Most of the world will eventually be able to run entirely on renewable energy, primarily using solar power and storage. There’s a long transition towards it and it may prove politically difficult, but technically it is fairly straightforward. The parts of the world that are trickier are those that get less sunlight during the winter, right at the point when overall energy needs are at their highest.
In the global north, we need energy for heating, and renewable heat is a massive technical challenge. Efficiency and good design can reduce our needs for heating, and we’ll be able to electrify some of it. Another obvious place to start is with the existing infrastructure of the gas network. We can add biogas and gas from waste, and with some tweaks to the grid, we can also use hydrogen.
There are experiments in various places around Europe and beyond, testing ways of using more hydrogen in heating. I reported on one at Keele University recently. It can be used in transport and industry as well, and we’ll be hearing a lot more about hydrogen in future, either as gas or as fuel cells. Using renewable energy to generate that hydrogen is, hopefully, going to be one of the big stories of the 2020s.
Hydrogen is created in an electrolyser, which uses energy to split water into oxygen and hydrogen. This can be done at small scale, and in Japan some home-owners have domestic electrolyers called Ene-farms which create hydrogen for electricity. (A company in Germany has just begun marketing a domestic electrolyser as part of a whole-home energy system, and I’ll come back to them another time.)
Ideally though, we’d be adding hydrogen to the grid, rather than relying on individuals to buy and fit their own decarbonisation technologies. We’ll never get to net zero without mass technologies that reach people whether they are interested or not, whether they live in houses or apartments, and whether they rent or own.
This week I read about an idea for making that as direct as possible. Danish wind power company Orsted and hydrogen company ITM Power have jointly proposed fitting an electrolyser into an offshore wind turbine, potentially in the tower itself. It would be a wind turbine that produces gas rather than electricity.
The clean power generated by the wind turbine would be put to work immediately, with no grid losses from dispatching electricity to a hydrogen plant. Rather than connect the turbine to the power grid, you would connect it to the gas grid instead. As well as being more efficient, this could potentially be cheaper. Everything happens on the offshore platform, so there’s just the one site and that makes it easier to get permits. And hydrogen gas pipes are cheaper than high capacity power lines, so there would be a saving in the connections.
This is just a proposal at this stage. It might not come to anything. But it will be ideas like this, measures that can deliver larger scale quantities of affordable hydrogen, that will determine whether hydrogen becomes a mainstream part of the solution. Ideas like this increase the possibilities for decarbonising the gas grid. I’ll be interested to see if it happens.