Flyer · EN — Four-page Siemens Energy flyer (© 2025) presenting the EU LIFE Blue GIS 420 kV project: the first demonstration of the economic viability of a climate-friendly 420 kV gas-insulated switchgear (GIS) completely free of fluorinated greenhouse gases (F-gases) and intentionally free of PFAS, equipped with a digital low power instrument transformer (LPIT). Clean air insulation and vacuum switching technology — both with a global warming potential (GWP) of zero — are already increasingly used in 72.5 kV and 145 kV switchgear, but until now have not been commercially available in 420 kV equipment; SF6, used in almost all high-voltage switchgear over the last fifty years, has a GWP of 24,300. Backed by substantial funding from the EU Programme for the environment and climate action (LIFE) and carried out in partnership with the Belgian electricity transmission system operator (TSO), the pilot Blue GIS will be installed at a TSO substation in Belgium; the joint project began on October 1, 2024 and is scheduled to continue until September 30, 2028. The flyer summarizes the project's six work packages, from project management and LPIT technology development through pilot realization and operation to impact monitoring and the replication and commercialization of the Blue 420 kV GIS technology. This is a project flyer: it contains no technical ratings table, and no equipment specifications are stated beyond the 420 kV voltage class and the F-gas-free clean-air/vacuum/LPIT technology set.
Almost all high-voltage electrical switchgear in the last fifty years has used SF6-gas for insulation. SF6 is extremely climate-hostile, with a global warming potential (GWP) of 24,300. Clean air insulation and vacuum switching technology, both of which have a GWP of zero, are increasingly used in 72.5 kV and 145 kV switchgear as an alternative to SF6. Until now, however, these have not been commercially available in 420 kV equipment. Both technologies stand for zero compromise in respect of the environment, health and safety.
The aim of the LIFE Blue project is to demonstrate for the first time the economic viability of a climate-friendly 420 kV gas-insulated switchgear (GIS) completely free of fluorinated greenhouse gases (F-gases) and intentionally free of PFAS with a digital low power instrument transformer (LPIT). Backed by EU funding and in partnership with the operator of the electricity transmission network in Belgium, this Blue GIS will be installed at a transmission system operator (TSO) site.
The GIS will be extensively tested and monitored on an ongoing basis. The flyer summarizes the project's work packages in six stages: project management and coordination; product and technology development; pilot realization; pilot operation; impact monitoring and evaluation; and sustainability, replication and exploitation of project results.
Collaboration is key in all of our projects. Here Siemens Energy is working closely with the EU Programme for the environment and climate action (LIFE), which has provided substantial funding, and with Belgium's electricity system operator — a valuable customer for many years.
This joint project began on October 1, 2024, and is scheduled to continue until September 30, 2028.
Efficient project management, including timely reporting to the European Commission (EC), auditing, risk management, and monitoring of progress and costs. Updating of the project management plan, organizing meetings, ensuring that deliverables and milestones are met, and appointing an independent auditor. Procurement activities and permission processes for the pilot installation.
Development and validation of the low power instrument transformer (LPIT) technology through extensive type and qualification tests. Equipment testing under high-voltage conditions, monitoring of transient response performance and electromagnetic compatibility, plus temperature and vibration tests. Preparation of LPITs for pilot application and interoperability testing with various Intelligent Electronic Devices (IEDs).
Detailed planning, manufacturing, and installation of the pilot site at the TSO substation. Site preparation, civil works, removal of existing switchgear, and integration of the new SF6-free Blue 420 kV GIS technology. Delivery, installation, and commissioning of the pilot bay, ensuring minimal outages during implementation.
Operation and monitoring of the Blue 420 kV GIS under real operational conditions. Evaluation of performance during seasonal variations, monitoring of system reliability, and collection of data on the durability of components and operational efficiency. Maintenance activities and specific test protocols to ensure a thorough evaluation of the pilot's performance.
Assessment of the technological, environmental, and socio-economic impacts of the project. Analysis of testing and operational data, plus life cycle assessment (LCA) to quantify environmental benefits. Evaluation of the project's contribution to job creation, market trends, and awareness of climate-neutral technologies.
Dissemination of project results, fostering links with other EU-funded projects, and ensuring replication and commercialization of the Blue 420 kV GIS technology. Creation of a business plan, development of a replication strategy for future installations, and continuing dissemination and exploitation efforts after the project concludes.
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