By Michael Landspersky, TÜV SÜD Industrie Service
The EU’s 2020 Hydrogen Strategy describes actions to create a clean hydrogen economy. In the long term, the strategy relies predominantly on green hydrogen produced with electricity from renewable sources (P2H2). The EU plans to install electrolysers with a capacity of at least 6 GW by 2024, which could produce up to one million tonnes of green hydrogen.
But what sustainability criteria must hydrogen fulfil to be marketed as green hydrogen? How can producers and traders provide their customers with proof of the emission reductions achieved throughout the hydrogen value chain? So far, there is no harmonised and internationally valid definition for green hydrogen and its marketing. In addition to the electricity used for electrolysis, further factors need to be evaluated for their carbon footprint, such as water and wastewater treatment as well as the transport of the hydrogen. Since only a few regions in Europe have dedicated hydrogen pipelines, up to now hydrogen has been mostly transported by truck.
Currently, only partial areas of application of green hydrogen are regulated by the EU. The transport sector, for example, is governed by the rules of the Renewable Energy Directive 2018/2001/EU (RED II), but it will be developed further by the EU to extend the application of clear requirements to the energy, steel, and chemical industries in the future. These developments are thus relevant for all economic operators engaged in hydrogen production, distribution, and use. Nevertheless, distributors and manufacturers should not wait for the EU to pass its rules and standards. Voluntary certification schemes already enable economic operators to provide clear proof of the carbon footprint of their hydrogen.
Mass-balance approach to keep track of emissions
The GreenHydrogen certificate is based on the TÜV SÜD CMS 70 ‘Generation of Green Hydrogen’ standard. According to this, green hydrogen must reduce greenhouse gas emissions by at least 70% compared to the reference value for biofuels – including production and distribution as well as transport to the customer or fuelling station. In GreenHydrogen certification, the emissions caused by hydrogen transport are calculated using the mass-balance approach. This means that green and conventional hydrogen can be mixed in the distribution chain. Thus, the certificate does not require any additional infrastructure.
GreenHydrogen certification also considers the origin of the energy and the type of feedstock used in hydrogen production. Certifiable methods include electrolysis of both water and brines. The electricity used must be generated from renewables such as wind, solar or hydro power plants, or by steam reforming of biomethane or by pyrolysis (gasification) and catalytic inline reforming in waste incineration plants.
Case study: PEM electrolyser
To document the environmental friendliness of its 6 MW PEM electrolyser, an operator commissioned TÜV SÜD to conduct certification in accordance with the GreenHydrogen standard. The proton-exchange membrane (PEM) method produces hydrogen for fuel cells and heating purposes. The electrolyser stacks generate green hydrogen using electricity from wind power and hydropower. This hydrogen is first purified and dried and partially fed into the existing gas grid. However, since the hydrogen is primarily intended for the mobility sector, most of it is transported in truck trailers to nearby hydrogen filling stations.
TÜV SÜD analysed the entire value chain from production to cleaning, compression, filling, and transport, and determined the emission value at 15 gCO2eq/MJH2 – almost 50% below the required limit (28.2 gCO2eq/MJH2). The operator was thus able to use the GreenHydrogen certificate as proof of its achievement of over 80% in emission reduction compared to conventional hydrogen.
Conclusion
Until the EU finalises its own harmonised rules and standards, voluntary certification schemes offer transparency and advantages for sales. With TÜV SÜD’s GreenHydrogen certificate, manufacturers raise their brand profile and prove that their hydrogen reduces emissions along the entire value chain. They are thus well prepared for future EU requirements and regulations.
* Opening image | Dreamstime.com
