Enel Green Power has published an article noting the successful use of 3D printing in their flagship Geyser project at Santa Barbara metallurgy labs in Cavriglia, near Arezzo, Italy.
The idea to use 3D printing to repair essential components was spawned at a roundtable discussion organised by the project Geyser team. A group of technicians and experts from the geothermal, thermal, and hydroelectric sectors gathered to discuss how to optimise the management of geothermal plants and came up with the plan.
“It all started from our curiosity and desire to use the 3D printer that we had in-house,” says Nicoletta Mazzuca, Enel Green Power’s project manager for Geyser. “We wanted to repair parts that were going to end up in landfills because they couldn’t be fixed with conventional forging techniques.”
The 3D printing machine is located in the Santa Barbara metallurgy labs, at the headquarters of Engineering and Technical Support for Enel Production, where an additive manufacturing machine with Laser Metal Deposition (or Direct Energy Deposition) technology has been available since 2019. This extremely high-tech tool can reproduce and repair various metal parts by depositing the necessary material one layer at a time.
The pilot project began when the printer was used to repair an impeller, which is an essential component of the centrifugal compressor of a geothermal plant.
The team purchased a powdered form of the material used to make the impellers (a special kind of stainless steel called 17-4 PH), followed by laser scans and the creation of the 3D model. The work was carried out by a team led by Gennaro Raniello, Head of Hydro Maintenance Support – O&M Hydro Italy at Enel Green Power, and it concluded with the first historic repair of a worn part thanks to this technology.
According to Enel, this sustainable innovation will make it possible to set in motion a cycle of reuse of materials: until now, worn impellers were simply replaced with new ones and ended up in landfills, so repairing them will also save around €70,000 ($85,000) per year.
“After a year of work, we were able to use additive manufacturing processes to repair our impellers for the first time. Not only does it give our impellers a second life, it also saves us money while respecting the environment thanks to a circularity of 100%,” added Mazzuca.
Matteo Niccolai, workshop maintenance and technical services leader – O&M Geo Italy of Enel Green Power said: “The idea of using additive manufacturing to solve one of Geo’s supply chain issues is a concrete example of the effectiveness of sharing problems and best practices transversally within the company, solving critical issues with the help of previously unseen perspectives.”