Conditions and Requirements for the Technical Feasibility of a Power System with a High Share of Renewables in France Towards 2050

Conditions and requirements for the technical feasibility of a power system with a high share of renewables in France towards 2050 Abstract Acknowledgements, contributors and credits Table of contents List of figures List of boxes List of tables Executive summary Context High shares of renewables and the role of this report Key findings on technical feasibility 1. System strength, with a focus on reduction of inertia 2. Adequacy and flexibility resources to cope with the variability of wind and solar PV 3. Operational reserves 4. Grid development Next steps Chapter 1. Introduction Chapter 2. Renewable energy scenarios in France’s National Low-Carbon Strategy The low-carbon strategy relies on massive integration of decarbonised energy sources and reduction of energy consumption The French Low-Carbon Strategy assumes an increase in electricity consumption From energy projections to a detailed analysis including hour-by-hour assessment of security of supply Scenarios with high shares of renewables will rely mainly on wind and solar PV The National Low-Carbon Strategy is largely consistent with IEA low-carbon scenarios References Chapter 3. Resources for power system flexibility: International experiences and the French context Challenges of integrating large shares of renewables Flexibility resources Flexibility from generators Flexibility of France’s thermal fleet according to the French Multi-Annual Plan and National Low-Carbon Strategy Opportunities to increase generator flexibility Improved flexibility of thermal plants through retrofits Ensuring the deployment of flexible variable renewable generation Bioenergy-based generation could provide more flexibility running as peakers Flexibility sources beyond generators International experience and opportunities for demand flexibility Time-of-use pricing in California PJM’s demand response solution French potential for demand-side response Experiences and opportunities for flexibility from battery storage Hornsdale Power Reserve Potential for storage in France Using electrified transport to boost flexibility DC V2G in Denmark V2G in UK Opportunities for flexibility from electric vehicles in France Potential flexibility from power-to-gas French potential for sector coupling in the SNBC Interconnections, electricity consumption and mix at the European level References Chapter 4. Ensuring grid stability in systems with high shares of variable renewables The historical role of the inertia of synchronous rotating machines for electrical systems Variable renewables connected to the grid by power converters behave differently Technical challenges beyond inertia: system strength and stability Compensating for the decrease in inertia as the share of conventional generation decreases Maintaining a minimum of conventional generation operating instantaneously in the power system Developing new fast frequency response services The example of FFR from variable speed wind turbines in Québec Preparing Ireland’s power system for higher shares of converter-based infeed Limitations of FFR Installing synchronous condensers, a well-known and robust solution for ensuring the inertia of a power system Synchronous condensers in Denmark to cope with low thermal infeed Synchronous condensers as a solution for system strength issues in South Australia Limitations of synchronous condensers Grid-forming converters: using renewable generators or batteries to set system frequency Experience with grid-forming capabilities Grid-forming controls can contribute to stabilise synchronous generation Grid-forming services provided 100% by converters appear theoretically viable Challenges for the widespread use of grid-forming converters Beyond grid-forming converters, increased deployment of IT and digital controls requires greater digital resilience Protection against faults will need to be adapted Way forward References Chapter 5. Security of supply High shares of renewables will profoundly change the management of system adequacy Changes in generation profile pose challenges for security of supply and system balance Solar PV Wind Massive integration of variable renewables requires rethinking power system management Massive integration of variable renewables requires deeper sector coupling Security of supply can be technically ensured in a power system with a high share of variable renewables and different mixes of flexibility resources From technical feasibility to broader policy questions The significant volume of additional flexibility sources prompts the need to assess system costs in future analyses Significant steps are needed to take flexibility resources from demonstration to deployment Pace of deployment Industrial maturity In a power system relying mostly on renewables, the definition of security of supply itself could evolve Current practices in security of supply References Chapter 6. Short-term balancing and frequency regulation: reserve requirements and provision Operational reserves and real-time balancing are important features of the operation of a power system The supply-demand balance forecast encompasses many short term uncertainties that remain substantial today for some renewables Wind and solar PV production forecasts are based on weather forecasts and available real time data The estimation of conventional power plant output is based on scheduling and leads to almost no uncertainty close to real-time Forced outages Setpoint changes at round hours Combining weather forecasts and real-time monitoring to forecast load Grid does not encompass major uncertainty Uncertainties only decrease in the last hours before real time because of the effect of real-time estimations Ensuring the supply-demand balance requires anticipating reserve needs The different reserves and their interactions Sizing of automatic reserves Sizing manually activated reserves Challenges to short-term balancing at high shares of variable renewables Assessing reserve requirements with high variable renewables Expected changes in sizing of automatic reserves Managing a significant increase in upward reserve requirements A likely significant increase in downward reserve requirements Expected new dispatchable capacities to provide reserves New operational challenges The way forward for managing reserves at high shares of renewables References Chapter 7. Transmission grid Radically transforming the electricity mix requires major new grid routes in France and Europe In 2050, the network will remain a large-scale pooling tool to enable a more distributed, more variable mix Structural changes in the transmission grid structure by 2050 will be necessary and are under study Emergence of grid reinforcement needs by 2050 High ambitions for offshore production require an offshore grid Changes in the French and European electricity mix raise questions about interconnections Widespread ageing of regional networks will lead to massive restructuring needs Identical network renewal is not the only way to guarantee high electricity quality Network flexibility as an option for power system transformation Dynamic line rating Battery storage for network congestion relief Voltage management with high share of decentralised renewable generation Problems related to low voltage Problems related to high voltage References