CROSSBOW will propose the shared use of resources to foster cross-border management of variable renewable energies and storage units, enabling a higher penetration of clean energies whilst reducing network operational costs and improving economic benefits of RES and storage units . The objective is to demonstrate a number of different, though complementary, technologies, offering Transmission System Operators higher flexibility and robustness through: 1) A better control of exchange power at interconnection points; 2) new storage solutions – distributed and centralized-, offering ancillary services to operate Virtual Storage Plants (VSP); 3) better ICT and Communications -e.g. better network observability, enabling flexible generation and Demand Response schemas; 4) the definition of a transnational wholesale market, proposing fair and sustainable remuneration for clean energies though the definition of new business models supporting the participation of new players –i.e. aggregators - and the reduction of costs. The CROSSBOW results will be evaluated by 8 TSOs in Easter Europe, grouped to form clusters that will validate each of the projects outcomes in at least three different countries, demonstrating in all cases how CROSSBOW tackles the transnational challenges faced by these TSOs.