Scientists at the Department of Energy’s SLAC National Accelerator Laboratory have developed a new catalyst for splitting water. Here’s why this is big news:
One of the great strengths of renewable energy is their consistency and predictability. Yes, wind and solar have periods when they’re not generating power (with some exceptions like certain solar thermal designs), but the sun is available for a set amount of time every day, and wind blows in predictable patterns where turbines are placed. These predictable patterns make it easy to balance the grid, and to calculate how many units are needed to meet demand.
But here’s a little secret. All sources of power are intermittent. There is no power plant, coal, nuclear, or gas, that is available 100 percent of the time. The electrical grid is built with this in mind.
A well functioning coal plant, will not be available 44 days of the year.
For nuclear, it’s 36 days, as well as 39 days for refueling every 17 months or so.
Wind power has a failure rate of only 2 percent, and units rarely go down all at once.
The reality is that when we really start investing in renewable energy, we don’t see shortages, we see cases of too much power being generated. Of course there’s no such thing as “too much power”, provided you have ways to use it or store it. There are a LOT of ways to store power for the grid, using a wide variety of techniques and forms of energy. For today, though, we’re focused on one in particular
Hydrogen can be used to generate power in a couple different ways. First, it can be used in a combustion engine, in much the same way as gasoline, natural gas, and biofuels. Second, it can be used in a fuel cell, which uses a non-combustive reaction to combine hydrogen and oxygen to generate energy. The obstacle to using hydrogen as a power source or a method of power storage is in getting the hydrogen. Hydrogen has a number of other uses – particularly in the fossil fuel industry, and its primary source is currently fossil fuels, which makes it a non-sustainable form of energy storage. That said, splitting water into its component elements via an electrical current is an old trick. It hasn’t been used much, because it tends to lose more energy than other forms of power storage, but it has a few advantages, in that it requires fewer dangerous substances than battery storage, and it can be used anywhere that has water.
And that brings us back to the point of this blog post: The good folks at the National Accelerator Laboratory have developed a catalyst made from fairly common elements that allows for water to be split at about three times the speed of current electrolysis technology*. If this pans out, it will make hydrogen from water – already a potential source of power storage and transport in a world with excess renewable energy generation – into something that could be much more useful, much sooner than expected.
*correction: I originally thought this was an increase in efficiency (the article I was looking at said “three times better”), but Johnny Vector pointed out the error, and it looks like he was right. That said, when I looked into it following Johnny’s correction, I did find this work by a different team, which does indicate progress on energy efficiency as well as speed:
Water electrolysis has not yet established itself as a method for the production of hydrogen. Too much energy is lost in the process. Researchers have now doubled the efficiency of the reaction.
Only four per cent of all hydrogen produced worldwide are the result of water electrolysis. As the electrodes used in the process are not efficient enough, large-scale application is not profitable. “To date, hydrogen has been mainly obtained from fossil fuels, with large CO2 volumes being released in the process,” says Wolfgang Schuhmann. “If we succeeded in obtaining hydrogen by using electrolysis instead, it would be a huge step towards climate-friendly energy conversion. For this purpose, we could utilise surplus electricity, for example generated by wind power.”
These are two separate catalyst designs, but the overall trend is clear – electrolysis is becoming more viable as a means of energy storage and transport