Sustainable hydrogen: the fourth pillar of the energy transition

Sustainable, low-carbon hydrogen is the fourth pillar of the energy transition after renewable energies, energy efficiency and electrification. In practical terms, this means that without low-carbon hydrogen, the energy transition is incomplete. Efficiency measures should be carried out, energy consumption reduced and renewables-generated electricity utilised directly in those sectors where this is feasible. These measures are enhanced by the use of low-carbon hydrogen as a potential energy source and input for industrial applications.

If electricity-based hydrogen is to help protect the climate over the long term, it must meet a number of criteria:

  • Green hydrogen: The electricity used in the production of green hydrogen must be generated from additional renewable energies. Green hydrogen will be the centrepiece of the hydrogen supply in the medium to long term. This will require a further major expansion of electricity generation from renewables in Germany, Europe and other countries.
  • Blue and turquoise hydrogen: Most of the CO2 emitted during hydrogen production from natural gas is captured and sent for long-term storage as gaseous or solid carbon. This type of low-carbon hydrogen may be of relevance in the short to medium term.
  • Grey hydrogen is produced using electricity that mainly comes from fossil fuels. Its greenhouse gas emissions are therefore relatively high compared with hydrogen produced using natural gas, so it cannot be classed as sustainable hydrogen.
  • For all colours in the hydrogen palette and all production locations, whether in Germany or abroad, ambitious sustainability standards must be applied.
  • Hydrogen should mainly be used in sectors and applications where no other decarbonisation options are available. Examples are the steel, chemicals and cement industries, aviation and shipping and as a substitute for natural gas in heat and power cogeneration.
  • In short, hydrogen is not the key to transforming the transport or heat sector. Battery electric vehicles and heat pumps are far more efficient than the use of hydrogen and hydrogen-based applications. Hydrogen can merely complement these technologies in these two sectors.
  • Hydrogen is also a comparatively costly climate change mitigation option; for that reason, more cost-effective alternatives should be deployed first.
  • Germany cannot produce more than a very small percentage of the renewables-generated electricity required for hydrogen production. We therefore need to establish international partnerships at an early stage in order to achieve hydrogen supply security for Germany.
Infographs on the topic of hydrogen (Flickr)  

Hydrogen: Information and services from the Oeko-Institut

The Oeko-Institut’s experts are engaged in a range of projects that focus on the production and sustainability of PtX materials. They provide advice to decision-makers on legislative and regulatory initiatives, analyse and assess sectors with potential for hydrogen use and conduct research on the required sustainability criteria.

Further information

Electricity-based fuels: the future of PtX

Online magazine eco@work, Issue 3/2020: Power-to-X: Why do we need PtX?