Iberdrola helps to protect the environment through efficient CO2 use

#environmental sustainability #innovation #nature

This project, led by Iberdrola and approved by the European Commission, seeks to demonstrate the feasibility of capturing CO2 from natural gas combustion to reduce macrofouling, the fouling process that occurs in combined cycle power plant cooling circuits.


Macrofouling is the fouling of power plant cooling systems caused by molluscs such as mussels, clams, polychaetes and barnacles. The larvae of these organisms are fixed on these structures and, as they grow, cause the systems to clog, thus preventing the water circulation needed for the correct operation of the facilities.

These larvae are deposited in areas that are difficult to access in the cooling circuits, where they find continuous nutrient replenishment (from the continuous flow of a large amount of water), a favourable environment (with a local temperature increase of a few degrees that fosters its growth) and protection against larger predators.

The most widely used method to reduce these larvae is based on the use of chlorine and its derivatives — sodium hypochlorite —. Nevertheless, its use raises doubts derived from the real impact of chlorine discharges on the waters affected.

True to its commitment to innovation and reducing the environmental impact from its activities, the Iberdrola group has been analysing the best way to control macrofouling for several years. The result of these analyses has identified the conditions required to control it, as well as the possibility of using CO2 to slow its growth, also estimating the amount needed to do this.


The Iberdrola group, in collaboration with a consortium of six other Spanish companies, developed the CO2 Nota Formare project between 2014 and 2017 to study the feasibility of using a natural inhibitor that prevents the deposit of larvae from mussels and other living organisms in cooling circuits of the combined cycle power plants.

This natural inhibitor is CO2, reused as a by-product from other industrial processes to locally produce a moderate pH decrease that encourages the mussel larvae to find another place that is more favourable for their development. Therefore, while reusing unwanted waste from other industrial processes at the same time, the use of chlorinated chemicals in cooling circuits is also avoided.

The CO2Formare project phases will be implemented at the Castellón IV combined cycle power plant.#RRSSThe CO2Formare project phases will be implemented at the Castellón IV combined cycle power plant.

The new method also enables optimisation of the dosing process: a device has been developed that enables the online identification and counting of mussel larvae in a water stream, meaning that continuous and/or preventive CO2 dosing is not required. It is only used when it is detected that there is a higher concentration of mussel larvae in the circuit.

Another aspect of this method is that it is innocuous for mussels and other marine species since it does not alter their metabolism or biological structure; it only creates an uncomfortable environment that encourages the mussel larvae to move to another place to settle and grow.


To see this initiative first hand Edward Rubin, a member of the Intergovernmental Panel on Climate Change (IPCC), visited the Castellón IV combined cycle plant, where Iberdrola has been developing the project. The IPCC and former vice president of the United States Al Gore received the 2007 Nobel Peace Prize for their work on climate change issues.

Edward Rubin observes a CO2 diffuser used in the CO2Formare project.Edward Rubin observes a CO2 diffuser used in the CO2Formare project.

CO2Formare has been a complete success, having achieved better-than-expected results initially that vouch for the system, the methodology and the technology employed. The company is now examining the possibility of extending its use to the rest of its thermal power stations in Europe.

A total of four million euros has been invested into the project, of which the Iberdrola group contributed 40% as a coordinating partner and owner of the Castellón facilities to demonstrate the project and to validate the pilot tests.

The project has also received funding from the European Union through the LIFE+ call, aimed at supporting technology demonstration projects that contribute to fulfilling community environmental objectives.


 CO2 Nota Formare project final report (Spanish version)

 R&D in our businesses