals, such as ruthenium and iridium, which can cost more than $1,000 a gram.
Beers lead to rust
Over beers one evening, chemists Simon Trudel and Curtis Berlinguette decided to look for a new catalyst made of a mixture of metals. The new material they eventually developed costs pennies a gram and is made from common compounds like iron oxide, commonly called rust, with a dash of other metals like nickel and cobalt.
“Our method effectively translates to every metal in the periodic table,” Berlinguette told CBC News.
Unlike the crystalline structure of the pricey metals currently used, the research published in Science reported that this new method uses materials in a disordered, less organized or “amorphous” structure that create gaps called “defects.” It’s those defects that the chemists believe make their compound more reactive and therefore better catalysts.
Jack Brouwer, associate director of the University of California, Irvine’s National Fuel Cell Research Center, said other catalysts that are similarly aimed at improving water electrolysis have been discovered and advanced in recent years. The most significant finding from the Science paper, he says, is the technique the researchers have advanced that can accurately control the catalyst metal composition in a way that other techniques cannot.
“I don’t want people to think that if you engineer a catalyst well that now you have a net energy output from water. No, no, no,” said Brouwer, who was not involved in the University of Calgary research. “The basic thing is water is the product, not the fuel. No matter how good the catalyst, you still need a lot of energy. Nature doesn’t provide us hydrogen in the form of fuel, it provides us the product.”
Brouwer said the catalytic properties the researchers demonstrate in their findings are attractive and show promising initial performance compared to much more expensive catalysts. If the University of Calgary catalysts can be manufactured cheaply in the right form factor for direct use, there is commercialization potential.
Beer fridge battery
The Calgary chemists have formed a spin-off company, FireWater Fuel to commercialize their patented technology for use in electrolyzers. They hope to make their device the size of a beer fridge with the ability to deliver electricity for household use. An electrolyzer that size should be able to generate the electricity needs of a household with a couple of kilograms of hydrogen a day and a few liters of water.
Such a unit would cost under $10,000 and could be ready for testing by 2015.
“If they can lower the cost significantly and have a commercial quality and scalability, then it could be very important,” said Ed Denhoff, president and CEO of the Canadian Hydrogen and Fuel Cell Association in Vancouver. “Wind particularly needs storage, and reducing the costs of electrolysis makes current technology solutions even more commercial.”