Rasmus Bo Bramstoft Pedersen: Modelling the Future Nordic Energy System with a High Penetration of Renewable Energy Sources, MSc Thesis, DTU, 2016
The Nordic countries has set ambitious long-term energy policy targets which aims to reduce the environmental greenhouse gas (GHG) footprint from the energy system. Therefore, the future Nordic energy system is expected to include a high penetration of both variable- and dispatchable renewable energy sources. The variable renewable energy sources (VRE) i.e. wind and solar, are characterised by a highly variable energy production, uncertain production due to forecasting errors, and location specific production since the primary energy resource used cannot be transported. These characteristics can cause increased system costs and challenges. To facilitate an efficient integration of the increased penetration of VRE in the future, four flexibility resources i.e. flexible generation, demand-side flexibility, energy storage facilities and transmission grid infrastructure, can be further introduced into the system. The main objective in the present thesis is to quantify options for integrating fluctuating renewable energy sources for electricity in the future Nordic energy system towards 2050 with emphasis on two of the flexibility resources, namely, transmission grid infrastructure expansions, and demand-side flexibility. This objective will be met by performing a theoretical literature study and further by implementing an energy system optimisation model. The quantitative assessment is conducted by use of the energy system optimisation model - Balmorel - which is an effective tool for long-term investment planning of the power and district heating. The Balmorel model is improved by expanding the geographic representation and updating the data base in order to simulate the future Nordic energy. The quantitative assessment include two case studies, 1) Assessment of future expansion og the transmission capacity, and 2) Assessment of demand-side flexibility. The results in the first case study shows that the transmission capacity is expanded in all investigated scenarios which illustrate the socio economic benefit of additional transmission capacity. In the Base scenario, a high utilisation of wood pellets CCS technologies is found, which is identified to be caused by the implemented CO2 price. Furthermore, the annual average electricity prices, the electricity exchange and endogenous investment in additional generation capacity is investigated for the Base scenario, an Alternative scenario and four sensitivity scenarios. In the second case study demand-side flexibility (DSF) is introduced into the system. The results from the Balmorel simulation show a reduced amount of additional transmission capacity compared to the Base scenario. Furthermore, in general, the electricity prices will be reduced when introducing DSF. In addition to the long-term investment scenario, an hourly simulation for the demand-side flexibility scenario is conducted and illustrated for four representative weeks to clarify the functionality of the implemented demand-side flexibility.