In December 2019, the European Commission presented the European Green Deal, an ambitious package of measures that should ensure that the EU meets its climate goals, while enabling European citizens and businesses to benefit from a sustainable green transition.

In that sense decarbonization technologies are ramping up to mitigate the buildup of greenhouse gases and to minimize global warming. However, we know that there are some fundamental limitations with current forms of renewable energy, namely their variability over time, both short-term and seasonal, and their geographical limitations since they cannot be generated everywhere. This creates the need for an alternative.

In recent months, several European countries have defined hydrogen as one of their bets on the road to energy decarbonization, under the European Ecological Pact announced at the end of 2019. This colorless gas, especially in its green version, emerged in force and in a few months became one of the great protagonists of clean energy options for the coming decades and one of the pillars for the decarbonization of the economy. By being able to blend it into the existing natural gas pipeline network, not only it increases the use of renewable energy, but it also offers new approaches to energy storage and energy transport.

Recently announced green hydrogen national targets

Germany is currently leading the hydrogen trend in Europe, as its policies are already more developed. In June 2020, published a national hydrogen strategy consisting of 38 steps with a total cost of €9 billion focused mainly on the production of hydrogen from renewable energy resources.

After Ursula von der Leyen’s opened the way, Portugal decided to create its own National Strategy for Hydrogen (EN-H2), approved on July 30, 2020, which foresees an investment of €7 billion in a series of projects and initiatives, and with which it intends to position itself to access the respective European funds, create jobs and pave the way for decarbonization.

The targets to be met by 2030 include the creation of 50 to 100 hydrogen filling stations, 10% to 15% green hydrogen injection in natural gas networks, 2% to 5% energy consumption in the industry sector, 1% to 5% energy consumption in road transport and, 3% to 5% energy consumption in domestic maritime transport.

Spain, as mentioned in a previous blog, also wants to promote the deployment of green hydrogen as it considers it to be key to Spain achieving climate neutrality by 2050 at the latest, and so it has also approved its “Hydrogen Roadmap: a commitment to renewable hydrogen”.

Title: The EU And U.K. Have Ambitious Hydrogen Plans
Source: S&P Global

Overall the EU’s strategy, presented in July 2020, calls for setting up electrolyzer fleet of total capacity between 5 GW and 6 GW by 2025, and then another 40 GW by 2030; and to produce 1 million tonnes of decarbonized hydrogen by 2024 and 10 million tonnes by 2030.

Investments of such a scale should no doubt give a strong impetus to the development of hydrogen production, storage, and transport but, this solution sounds quite expensive, especially until carbon pricing drives a fuel switch to hydrogen, and so it remains to be seen if and when the hydrogen economy would become viable.

This means that at this early stage, projects for production and use of green hydrogen are more political than economic as government subsidies and funds are essential to get projects off the ground. Only then, economies of scale could be achieved, and private investors would be willing to place their bets on this economy.

The role of the Natural Gas sector

Also commonality all these strategies place the natural gas sector as a key driver for the effective implementation of a hydrogen economy, since it allows us to produce cheaper carbon free hydrogen and to use the existing natural gas infrastructures as a way to transport and store green hydrogen.

Blue Hydrogen

This Blue version is also expected to play its part, especially in the short-term. Eventhough it is produced from natural gas, like its grey counterpart, it has no emissions since the CO₂ is captured and stored, making its production costs just a bit higher than the cost of grey hydrogen (the cheapest version). This way blue hydrogen might work as a bridge to scale up the hydrogen market in the early stages and potentially lead to a faster decline in overall emissions.

Blending of Green Hydrogen in Natural Gas

Green hydrogen can be blended in most natural gas networks at a rate of 6% in terms of volume. This can happen in the absence of sensitive structures or installations on the customer’s premises.

So, the possibility of the transportation and storage of green hydrogen through existing natural gas pipelines is expected to play an important role on the effective implementation of a hydrogen economy as the blending of green hydrogen can defray the cost of building dedicated hydrogen pipelines during the early market development phase.

Nevertheless, adding hydrogen into natural gas pipelines raises some questions on transportation efficiency and safety in a pipeline.

Some challenges associated with blending of Green Hydrogen in Natural Gas

  • Safety concerns – safety concerns have to be considered since metallic pipelines shows a higher risk of failure, compared with plastic pipelines, particularly, higher leakage rate, in case of operation with hydrogen and compressed natural gas (HCNG) blend.
  • Flame spreading – Hydrogen burns faster than methane gas and the flame is also not bright while burning which could result in the risk of flame spread.
  • Energy density – The energy density of hydrogen is around 33% of that of natural gas’s energy density and so a 3% blend of hydrogen blend in a natural gas pipeline would reduce the energy content that the pipeline transports by around 2%. This would result in the use of greater gas volumes by end-users to meet given energy needs.
  • Product quality – Variability in the volume of hydrogen blended into the natural gas stream would have an impact on the operation of equipment designed to accommodate only a narrow range of gas mixtures. Equipment with a lower tolerance for the use of gas mixture will define the tolerance of the overall transmission network. One of the biggest constraints is expected to be in the industrial sector, where much industrial equipment has not been assessed in for hydrogen blending.
  • Smart metering – since the energy content, supplied to final end-users has to be controlled and correctly measured and since hydrogen concentration could change with time, smart metering is crucial to monitor the hydrogen percentage and to measure the effective energy content of the hydrogen and compressed natural gas flow.
  • Blend limits amongst countries – different countries have different blend limits. France has a 6% blend limit of hydrogen; for Germany between 2-8% is allowed; the UK had a blending limit of 0.5% but was increased for specific HyDeploy project to 20%. For countries like Portugal and Spain, the blend limit varies between 4% to 6%. Since natural gas is traded internationally, harmonized mixing limits between countries are important for smooth transportation.


With this in mind, and even though ultimately, they will be competitors, it seems the natural gas sector might be a low hanging fruit to a shift towards a hydrogen-based energy system.

Making sure that we can successfully blend hydrogen in the natural gas network can prove an important step towards developing a hydrogen economy, as blending avoids the significant capital cost involved in developing new transmission and distribution infrastructure separately for hydrogen, while also prolongs the useful life of the existing infrastructures and allows to reach higher levels of incorporation of renewable sources in the final consumption.

Meanwhile blue hydrogen can serve its purpose on helping us fairly faster meet the climate goals.

Matilde Loureiro | Energy Consultant

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