Green Hydrogen Plants. Processing and impacts

From an environmental point of view, we analyze new hydrogen plants with renewable energies. As in any more or less novel project, we must know how it will be processed before the MITECO or before the respective Autonomous Communities, as well as the main impacts from an environmental point of view.

What are Green Hydrogen Plants

It is well known that hydrogen is the fuel of the future and is the most abundant element in the universe. Its current global demand is more than 70 million tons per year and is expected to increase. Current demand is almost entirely supplied by fossil fuels, which causes the emission of huge amounts of carbon dioxide per year.

To avoid this impact, a non-polluting alternative has been created, the so-called green hydrogen, obtained through the electrolysis of water. Since this process requires electricity, it will be generated in a renewable way (wind or solar energy), resulting in emission-free hydrogen being obtained in the process.

The environmental procedure for promoting a Green Hydrogen Generation Plant

• These types of facilities will require a request for approval of Integrated Environmental Authorization because they are included in the heading 4.2, chemical installations for the manufacture of inorganic chemicals, from Real Legislative Decree 1/2016, of December 16, approving the consolidated text of the Integrated Pollution Prevention and Control Act.
• These projects are also included in Annex I, group 5, heading .2º.i., chemical industry, production of inorganic chemicals, of the Law 21/2013, of December 9, on environmental assessment.
• We must look at the way in which energy is obtained, so we must also attend to the Law 21/2013, of December 9, on environmental assessment where in its annex I, group 3. Energy industry indicates the need for submission in these cases:
  • Heading i) Installations for the use of wind force for energy production (wind farms) that have 50 or more wind turbines. Or that they have more than 30 MW or that are less than 2 km from another wind farm in operation, under construction, with administrative authorization or with environmental impact statement.
  • Heading j) Installations for the production of electrical energy from solar energy intended for sale to the network. That they are not located on the roofs or roofs of existing buildings and that occupy more than 100 ha of surface.

Environmental Impacts of Green Hydrogen Plants

Let's now review the main environmental impacts that this energy can pose.

• Noise and vibration production. The electrolysis process is silent, since it is an electrochemical reaction. It has no moving parts, so noise and vibration emissions in electrolysis equipment are zero. Conversely, compressors are needed if they produce noises and vibrations. This should be where greater emphasis is placed on the measures to be taken.
• Emissions and immissions. These plants do not generate NOx, CO, particles or Total Organic Carbon, so there is no need to apply preventive measures in this regard.
• Discharges and water consumption. This type of plant generates waste water from the purification of water used for the electrolysis process, which is expected to increase its conductivity considerably, so it is expected that preventive measures will be aimed at controlling this factor. A consumption of 50% is estimated, that is, half of the input water will be returned, although with a higher degree of conductivity.
• Waste generation. The main wastes generated in this type of plant are all those related to the treatment of water from the electrolysis equipment, they will mainly be reverse osmosis membranes, water pretreatment cartridges, ion exchange resins, etc.
• Conditions affecting fauna and flora. They will be those inherent to the installation of renewable energy (Wind power or solar) associated with the Green Hydrogen plant.

Cover photo: Geopura