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As interest in deploying Battery Storage systems (BSSs) grows, a significant challenge is to determine the specific services that the BSS should provide to maximize profits. This study aims to determine the most profitable strategy and size of integrated grid-connected BSS with and without PV park for participating in Day-Ahead Market (DAM) and Frequency Regulation Market (FRM). The Frequency control services activate in response to changes in the electricity grid frequency, with BSS supporting during frequency fluctuations. The focus of this study is on the primary regulation within FRM. In this study, a BSS operation algorithm is evaluated in economic terms. The algorithm imports inputs like market prices, fees, tariffs, PV production, and chosen BSS service. Economic metrics include Net Present Value (NPV) and Internal Rate of Return (IRR). Real-world data from a Swedish PV park was used for case studies across three categories: BSS stand-alone, PV park alone, and PV-BSS combination. Results highlight that stand-alone BSS scenarios are superior to PV-BSS combination cases, showing a 73% Internal Rate of Return (IRR) for a 1000 kWh/400 kW BSS configuration. PV park alone participation in FRM and DAM shows marginal benefits compared to only acting on the spot market. The sensitivity analysis examining changes in prices for both DAM and FRM relative to 2022 reveals a significant negative change in revenue in 2020, which is explained by the higher and more fluctuating electricity prices. Lastly, the sensitivity analysis explores changes in the acceptance rate of bids in the future relative to 2022, as FCR products will be procured at a marginal price. These analyses indicate potential negative changes that may occur as the acceptance rate may decrease.

A significant challenge is to determine the specific services Battery Energy Storage System (BESS) should provide to maximize profits. This study investigates the most profitable markets and sizes of BESS with utility-scale solar Photovoltaics (PV) power plants using techno-economic analysis frameworks. The objective is to maximize profitability in energy and frequency markets, focusing on primary regulation and day-ahead markets for Sweden and Germany. The inputs are historical market prices and frequency data, as well as real measurement PV power data. The results show that adding a BESS to an existing PV park does not result in a lower payback period than if implementing a stand-alone BESS. However, the payback period differs between Sweden and Germany during 2023, i.e., being 1.8 and 6.8 years, respectively. This is explained by the lower frequency market prices for Germany compared to Sweden. The technical results indicate that the BESS energy capacity after 10 years of operation is approximately 83% for Germany, whereas, for Sweden, it is around 87%. Also, combining the operating of BESS on primary regulation and day-ahead markets showed a 6-year payback period with a slight increase in loss of energy capacity (from 83 to 80%) for Germany. Moreover, combining various PV-BESS sizes showed a discrepancy in economic and technical metrics for the BESS in Germany, resulting in a best-case of a 6-year payback period. A sensitivity analysis, which examines a drop in the frequency control prices in the future relative to 2023 (by 20% and 50% for Germany and Sweden, respectively), reveals an increase in the payback period for both countries by approximately 1 year.

In Sweden, Svenska Kyrkan (the Church of Sweden) has over 3300 churches. A majority of the churches are electrically heated. Usage patterns of electrically heated buildings such as church buildings, creating problems for the grid and the church organization through increased grid fees. Simultaneously, interest in deploying Battery Energy Storage Systems (BESSs) is growing. A significant challenge is determining the specific services the BESS should provide to maximize profits for the owner. For church load profiles, with the help of a battery, the church consumption peaks can be shaved. Additionally, when the Battery Energy Storage System (BESS) is not used for this purpose, it can instead be employed to support the grid through participation in the frequency regulation market. Frequency control services are activated in response to changes in the electricity grid frequency, with the BESS providing support during frequency fluctuations. The objective of this study is to investigate the economic value of installing BESS in a church powered by a PV system. Various frequency regulation services, with a focus on primary reserve, are explored. The model operates on other energy markets, which are local flexibility and day-ahead markets. The inputs include selected services, feed-in and feed-out profiles, historical frequency data, and frequency regulation and energy market prices over the year 2023. The case study involves measured data from Kila Church, which has a 60 kWp solar power system and is located in mid-western Sweden. The economic metrics are net present value and payback period, whereas technical and environment metrics are the battery degradation and CO2 emission equivalents, respectively. This study indicates that the investment in BESS is profitable if the BESS operates on frequency stability services together stacked with Peak Shaving (PS). The results show a 1.6-year payback period for a 120 kWh/60 kW BESS. A sensitivity analysis explores future changes in prices of the frequency regulation market and BESS shows that FCR-D Up has more sensitivity for a drop in the prices in the future. Nevertheless, FCR-D Down has more economic potential value. Conclusively, BESS would be a beneficial investment for churches and facilities with similar load and PV power generation profiles, both from an economic and societal perspective.