Opening up a path for solar hydrogen

| Michaela Nesvarova

Solar-hydrogen technologies could provide the sustainable energy source of the future. How do we ensure that they are used in our everyday lives? Together with experts from all over the world, UT researcher David Fernandez Rivas answers this question - in an article that made it onto the October cover of the prestigious journal Energy & Environmental Science.

Photo by: Gijs van Ouwerkerk
David Fernandez Rivas

The paper ‘Pathways to electrochemical solar-hydrogen technologies’ was published in the latest issue of the journal. It represents perspectives of over fifty scientists and government and industry representatives, with David Fernandez Rivas being the main initiator and one of the leading authors.

‘It is a polemic paper,’ says Fernandez Rivas. ‘We were very candid and tried to show that the technology is very promising, but that it certainly won’t solve all the energy problems faced by our societies.’

What are solar-hydrogen technologies? 

Photoelectrochemical solar-hydrogen technologies are able to capture and store solar energy in the form of hydrogen. The hydrogen can therefore be used whenever and wherever there is a demand for it. The technologies represent an environmentally friendly alternative to traditional fossil fuels and could be applied in transportation, energy storage or ammonia production, for example.   

‘We need to avoid the Google Glass phenomenon’

It all started two years ago when Fernandez Rivas organized a conference in Leiden, inviting members of governments, companies and scientists. The ultimate goal: to find out how to bring solar-hydrogen technologies to the market. ‘Until then, everyone focused on separate aspects, e.g. the chemistry and the environmental impact, but almost nobody tried to advance towards what society needed or could utilize. We wanted to get everyone together and discuss how we could bring this technology to people’s life – and do it fast,’ says the UT researcher.

‘We can’t just sit in our ivory towers,’ stresses Fernandez Rivas. ‘We need to reach out to all stake-holders, so we can avoid the Google Glass phenomenon. The Google Glass was a great example of a technology that was ready and functioning, but failed commercially because it was not accepted by society.’

Societal acceptance is one of the topics discussed in the paper. Are people ready to use hydrogen technologies? ‘There are some big challenges in that regard,’ answers Fernandez Rivas. ‘Hydrogen technologies are a hype but also perceived as risky because hydrogen is explosive. We need to educate society. We must openly talk about the risks and learn to live with them - like we learnt to live with coal and nuclear plants. Scientists, the industry sector, and governments need to guarantee the safety and provide the appropriate infrastructure. Nobody will agree on using a new technology if it’s not safe or if it’s too complex to use.’

The future is uncertain

According to the paper, it will take a long time before people can use solar-hydrogen technologies on a daily basis. The authors conclude that in the short-term (within 10 years) the technologies could be commercialized in several niche markets, such as space or military applications. In the long term, however, the future of solar-hydrogen technologies is very uncertain. ‘As long as fossil fuels are cheaper, most people will not pay for the “premium” cleaner options,’ points out Fernandez Rivas.

Timeline showing the possible applications of solar-hydrogen technologies. Picture used in Energy Environ. Sci., 2018, 11, 2768 

The paper therefore states that in order to deploy the technologies broadly in the energy markets, we would not only require significant technology advances, but also cost reductions, and efficient political measures, such as a CO2 tax. David Fernandez Rivas notes: ‘Sadly there are governments and companies that would prefer the business to go on as usual.’

Bringing the solution as far as possible

The UT scientist wants to contribute to a more sustainable future where solar-hydrogen technologies are more common. Besides the recently published paper, he is conducting fundamental research to understand how hydrogen bubbles behave. He co-authored a paper on the topic and the article has also been accepted for publication in Energy & Environmental Science.

‘We first need to understand the problem, but I believe it is a scientist’s responsibility to bring the solution as far as possible, which means to the companies or institutions that can valorize it most effectively,’ says Fernandez Rivas. ‘That is why the paper “Pathways to electrochemical solar-hydrogen technologies” is written in a language that is understandable and can be used not only by researchers, but also by industry and government officials.’