Effective integration of renewable energy in Northern European energy systems

The European Union (EU) has committed to reaching carbon neutrality by 2050 at the latest, with Finland ambitiously pledging to reach net-zero carbon emissions already by 2035. Reaching these targets will require a rapid expansion in renewable energy generation over the next decade, which will mostly be facilitated by market incentives and private investments in the EU. Yet, it is still somewhat unclear what technologies will effectively enable different sectors to be decarbonized in the future, especially as increased energy market uncertainty and high electricity prices have become common in the last years following the war in Ukraine and the EU energy crisis in 2022. This thesis thus aims to provide new insights into how renewable energy use can be increased effectively in both individual and national energy systems in Northern Europe, with Publications I–III assessing the techno-economic feasibility of solar PV and energy storage systems in end-consumer applications in Finland, and Publications IV–VI focusing on how potential risks, limitations, and challenges may impact the transition to clean energy in Northern Europe.  The results of this thesis indicate that both smaller and larger locally installed solar PV systems can effectively increase the share of renewable energy in residential buildings and data centers in northern countries. Yet, in most cases, this necessitates selling surplus electricity to the grid to be cost-effective, as the use of energy storage to balance solar PV systems is shown to generally increase energy-related costs for end-consumers at higher latitudes. Moreover, the results highlight how resource adequacy and power supply security will be crucial in ensuring the effective transition to clean energy in Northern Europe. Notably, potential limitations in critical mineral and biomass availability pose significant risks to reaching national climate and energy policy targets in Finland and Northern Europe, as the global supply of many critical minerals is currently highly concentrated in a few non-EU countries and will have to be expanded considerably to facilitate the global transition to clean energy, and as Finland and similar countries will need to increase forestry carbon removals substantially to meet EU emission reduction targets for 2030 and to stay on track to attain national carbon neutrality targets. Additionally, the presented analysis suggests that new investments into flexible thermal power generation are necessary to cost-effectively balance the growing share of intermittent wind and solar PV generation in the Finnish power system by 2035. Subsequently, this thesis highlights how further action is needed to facilitate renewable energy integration and attain national climate targets in Northern Europe, as well as to guarantee resource adequacy and energy system reliability in the clean energy transition.