This project aims to realise G-TECH as a Flemish living lab in the field of thermal energy. G-TECH will be a state-of-the-art, open innovation ecosystem, where state-of-the-art test infrastructure will be made available to the Flemish industry, with a view to scaling up and commercializing sustainable energy technologies to XL format. Within Europe, Belgium and Flanders, the transition to a fossil-free society is an important policy priority, in which innovation is central. The spearhead clusters Flux50 and De Blauwe Cluster, as facilitators of cooperation on innovation in the triple helix context, play a key role in Flemish innovation policy. An important element in the strategy of Flux50 is the realization and support of living labs. These testbeds are innovation ecosystems where energy technologies are tested and improved in real interaction with end users and other components. After this phase, the innovations are ready for a go-to-market. An analysis by Flux50 of the existing living labs in Flanders showed important gaps in the domain of sustainable heat and fuels, despite the great need for further innovation in this domain (identified by dozens of industrial members). This was the reason for the G-TECH project, which will work on three substantive pillars, in response to the challenges formulated by the Flemish companies: Pillar 1: Sustainable heat production and storage in industry; Pillar 2: Sustainable heat production and storage in the residential sector; Pillar 3: Sustainable fuels for the energy and transport sectors. G-TECH focuses on industrial end-users for sustainable energy use (energy-intensive industry; residential developers; heavy transport) and associated value chain (finished products such as heat pumps; components such as compressors; and support services). In collaboration with research institutes, these companies will be able to test new components and new entire systems of heat exchangers, compressors, heat pumps and motors in power ranges from 10 kW to 500 kW, which is unique in Europe. Concretely, a test hall will be built within G-TECH with a net floor area of 2,953 m2 consisting of test setups, a workshop and a training and demo room. The test hall includes air-conditioned rooms for testing heat pumps, test stands for heat transfer and energy storage in Phase Change Materials, a test set-up for determining the state of charge of thermal batteries, test stands for studying two-phase behaviour in compressors and accumulators of heat pumps and test benches for testing organic rankin cycles. With its strong focus on valorisation, G-TECH aims to achieve an economic impact in Flanders by contributing to the commercialisation of thermal energy solutions by the companies. The economic impact is measured by increased energy efficiency, increased investments by companies in sustainable technologies, the introduction of new technologies to the market and the creation of new jobs and will therefore also achieve a positive climate impact.