Reaching a global, carbon-neutral economy will require a significant level of renewable penetration – up to 85% in the world’s future electricity mix. Most political and scientific scenarios acknowledge that renewable electricity will have to be complemented by power-to gas (PTG) technologies to provide fully sustainable seasonal storage to the energy system and achieve complete decarbonisation of global economies with a focus on electro-intensive sectors, transport and industry. In 2019, PTG is entering the selective club of “2050 clean energy technologies”, which is the portfolio of clean technologies needed for a carbon-neutral economy and to keep the world below the 1.5°C global warming milestone.

This has not gone unnoticed by energy companies. In February 2019, the first large-scale solar-to-hydrogen facility was inaugurated by Siemens and Dubai Electricity and Water Authority (DEWA) at the outdoor testing facilities of the R&D Centre of Mohammed bin Rashid Al Maktoum Solar Park in Dubai, which – once its 5 GW capacity is completed by 2030 – will be the largest solar plant in the world.

The solar to hydrogen revolution is also coming – fast – to Europe. In November 2019, leading utility ENGIE signed a deal with the Durance, Luberon, Verdon urban area (DLVA) and Air Liquide to develop the ‘HyGreen Provence’ project. The project will combine the production of 1,300 GWh of solar electricity in the south of France, together with the production of renewable hydrogen on an industrial scale through water electrolysis.

Challenges

Despite these positive signals, the rising debate about a ‘hydrogen economy’ needs to be addressed with infinite precaution. Not all ‘hydrogen’ varieties are in line with the Paris Agreement: synthetic gases produced from conventional oil and gas technologies are still a significant factor of CO2 emissions; its potential ‘green’ colour will rely heavily on the maturity of carbon capture and storage (CCS) which has not yet reached market parity and still has to prove its competitiveness, unlike renewable energy solutions. However, even if the world’s future energy mix snapshot won’t be 100% electric, it can be 100% renewable – with solar energy being the key to any contributing technology, and this includes hydrogen.

The cost-efficient production of renewable-based hydrogen will require significant volumes of cheap electricity – which is a win-win combination for economies with a high penetration of solar energy. Solar energy is quickly becoming the cheapest source of power generation. With huge, untapped global potential, the technology will grow very quickly from 1% in 2015; according to Lappeenranta-Lahti University of Technology, Finland (LUT), solar could cover up to 69% of the world’s electricity mix by 2050 in a 100% renewable-based energy system. (Figure 9)