# Dynamic Energy Management Strategy of a Solar-and-Energy Storage-Integrated Smart Charging Station
###### Abstract  
Under net-zero objectives, the development of electric vehicle (EV) charging infrastructure on a densely populated island can be achieved by repurposing existing facilities, such as rooftops of wholesale stores and parking areas, into charging stations to accelerate transport electrification. For facility owners, this transformation could enable the showcasing of carbon reduction efforts through the self-use of renewable energy while simultaneously gaining charging revenue. In this paper, we propose a dynamic energy management system (EMS) for a solar-and-energy storage-integrated charging station, taking into consideration EV charging demand, solar power generation, status of energy storage system (ESS), contract capacity, and the electricity price of EV charging in real-time to optimize economic efficiency, based on a real-world situation in Taiwan. This study confirms the benefits of ESS in contracted capacity management, peak shaving, valley filling, and price arbitrage. The result shows that the incorporation of dynamic EMS with solar-and-energy storage-integrated charging stations effectively reduces electricity costs and the required electricity contract capacity. Moreover, it leads to an augmentation in the overall operational profitability of the charging station. This increase contains not only the revenue generated from electricity sales at the charging station but also the additional income from surplus solar energy sales. From a comprehensive cost-benefit perspective, introducing this solar-and-energy storage-integrated EMS can increase facility owners' net income by 1.25 times compared to merely installing charging infrastructure.  
energy management strategy; solar power; energy storage system; charging station; time-of-use (TOU); price arbitrage +
Footnote †: journal: Applied
systems, particularly focusing on the introduction of distributed generation architecture utilizing renewable energy, energy storage systems, and loads. It compares the feasibility, control, and energy management strategies of the two microgrid systems. [9] presents a DC microgrid architecture incorporating various generation sources and charging stations, accompanied by a real-time power management strategy that considers uncertainties such as the arrival time of EVs and their initial charging status. [10] proposes a community-based EV charging station energy management strategy that dynamically coordinates solar energy, the grid, and energy storage systems to meet EV demands. It dynamically allocates charging levels based on the state and departure time of each vehicle. [11] introduces a real-time charging management strategy based on a DC microgrid, utilizing Mixed Integer Linear Programming (MILP) for optimization scheduling.  
In Taiwan, a densely populated island with limited land resources, utilizing existing facilities such as rooftops of wholesale stores and parking lots to establish solar and charging infrastructure holds significant practicality and value. This approach not only accelerates the electrification of vehicles but also brings about economic benefits and contributes to carbon reduction.  
This paper proposes a dynamic EMS based on the actual situation in Taiwan, designed specifically for charging stations integrating solar energy and ESSs. The system takes into account EV charging demand, solar power generation, the state of the ESS, contracted capacity, and the dedicated electricity price for EVs to optimize economic benefits. The main contributions of this paper are as follows:  
1. Introducing a novel dynamic EMS for charging stations integrating solar energy and ESSs, with simulation and analysis based on the actual situation in Taiwan.
2. Confirming the multiple benefits of ESSs in contracted capacity management, peak shaving, and energy arbitrage.
3. Demonstrating that implementing the energy management strategy proposed in this paper can increase the overall net income, achieving 1.25 times the income compared to merely setting up a charging station.