Thoughts on the Prospects of Renewable Hydrogen

In the last two years or so, there has been increasing interest in hydrogen as an energy source in Australia and around the world. Notably, this is not the first time that hydrogen has caught our collective interest. Most recently, the 2000s saw a substantial investment in hydrogen research, development, and demonstration around the world. Prior to that, the oil crises of the 1970s also stimulated significant investment in hydrogen, and earlier still, the literature on hydrogen was not lacking. And yet, the hydrogen economy is still an idea only.
So what, if anything, might be different this time?
This is an important question that we all need to ask, and for which the author can only give two potential answers. First, our need to make dramatic reductions in greenhouse gas (GHG) emissions has become more pressing since these previous waves of interest. Second, renewable energy is considerably more affordable now than it was before, and it has consistently outperformed expectations in terms of cost reductions by even its strongest supporters.
While this dramatic and ongoing reduction in the cost of renewables is very promising, our need to achieve substantial GHG emission reductions is the crucial challenge. Moreover, meeting this challenge needs to be achieved with as little adverse social and economic impact as possible.
When considering what role hydrogen might play, we should first think carefully about the massive scale and complexity of our global energy system, and the typical prices of the major energy commodities. This provides insights into what opportunities hydrogen may have. Considering a temperate country with a small population like Australia, we see that domestic natural gas and transport fuel markets are comparable to and even larger than the electricity market on an energy basis.