| Fuel shortages and environmental problems are exacerbated by China’s growing energy consumption.The use of clean and renewable energy is of great importance to energy conservation and emission reduction and the achievement of dual carbon goals.Building energy consumption in the total energy of the national social accounted for more than thirty-seven percent,its energy-saving potential is very big,and construction with the combination of photovoltaic(PV)is an ideal form of solar energy using photovoltaic(PV).The power generation can provide electricity to the building and is not limited by geographical condition,the power to the electric grid also can effectively alleviate the pressure of the power grid peak power,and bring economic value.In this paper,DesignBuilder was used to establish the teaching building model and calculate the load based on the building characteristics of Changsha University of Science and Technology,a simulation model of the "photovoltaic&energy storage" integrated system was built with TRNSYS.Based on the verified research method,analyze the impact of attendance(number of students),annual classroom utilization rate,teaching time,and air-conditioning utilization rate in summer vacation on economy and electricity characteristics between generation,network,and demand side.The results show that:1)From the overall demand,the solar energy generated by the integrated teaching building system of centralized air-conditioning and optical storage can basically meet the demand for air-conditioning electricity,and there is more electricity for the power grid.2)In summer,the electricity consumption of air conditioning decreases with the decrease of attendance,when attendance decreases by 0.25,the electricity consumption of air conditioning decreases by about 10%,and the power to the electric grid increases by about 9%in June.The annual classroom utilization rate decreased from 1 to 0.8 and from 0.8 to 0.6 in June,the electricity consumption of air conditioning decreased by 13%and 16%respectively,and the power to the electric grid increased by 12.6%and 12.8%respectively.The increase in self-study at night resulted in a 23%increase in air conditioning power consumption and a 19%decrease in the power to the electric grid in June.Air conditioners with a utilization rate of 0.2 in the summer use 15%of the electricity generated in the whole summer.3)The power consumption of air conditioning in winter increases with the decrease in attendance.When the attendance is decreased from 1 to 0.75 and from 0.75 to 0.5,the power consumption of air conditioning increases by 34.6%and 47.5%respectively,and the power to the electric grid decreases by 3.7%and 7.3%.The annual classroom utilization rate decreased by 0.2,the power consumption of air conditioners decreased by about 7%,and the power to the electric grid increased by about 0.7%.In winter,the increase in self-study at night led to the electricity consumption of air conditioning decreased by 1.8%,and the power to the electric grid increased by 0.18%.4)The solar fraction range of the system is between 0.85-1,the self-consumption ratio is between 0.09-0.22,and the ROI(Return on investment)is between 0.100-0.213.The ROI of the system is small and the risk is low.The payback period ranges from 4.7 to 10 years,and the annual classroom air conditioning utilization rate has a significant impact on the payback period. |
