Within the framework of projects submitted to the Environmental Impact Assessment System (“SEIA” for its Spanish acronym), the Environmental Assessment Service (“SEA” for its Spanish acronym) published the technical criteria to be presented by project owners in the description of green hydrogen production and storage projects.
The referred guidelines address the electrolytic process of green hydrogen production - commonly known as water electrolysis[1] -, detailing the main supplies for the green hydrogen production process, and the characteristics of the storage and distribution projects for this type of fuel.
Green hydrogen is projected as a raw material for the production of other derivatives, such as refining petroleum-based fuels, ammonia production and green methanol production.
The following is a summary of the main contents of the guidelines:
Analysis of SEIA submission
From the review of the typologies listed in Article 10 of Law No. 19,300 and Article 3 of the SEIA Regulations, it can be observed that there is no specific typology for green hydrogen production, storage or transportation projects.
Therefore, these projects shall be submitted to the SEIA when parts of the project or its activities fall within the existing typologies. Some typologies that could be applicable are:
- Letter a), in consideration to the water use of these projects.
- Letter b), if high voltage transmission lines and their substations are considered.
- Letter c), if power generation plants higher than 3 MW for the supply of clean and renewable electric energy (such as photovoltaic, wind or others), are considered.
- Letter ñ.1) if the production, disposal or reuse of toxic substances to be carried out in a semester or more and in an amount equal to or greater than 10,000 kg/day, is considered.
- Letter ñ.3) if the production, disposal or reuse of flammable substances to be carried out during a semester or more, with a monthly frequency or greater and in an amount equal to or greater than 80,000 kg/day, is considered.
- Letter ñ.4) if the production, disposal or reuse of corrosive substances to be carried out during one semester or more, with a monthly periodicity or more and in an amount equal to or greater than 120,000 kg/day, is considered.
- Letter ñ.5), if the transportation by land of toxic, explosive, flammable, corrosive or reactive substances to be carried out during a semester or more and in an amount equal to or greater than four hundred tons per day (400 tons/day) is considered.
- Letter o.6), if submarine pipelines are considered.
- Letter p), if it is contemplated the execution of works, programs or activities in an area under official protection.
- Letter s), if it is contemplated the execution of works or activities that physically or chemically alter a wetland located totally or partially within the urban limits.
I. Description of green hydrogen production projects
It is essential that the project description chapter is sufficiently detailed and disaggregated to allow the reader, both public authorities and the community, to comprehensively understand the project and identify its potential environmental impacts.
The main supplies related to projects that produce green hydrogen shall be described and presented. The guidelines provide a more detailed description of the following supplies:
a. Water: To produce green hydrogen through the electrolysis process, water is required (approximately 10 tons of water to produce 1 ton of hydrogen).
For the provision of water, at least the following should be considered:
- Quantity required per unit of time;
- Source of supply (type, georeferenced location of collection point, mode of supply);
- Destination;
- Type of transport for loading and unloading water;
- If there is a nearby population using the same water source for consumption, indicate the volume of consumption at the water collection point.
In the event that the project considers accumulation and water supply reservoirs, the facilities to be used shall be described[2].
b. Electrical energy: Electrical energy from renewable sources is required. The energy supply should be described according to the following:
- Quantity required;
- Form of supply (type, georeferenced location of the connection point to the power grid, mode of supply);
- In the case of requiring generators, the power of each generator, type of fuel and operating regime shall be detailed;
- Destination.
II. Green hydrogen storage and transportation
One of the main challenges of storage projects is the necessary infrastructure, given that, having a low volumetric energy density, it requires larger volume tanks at high pressures[3].
The hazard classification of green hydrogen, according to the Chilean Safety Standard (“Norma Chilena”) NCh382:2021, corresponds to class 2 (gases), division 2.1 (flammable gases), both for compressed hydrogen and refrigerated liquid hydrogen.
The transportation of green hydrogen, either as compressed gas or cryogenic liquid, is usually conducted by land (truck, rail or other) or by sea (ship) to its distribution points. It may also require the construction of a pipeline or the use of existing gas networks.
The guidelines, as its name suggests, is a brief introduction to green hydrogen projects and establishes the minimum contents to be included in the "Project Description" chapter of a green hydrogen production and/or storage project to be submitted to SEIA, either as an Environmental Impact Declaration or an Environmental Impact Study.
[1] Process that uses electricity to split the water molecule (H20) into hydrogen (H2) and oxygen (O2). It uses water as raw material, which, regardless of the source, must be previously treated, generally by a reverse osmosis and deionized process, and then transported to the electrolyzer, where the water is electrolyzed using renewable energies.
[2] At least the following shall be described:
- All units comprising the supply and storage system;
- Number of tanks;
- Dimensions of the reservoirs;
- Destination or use of the water;
- Layout of the location of the reservoirs next to the other equipment;
- In case where the effluent from any of the sewage treatment plants is reused, it shall be indicated.
[3] Currently, hydrogen can be stored as a compressed gas in high-pressure cylinders or as a cryogenic liquid (-252 ºC) in specially designed insulated tanks.