The sustainability of our energy supply is in full swing. With the increasing share of sustainable energy, it is becoming increasingly important to integrate the associated innovations with each other, in order to keep the energy system reliable and affordable. Innovative SMEs in particular can accelerate this sustainability with the right products and services. However, it needs an environment in which these innovations can be easily and quickly tested. Integration issues related to integration into existing infrastructure and scaling-up issues are crucial in this context, in order to be able to contribute more quickly to the set CO2 reduction targets. Precisely for these aspects, the Hybrid Energy System Integration Facility (HESI) is being developed. The first market exploration carried out shows that there is currently a need for such a facility. Hesi is available to anyone who wants to use the services provided by HESI. Specifically, it targets companies and knowledge institutions from the energy sector, or related to them. These include ICT developers of energy services, energy and energy service providers, creators of equipment(products) for both energy and energy management (energy management) but also existing grid operators. It is precisely also the combination with energy infrastructure parties such as the regional grid operators which allows smaller parties to integrate their proposition into the energy system and to validate the operation on a large scale. Hesi offers services to this end, built around a reflection of the existing energy supply and combines them with state-of-the-art integration and control technology in an open research concept. This concept provides theunique of integration, scaling up and acceleration for innovations in the energy transition. Earlier, many small-scale test yards have been involved in testing technology, but the step towards large-scale deployment is lagging behind. Being able to test in an integrated environment is time-consuming if that environment still needs to be built up. Hesi offers this environment, so that the build-up time of test setups can be shortened and especially attention can be given to the quality and adaptability of products and services. For innovative SMEs, it is important that their self-developed energy technology integrates well with existing energy installations and performs optimally and creates value for the user/owner. In this context, the technology developer is confronted with finding a balance in the quality of the technology, the complexity in which the technology has to function and the lead time for market introduction. Hesi is unique in the Netherlands by combining integration, scaling-up and acceleration issues in the energy transition. Where the other laboratories at home and abroad focus on specific technologies, HESI then focuses on how innovations can be used in the existing system and how scaling up is possible. The plug&play way in which HESI approaches this approach accelerates the market uptake of these innovations.