Det finns en ökande efterfrågan på förnybar elproduktion och effektiva lösningar att kombinera med denna. Ett flertal tidigare arbeten har undersökt energilagringssystem (ESS) och dess lönsamhet i olika tillämpningar. Det råder en osäkerhet kring lönsamheten hos ESS för ökad självkonsumtion i Sverige. Detta arbete undersöker lönsamheten hos batterilagringssystem (BESS) som används i syftet att öka självkonsumtionen för aktörer med solceller i den svenska bostadssektorn. En modell konstruerades baserat på Levelized Cost of Storage (LCOS), och indata till modellen varierades för olika scenarier. Resultaten visade att BESS kostnader i dagsläget är för höga, med LCOS mellan 1,68 kr/kWh och 3,56 kr/kWh beroende på aktör och indata. För lönsamhet krävs reduktion av LCOS mellan 55% och 85%. Vidare undersöker arbetet vilka variabler som har störst påverkan på BESS lönsamhet. En känslighetsanalys genomfördes, där CAPEX, antalet battericykler per år, WACC och skattereduktioner vid elhandel identifierades som viktiga variabler. Arbetet visade att det antagligen krävs en kombination av högre elpriser och reducerade investeringskostnader för att motivera en investering i BESS. Utöver ökad självkonsumtion behövs ytterligare värden för att motivera en investering i BESS inom en snar framtid. / There is a growing demand for renewable power generation and efficient solutions to combine with renewables. Previous works have explored energy storage systems (ESS) and their profitability in various applications. There is an uncertainty about the profitability of ESS for increased self-consumption in Sweden. This thesis explores the profitability of battery energy storage systems (BESS) used for increased self-consumption for stakeholders with solar photovoltaics in the Swedish residential sector. A model based on levelized cost of storage (LCOS) was constructed, and varying input values were used for different scenarios. The results showed that the current cost of BESS is too high, with LCOS ranging between 1,68 SEK/kWh and 3,56 SEK/kWh depending on the stakeholder as well as input data. For profitability, a reduction of LCOS between 55% and 85% is needed. Furthermore, this thesis explores which variables have the greatest effect on a BESS’s profitability. A sensitivity analysis was conducted, where CAPEX, the number of battery cycles per year, WACC and tax reductions linked to electricity trading were identified as important variables. This thesis concluded that higher electricity prices in combination with reduced investment costs is needed to justify an investment in BESS. Besides increased self-consumption, other values are needed to justify an investment in a BESS in the near future.

This study will examine a strategy for evaluating energy storage projects by integrating valuation metrics from finance and the energy sector. Uncertainty is one of the key barriers to investment in the energy sector (Shimbar & Ebrahimi, 2017, p. 349) and therefore financial modeling that allows comprehensive valuation of energy investment is necessary (Berrada, 2022, p. 407). The purpose of the study is to propose a strategy for evaluating energy storage projects that applies to investors and decision makers.  LCOS is a necessary component of energy storage project valuation, as it considers both the financial and technical performance of energy storage systems (ESS). Existing research in the field has contradictory opinions regarding the usefulness of LCOS and traditional financial valuation models for investment decisions in the energy storage sector. Few studies have combined modeling from the financial and energy sector. The authors have identified a need to introduce an investor perspective to business research in the energy storage sector. The authors conduct an explorative mixed-method study with an underlying non-positivist philosophical position. The case study design includes creation of five hypothetical energy storage projects to simulate an investment scenario. The authors utilize a point-base system to integrate valuation models from the energy and financial sectors, which include NPV, IRR, payback period, LCOS and technological maturity. Experts in the field provide input for which metrics are emphasized by practitioners. The projects are ranked based on stand-alone metrics, an integrated model and expert opinion. The results indicate that integrating numerous valuation metrics is necessary for analyzing and comparing energy storage investments. The financial viability of projects change based on individual metrics and integrated financial models. Furthermore, the results indicate that LCOS should be reinforced by financial indicators when making investment decisions. The expert input shows that investors emphasize valuation metrics differently, which indicates that the economic attractiveness of energy storage projects varies among investors. IRR is used by practitioners as a primary indicator for profitability. Future research should investigate a method for including sustainability indicators in the valuation process. Furthermore, as data accessibility is an issue in the field of study, future studies should collaborate with practitioners to generate more secondary data sources. Lastly, the impact of discount rates, risk premiums and investor preferences should be researched to better understand investment in the sector.

As intermittent renewable energy sources such as wind and solar power gradually increase around the world, older technologies such as nuclear power is phased out in Sweden and many other countries. It is then important to ensure that the total power need is secured, and that the power grid can remain stable. One way of managing intermittent renewables is by using energy storage. The main goal of this thesis was to compare energy storage methods and their costs. A secondary aim was to investigate how the cost of developing more renewable energy sources, in combination with different energy storage methods, compares to erecting new nuclear power. This thesis was limited to three energy storage technologies, namely pumped hydro storage (PHS), compressed air energy storage (CAES), and four battery storage technologies. They were combined with wind power in the cost analysis. The comparison was done by performing a literature review and economical calculations, which focused especially on levelized cost of storage (LCOS). The results from the economic calculations indicated that PHS and CAES had lower LCOS than battery storage technologies. Similar results could be seen in the literature review as well. When comparing levelized cost of energy (LCOE) nuclear power had the lowest, €0.03-0.12 kWh-1, followed by wind power in combination with PHS and CAES, both around €0.07-0.24 kWh-1. This result was maintained also at sensitivity analysis regarding the discount rate, which both nuclear power and PHS proved rather sensitive to. Keywords: energy storage, nuclear power, wind power, pumped hydro storage, compressed air energy storage, battery energy storage, levelized cost of energy, Sweden