Besides holding a PhD in physics, Bob has also studied economics and international relations. In Paris, he found the ideal place to combine those disciplines and put them into practice: research on nuclear energy. That was the start of an impressive career for him in the US and elsewhere in the field of energy and climate change.  

One of the topics he is currently working on is green hydrogen, a climate-neutrally produced fuel, or ‘energy carrier’ in Bob's terminology. Together with SEVEN colleague Frenk van Harreveld, he is taking part in the Hy-SUCCESS consortium, which starts in late 2024 and will research the economic, legal, political and socio-cultural drivers as well as stumbling blocks in the application of green hydrogen. One of their many questions is whether hydrogen, like oil and gas, could better be produced centrally and distributed over several main large production sites across the rest of the world, or decentrally and on a much smaller scale.  

In search of the ideal solution 

Bob's role in this is to search for the ideal solution using, among other tools, integrated assessment models, with which he provides scenarios to the Intergovernmental Panel on Climate Change (IPCC). Bob: ‘Should we start producing green hydrogen at the cheapest location, where there is a lot of solar energy, for example? Or does that not outweigh the additional transportation costs and possible geopolitical problems ? Should you therefore just start producing decentrally, close to those who will consume green hydrogen?’ 

The big question, of course, is how to balance all these different factors. Bob: ‘With an integrated assessment model you can answer sub-questions but then you’re only halfway there. Besides this kind of techno-economic model, you also need the social sciences to find out, for example, whether people want to live next to large or small hydrogen production facilities, whether these facilities are sufficiently safe and whether they’re thought to be safe enough.’  

He relativizes the recent renewed interest in green hydrogen, calling it the ‘third wave’, because the two previous waves of popularity did not lead to large-scale production and consumption. But he believes green hydrogen now really seems to have been given the green light. For instance, it is estimated that by 2050, 5% of our total energy needs could come directly from hydrogen. It’s therefore all the more important to carefully consider the potential downsides of hydrogen. 

Explosion risk and unwanted interactions  

Bob sees a real task for him and his colleagues to pierce through hypes, to provide a rebuttal when new technologies are once again presented in far too rosy terms. Bob: ‘It’s up to SEVEN to highlight all aspects, including those of renewable energy sources – both the positive and negative.’ 

For example, like many other gases, if hydrogen accumulates in high concentrations or under high pressure, it can explode if it comes in contact with oxygen. He refers to 2011, when the Fukushima nuclear power plant was badly damaged following an earthquake off the coast of Japan measuring 9 on the Richter scale. The heat in the reactors ran so high that water molecules split into hydrogen and oxygen, after which the two gases accumulated and caused the reactor buildings to explode. 

To Bob's great regret, an interesting research proposal he and his colleagues made on the possible impact of hydrogen on the atmosphere has not yet been accepted. Since gases always leak, no matter how carefully they are stored, a certain amount of hydrogen will escape into the air. In theory, high concentrations of hydrogen in the atmosphere could potentially slow down the decomposition processes of greenhouse gases such as methane, resulting in their remaining in the atmosphere longer and thus indirectly contributing to climate change. Such processes need to be thoroughly investigated to increase our knowledge of them. 

Unexpected side effects of hydropower  

Hydropower plants, which already produce about 13% of European electricity, may also have unexpected climate effects. Bob: ‘The large amounts of biomass that may accumulate in some reservoirs decompose and can subsequently emit CO2 and methane. Estimates on the extent of those emissions vary enormously; some studies call the emissions negligible, while others estimate that under certain conditions they could be comparable to those from certain gas-fired industrial plants.’ 

These kinds of unwelcome effects are just another indication of how complicated the energy transition is. Bob: ‘As scientists, we should above all remain as neutral and realistic as possible and certainly not let ourselves be hyped!’

Modest role 

Asked about his aims within SEVEN, Bob says he believes there should be specific professorships that are fully dedicated to climate change and the energy transition. And also that a fully-fledged institute will eventually be needed, as well as a physical place where scientists can meet. Bob: ‘In science, unfortunately, we are often still too stratified in the classical disciplines, while climate and sustainability issues clearly transcend faculties. So actually (and I am now sketching a vision of the future) you will ultimately need to have a large institute for this, perhaps the size of half a faculty.’ 

The question naturally arises: what impact will a new institute and new professorships have on the climate? Don't we already have enough knowledge and isn't now the time to act? A very valid question, Bob agrees, and largely correct, although in his opinion we still do not have sufficient knowledge to meet the EU goal of being climate neutral by 2050 and achieving negative greenhouse gas emissions after that year. 

Bob: ‘Our scientists have a modest role to play. Our job is simply to generate knowledge and provide education. We won’t build hydrogen plants ourselves, that’s not the business we’re in, but we can offer valuable insights and thus contribute to setting up a hydrogen economy in the best possible way.’ 

Elles Tukker