Balancing Tool Chain: Balancing and automatic control in North Sea Countries in 2020, 2030 and 2050

Abstract

This report analyses a study in the balancing operation of the power system of North Sea countries with focus on the Danish power system and its regions DK1 and DK2. The study covers all the steps of the operation from the Day Ahead Market to the Real Time balancing of generation and demand. For that reason, a balancing tool chain has been developed. The report analyses a) the value of offshore grid on balancing of forecast errors, b) the impact of forecast errors on manual and automatic reserves and c) the quality of electrical frequency in the near future considering high VRE penetration. The simulation results clearly shows that the offshore grid scenario has very similar impact on balancing of reserves to project based scenario. Since offshore grid scenario provides additional values like increased security and flexibility as well as larger integration of North Sea countries, having similar impact on balancing as that of project based, makes offshore grid an recommendable option for future grid development. Additionally, real-time imbalance in Nordic network is much lower in case of Offshore grid scenario as compared to Project based scenario. Day ahead market simulations for future shows higher amount of curtailment mainly pertaining to very high volume of installation of wind power. However, the volume of wind power curtailed is still low as compared to the total amount of wind power generation. This being the reason, there is no seasonal pattern in the curtailment of wind power in future scenarios. Simulations have shown that in future, hour ahead imbalance due to wind forecast error increases in Denmark mainly in DK1. However, the hour ahead imbalance for the whole synchronous area does not increase much. Therefore, intra-hour balancing of Danish control area is largely supported from neighboring regions. Balancing cost which is highly driven by $CO_2$ prices in the simulation, increases substantially towards 2030. Balancing reserves in CE are largely provided by Natural Gas technologies whereas, in Nordic network, balancing reserves come from Hydro and Natural Gas. Balancing reserves in Denmark mainly come from Natural Gas. However, wind power also increases their role in balancing process in future, mainly in down regulation but also in up regulation especially if wind power is already curtailed in the day-ahead operation. Real time imbalance seen by Nordic network increases multiple times in 2030 and 2050 scenario as compared to 2020 scenario. Additionally, the real time imbalance in Offshore grid scenario is much lower than that of Project based scenario. Nordic network is also expected to have much lower inertia available in future scenarios as compared to 2020 scenario. The requirement for automatic frequency restoration reserves increases manifold in future scenarios as compared to 2020 scenario. Probabilistic dimensioning of frequency restoration reserves can be beneficial to mitigate the imbalances caused by wind power forecast error mainly in Nordic network. Even with proper dimensioning of frequency restoration reserves, frequency containment reserve for normal operation in Nordic network might be required to be increased in future 2030 and 2050 scenario with very high share of renewables in the power system.