• Energy Research

Due to ambitious national and EU level climate targets, wind power capacity in Finland has grown rapidly, while a significant amount of thermal capacity has been decommissioned or mothballed. Moreover, Finland is growing more dependent on electricity imports and the current electricity prices do not encourage market-based investments in power capacity. Hence, the issue of power capacity adequacy during winter peaks has been present in the political discourse in Finland, especially since the record-high demand peak in January 7th 2016. We analyse the Finnish power system by simulating different stress factors and their combinations, e.g. faults in the largest power plants and transmission lines, in a period such as January 7th 2016 using EnergyPLAN simulation tool. The results show that, despite the record-high demand, the Finnish power system currently has both technical capacity and adequate measures of intervention to cope with severe stress factors in the simulated period.

Efforts to provide alternative resources and technologies for producing liquid fuel have recently been intensified. Different levels of dependence on oil imports and carbon prices have a significant impact on the composition of the cost-minimizing portfolio of technologies. Considering such factors, how should China plan its future liquid fuel industry? The model for supporting the technology portfolio and capacity configuration that minimizes the total system cost until 2045 is described in this study. The results obtained for different carbon prices and levels of dependence on oil import indicate that the oil-to-liquid fuel (OTL) will remain dominant in China's liquid fuel industry over the next three decades. If the carbon price is low, the coal-to-liquid fuel (CTL) process is competitive. For a high carbon price, the biomass-to-liquid fuel (BTL) technology expands more rapidly. The results also reveal that developing the BTL and CTL can effectively reduce the oil-import dependency; moreover, a high carbon price can lead to the CTL being replaced with the low-carbon technology (e.g., BTL). Improvement in energy raw material conversion and application of CO2 removal technologies are also effective methods to control carbon emissions for achieving the carbon emission goals and ultimately emission reduction targets.

Energy system models are crucial to plan energy transition pathways and understand their impacts. A vast range of energy system modelling tools is available, providing modelling practitioners, planners, and decision-makers with multiple alternatives to represent the energy system according to different technical and methodological considerations. To better understand this landscape, here we identify current trends in the field of energy system modelling. First, we survey previous review studies, identifying their distinct focus areas and review methodologies. Second, we gather information about 54 energy system modelling tools directly from model developers and users. Unlike previous questionnaire-based studies solely focusing on technical descriptions, we include application aspects of the modelling tools, such as perceived policy-relevance, user accessibility, and model linkages. We find that, to assess the possible applications and to build a common understanding of the capabilities of these modelling tools, it is necessary to engage in dialogue with developers and users. We identify three main trends of increasing modelling of cross-sectoral synergies, growing focus on open access, and improved temporal detail to deal with planning future scenarios with high levels of variable renewable energy sources. However, key challenges remain in terms of representing high resolution energy demand in all sectors, understanding how tools are coupled together, openness and accessibility, and the level of engagement between tool developers and policy/decision-makers. Applied Energy, 290 ISSN:0306-2619 ISSN:1872-9118

Due to their properties, the most suitable application for flow batteries currently is a bulk energy storage. This paper investigates the economic feasibility of the technology in terms of monetary profitability in the appropriate business cases, namely employment in energy markets and in isolated island systems with the high share of renewable generation. We calculate the flow batteries life cycle costs and compare them with the potential revenues from participation in the Finnish energy markets and operation in isolated power systems of the Faroe Islands and the island of Graciosa. We find that the flow batteries exploitation in the Finnish market is not profitable - they collect 43-60% of their costs in the most promising application. The island cases represent a more viable option due to the high fuel costs of the thermal plants that the batteries and renewable sources substitute or decrease their share. However, the revenue and subsequent profitability highly depend on the volatile fuel prices.

Large-scale deployment of intermittent renewable energy (namely wind energy and solar PV) may entail new challenges in power systems and more volatility in power prices in liberalized electricity markets. Energy storage can diminish this imbalance, relieving the grid congestion, and promoting distributed generation. The economic implications of grid-scale electrical energy storage technologies are however obscure for the experts, power grid operators, regulators, and power producers. A meticulous technoeconomic or cost-benefit analysis of electricity storage systems requires consistent, updated cost data and a holistic cost analysis framework. To this end, this study critically examines the existing literature in the analysis of life cycle costs of utility-scale electricity storage systems, providing an updated database for the cost elements (capital costs, operational and maintenance costs, and replacement costs). Moreover, life cycle costs and levelized cost of electricity delivered by electrical energy storage is analyzed, employing Monte Carlo method to consider uncertainties. The examined energy storage technologies include pumped hydropower storage, compressed air energy storage (CAES), flywheel, electrochemical batteries (e.g. lead-acid, NaS, Li-ion, and Ni-Cd), flow batteries (e.g. vanadium-redox), superconducting magnetic energy storage, supercapacitors, and hydrogen energy storage (power to gas technologies). The results illustrate the economy of different storage systems for three main applications: bulk energy storage, T&D support services, and frequency regulation.

Abstract International climate policy debate has been struggling to define an agreeable principle for just distribution of the burdens of reducing greenhouse gases. By the integrated assessment modeling, we investigate climate change mitigation pathways compatible with the Paris Agreement goals under different carbon budget allocation principles, namely, cost-effectiveness, equality, and grandfathering for 11 world regions. The results indicate that regional carbon quotas remain similar under equality and grandfathering principles, except for regions with a high population projection, i.e., Sub-Saharan Africa and South Asia, or regions with a high level of current emissions, such as North America. Irrespective of the burden-sharing principles, most world regions must reach carbon neutrality before 2070 to meet the 2 °C climate targets. Moreover, carbon emissions reduced by carbon capture and storage applications are found to peak around 2050. In general, the share of fossil fuels in primary energy is larger under the larger carbon quota, which will also increase carbon capture and storage applications in fossil fuels. The average global investment needs for mitigating climate change are the lowest under the cost-effectiveness principle, and the marginal abatement cost is the same for all regions. For each region, as the carbon quota decreases the marginal abatement cost increases, while the energy investment changes independently from the carbon quota. These insights can inform global climate change negotiations and help policymakers formulate timelines for carbon neutrality, energy transition, and technology deployment and investment portfolios.