It’s now clear that we have the technology we need to run a completely decarbonized electricity generation system. South Australia is the world leader generating more than 50 per cent of its energy from renewable sources, and aiming for 100 per cent renewables by 2030.
The unit cost of renewables is now well below that of carbon-based generation (and nuclear). The remaining big question regarding the economics of the transition is the cost of storage, taking account of the variable nature of solar PV and wind.
As I’ve pointed out before, any reversible process that uses energy is a potential storage technology – that’s true of batteries, pumped hydro, flywheels, stored heat and many more. But hydrogen is a particularly appealing storage technology, because it offers the potential to decarbonize major industrial processes.
Electricity can be used to separate water into hydrogen and oxygen (electrolysis). The process can be reversed by combustion, and for a long time the main interest in hydrogen was as a replacement fuel for motor vehicles. But with progress in electric vehicles, that’s become less important.
Interest now is focused on hydrogen as a replacement for metallurgical coal in steelmaking and for natural gas (methane) across the board.
The central technology for steel is direct reduction (DRI), using hydrogen to combine with the oxygen in iron oxide (ore) leaving metallic iron. The HYBRIT (Hydrogen Breakthrough Ironmaking Technology) initiative has just started operations at a pilot plant in Sweden.
Hydrogen can also replace methane in just about all its applications, from home heating to industrial uses. However, this will require a substantial investment in hydrogen-safe polyethylene pipes and new equipment. Also, while not as bad for the climate as methane, hydrogen leakage into the atmosphere is still a potentially significant problem.
It it were up to the Australian political class, particularly at the national level, none of this would matter. We are stuck in a pattern of denial and delay. But things are much more promising in the EU and other developed countries. Biden is promising some fairly radical action, which would reinforce existing trends in the US, but of course we have to wait to see whether Trump loses, and if so, whether he concedes. We still have a chance to stabilise the global climate and avoid catastrophic damage.
fn1. But the EU is not far behind with 40 per cent renewables (an average that is pushed down by Eastern European countries like Poland and Czechia).
fn2. Hydrogen can also be produced from lignite, an idea currently being pushed here in Australia . But this process produces CO2 as a byproduct. In the absence of a viable technology for carbon capture and storage, which will never happen, it’s worse than useless as far as the climate is concerned. Hopefully, that fact will ensure that such projects