Techno-economic assessment of a co-located PV–wind–BESS system underwholesale market prices with linear programming-based EMS optimization

This paper evaluates the techno-economic performance of a co-located photovoltaic power plant and wind power
plant, each with an installed capacity of 36.8 MW, under wholesale market conditions in North Macedonia. Three operating scenarios are considered: a reference case without battery energy storage, a storage case with rule-based dispatch implemented in Excel, and a storage case with an optimized energy management system developed in MATLAB. In the storage configurations, each plant is coupled with a dedicated battery energy storage system sized at 20% of the installed power, with a discharge duration of two hours. The analysis is conducted in two stages. First, an hourly operational and revenue assessment is performed for the base year 2025 using hourly electricity prices from the Macedonian Electricity Market Operator (MEMO). Hourly photovoltaic generation is obtained through plant design and simulation in PV*SOL premium, while hourly wind generation
is based on measured production data from the Bogdanci wind farm. Second, a 25-year financial assessment is carried out, including annual revenues, operating costs, loan servicing, depreciation, and net cash flow, net present value (NPV). The results show that battery integration increases market revenues relative to the case without storage, while the optimized EMS provides further improvement compared with the rule-based dispatch strategy. Among the three main scenarios, the optimized EMS case achieves the highest annual revenue, the highest NPV, and the shortest payback period. In addition, a sensitivity analysis is performed for the optimized EMS case by varying battery power and energy capacity. The results indicate that project profitability can be further improved through appropriate BESS sizing, with the highest NPV obtained for a total project BESS
configuration of 29.44 MW / 88.32 MWh. The study confirms that the economic value of battery storage in co-located PV-wind systems depends strongly on both the dispatch strategy and the selected battery size.