Identifying solutions to address the need
Addressing tomorrow’s challenges will require the parallel development of all possible solutions, including not only different transmission technologies or connections and routes, but also electricity storage, the role of prosumers and generation, in addition to reinforcing the transmission grid.
Once a need has been identified, it is necessary to identify the possible options to address the need, considering these options’ respective costs and overall benefits for the power system.
In future, infrastructure planning will require to go even further, with a truly multi-sectorial approach, considering electricity assets but also gas, transport and heat. Smart sector integration will enhance flexibility across various energy sectors and allow a development towards a more energy- and cost-efficient energy system. ENTSO-E’s roadmap for the development of multi-sectorial planning towards 2030 (MSPS) is meant to serve as a starting point.
Assessing alternative solutions
The French TSO RTE investigated in its 2019 national development plan the cost-effectiveness of various solutions to tackle occasional and structural constraints, including power-to-gas, battery storage, limitation of wind generation via active network management controllers, compared to reinforcements of the transmission network. While limitation of production proved to be the most cost-efficient solution in case of occasional grid constraints, for structural constraints economic analyses show that reinforcing the network remains, for the moment, the most economical solution in general case (see figure). In the mid- to long-term, battery storage and power-to-gas could be additional solutions provided that specific conditions are met in terms of where they are located (near renewable energy production sites) and how they are used. The possible decrease of the cost of the batteries and the evolution of their benefits from other services could also increase their competitiveness and interest for congestion management.
In 2021, RTE will carry out experimental calls for tenders that put in competition market assets offering flexibility services – such as battery storage – with network reinforcement projects. This experimentation will focus on regional network congestions and on some cases where batteries are most likely to be competitive as early as today: thus, batteries mainly used for frequency containment reserves could get additional revenues by providing a congestion management service, and associated grid reinforcements could be postponed or even avoided.