HYBUILD focuses on the development of two innovative compact hybrid electrical/thermal storage systems for stand-alone and district connected buildings including solar. The project aims at developing cost-effective and environmental-friendly solutions, while ensuring comfort conditions in residential buildings located in two different climates: Mediterranean climate where cooling is critical; and Continental climate where a stronger focus is put on heating demand. The project is led by the Spanish group COMSA Corporación and it associates 21 partners from 11 EU countries including Fresnex GmbH. It started in October 2017 and is running for 4 years. The project was selected as part of the Energy-efficient Buildings Public-Private partnership.