Contribution of storage technologies to renewable energy hubs

A holistic approach, considering all the energy needs of a territory, should be adopted in the challenge of the energy transition. Synergies between the different end-use demand sectors must be developed, in order to optimize the efficient use of resources. The multi-energy system of the future will be integrated and coordinated, with renewable energy sources and decentralized capacities. Indeed, in a context of increasing urbanization worldwide, decentralized renewable capacities appear to be the key driver to decarbonize urban environments and foster the emergence of renewable energy hubs. Mutualized infrastructures need to be deployed at every stage of these hubs: from energy harvesting, transport, and storage; to mobility services and goods production. The most suited scope to study the deployment and promotion of these local capacities and shared infrastructures appears to be the district perspective. The financial and environmental benefits of a district integrated approach for the mutualization of capacities have been proved, but their implementation mechanisms remain understudied. The aim of this study is to characterize the contribution of storage technologies to ensure the energy balance of a territory, assess the associated investments to be made, and discuss the techno-economic and environmental performance of the whole system. Firstly, a district is defined as a renewable energy hub, by identifying the energy needs of the residents and the potential of endogenous resources. Then, a Mixed Integer Linear Programming (MILP) model is developed to offer a multi-objective optimization of energy resources at district-level. Finally, a characterization of the storage technologies available under the horizon 2050 is conducted and a set of technological solutions is created to serve as input to the optimization model. Although their robustness has not been assessed, the obtained results show several interesting im- pacts. First, storage implantation allows to foster Photovoltaic (PV) deployment until full penetration. Sides effects to this increased penetration are a growth of the exported electricity together with a reduction of the imports. While the the latter is beneficial, the export increase might put the electric grid at risk. Second, synergies between electric and heat storage technologies where demonstrated through an increased use of heat technologies. Lastly, long term storage was not demonstrated and additional work should be undertaken to validate the overall model. Finally, once the developed model is corrected with the proposed improvements, it aims to be integrated in a global comprehensive model whose final purpose is to assess the optimal level of mutualization of energy conversion and storage capacities in urban areas.