대학건물의 전력소비패턴 분석을 통한 태양광, ESS 적정용량 산정 및 경제적 효과 분석

Calculation of Photovoltaic, ESS Optimal Capacity and Its Economic Effect Analysis by Considering University Building Power Consumption

Abstract

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.

Fig. 1 Electric charges discount by ESS

Fig. 2 Power usage of 1^st semester (2018.05.09.)

Fig. 4 Power usage of 2nd semester (2017.10.25.)

Fig. 3 Power usage of summer vacation (2018.07.09.)

Fig. 5 Power usage of winter vacation 2018.01.08.)

Fig. 6 PV Utilization rate by time[6]

Fig. 7 Algorithm of Photovoltaic

Fig. 8 Graph of 1^st semester’s power using 20kW,30kW, 40kW PV

Fig. 9 Graph of 1^st semester’s power using 10kWh ESSESS

Table 1. Electric charges seasonal⋅time division

Table 2. Educational electric charges system 교육용 전력(갑)

Table 3. Example of electric charges system

Table 4. 1^st semester’s power using 10kW PV

Table 5. Expected electric charges

Table 6. Payback period by PV

Table 7. 1^st semester’s power using 10kWh ESS

Table 8. Payback period by ESS