So-called Power-to-X (PtX) technologies are seen as a good way of reducing greenhouse gas emissions because their potential for storing energy could stabilise the electricity grid, which is needed to further develop renewable energies. However, German environmental groups BUND and the Öko-Institut have criticised the technology. EURACTIV Germany reports.
Artificially produced gases, liquids and chemicals that store energy – so-called Power-to-X technologies (PtX) – are often referred to as the key to the energy transition.
However, a position paper published on Monday (29 June) by the German environmental NGO BUND and the research institute Öko-Institut noted that PtX technologies are not ‘necessarily’ more environmentally-friendly than coal mining.
If the electricity required to power the energy-intensive PtX process does not entirely make use of renewable energies, carbon emissions would be high.
The carbon footprint of PtX technologies “could even be much worse than with fossil fuels such as natural gas or diesel,” according to BUND chairman Ernst-Christoph Stolper.
The power source is essential when it comes to PtX because the process is so energy-intensive as it is based on artificially-produced hydrogen.
The PtX process can be carried out by steam reforming, which is based on natural gas and releases a lot of CO2.
The process can also be carried out through electrolysis, which, despite being emissions-free, still requires a lot of electricity.
PtX substances should only be produced using renewables
If one relies on PtX as an energy source in future power grids, it needs to be ensured that renewable energies are used, according to the authors of the position paper.
The origins of the required CO2 also need to be clarified. Only in combination with CO2 can hydrogen be processed into widely-used methane or e-fuels.
However, if CO2 is not extracted from coal, oil or gas, alternatives are limited.
Wood is one of the primary sources, but its cultivation requires large areas. The position paper concluded that it is necessary to ensure that only sustainable biomaterials are used.
Alternatively, carbon dioxide can be cut off from the air, but the technology has not yet sufficiently matured, according to the paper’s authors.
“The technology will only be available in practice in the medium term and as a comparatively expensive option,” the authors of the paper admitted.
“Let’s not make the same mistakes as with biofuels”
It would also be possible to use CO2 that emanates from industrial processes. However, climate protection groups warn that it would give an economic value to emissions that should be reduced.
This would counter-balance the European Emissions Trading System (EU ETS), according to Peter Kasten of the Öko-Institut.
“We should not make the same mistakes with PtX as with biofuels. Only if it is ensured from the outset that PtX reduces greenhouse gases should they be promoted,” Kasten concluded.
This would require political instruments to help fund PtX technologies that would provide the industry with planning security for corresponding investments.
According to the position paper, another important aspect is ‘sustainability monitoring’ when importing PtX products.
In all likelihood, Germany will have to import hydrogen or processed e-fuels, as the expansion of renewable energies in Germany is limited due to there being a lack of space.
In the context of monitoring, it must then be verified whether, for example, there is sufficient water and sustainable land available in the exporting country.
In other words, it needs to be made sure that the exporting country can operate PtX technologies on a large scale.