One out of 10 posts came out some time ago amazing predictions of the future of scientists and writers. It was missing that of Jules Verne, who in his 1874 novel "The Mysterious Island" wrote: "One day water will be used as fuel. The molecules of hydrogen and oxygen that compose it can provide an infinite supply of energy and light, more than can never make coal. And when the coal reserves are exhausted, we will use water for heat."
Do you realize how much time has passed? A century and a half and we are still here, with fossil fuels (which however are, it seems, in the pipeline). Will the mammoth "hybrid" gas pipeline project developed by Portugal, Spain and France help?
BarMar: from fossils to hydrogen
The governments of Spain, Portugal and France they will build the so-called Bar Mar, a gas pipeline running from Barcelona to Marseille. It is a replacement for the initial design, MidCat, a gas pipeline intended to cross France to supply gas to the northern countries. After the change of route on the French side, a new three-way agreement was born for the creation of a gas pipeline which will initially transport normal fossil gas, but will then move on to transport hydrogen. The end of the works is not expected before 2026, according to French sources say which may need to reach 2030.
Hydrogen can still revolutionize the world of energy: it is a non-polluting gas, and this makes it a key element in the fight against climate change, because its potential to reduce CO₂ emissions could make a big difference. However, it must be transformed into a usable form before energy can be extracted. And its current generation process may require more effort than its combustion offers in return.

All the colors of hydrogen
Hydrogen can be obtained in several ways and falls into several categories:
- Gray hydrogen, produced by the reaction of natural gas and water vapor, makes up the majority of currently existing hydrogen. The main disadvantage of using gray hydrogen is the emission of CO₂ into the atmosphere at the time of production: this nullifies any environmental benefit.
- The blue hydrogen it is obtained as gray hydrogen but the CO₂ produced is then captured.
- Green hydrogen or low-emission hydrogen is obtained by electrolysis of water, i.e. by breaking down the water molecule with renewable electricity.
The green and blue colors are the only ones that meet the low emission requirements. However, other colors are also included in the hydrogen palette, such as pink hydrogen, produced by the electrolysis of water from nuclear energy, or gold hydrogen, created using organic waste with CO₂ capture.
A pipeline to kick-start it all
Once produced, hydrogen must be transported to the place where it will be consumed. Ideally, its production should be located as close as possible to where it will be used, but this is not always possible. For this reason, hydrogen is transported over short distances a bit like butane: in pressure vessels transported by truck.
For greater distances it is more efficient to have a gas pipeline, indeed: a network of pipelines. In the short term, it will be possible to take advantage of the existing natural gas distribution network (in a process known as blending). However, to transport gases with high concentrations of hydrogen, the pipes of a gas pipeline will have to be modified.
That's not all: the low density of hydrogen makes twice the number of compressor stations necessary for gas: therefore the distance between compressor stations would be half that for natural gas.
BarMar pipeline: big questions for Spain and Portugal
Whether the BarMar pipeline can eventually be used to transport hydrogen depends on multiple factors. In a sense, a pipeline like this could be compared to an electric cable: an infrastructure created to transport energy generated by another source.
This hydrogen pipeline would then function as a vector to export the renewable energies created in the peninsula: solar and wind energy. Therefore, BarMar will only really make sense if Spain and Portugal are able to produce enough renewable hydrogen to meet domestic demand and have a surplus to export to France.
Increasing hydrogen production means increasing electricity production: this in turn means more high-voltage power lines to carry it. Existing plants are not enough: we need more solar plants, more wind turbines and perhaps even more nuclear power.
And it is immediately Nimby
The needs I have listed make the project complex: apart from its technical feasibility, the greatest fear is its unpopularity with Portuguese, Spanish and French citizens. If this pipeline project is indeed part of a robust acceleration on renewables, there will also be a future for hydrogen.
If not, it will simply be a replacement for the MidCat, that pipeline that the French (compatriots of Jules Verne, to come full circle) never wanted.