Bergvärme i kombination med solceller hos Skolfastigheter

Abstract: The purpose of this essay is to examine the dimensioning of sustainable energy systems for two properties in Uppsala, Länna school and Funbo preschool. This essay’s main focus is on the implementation of solar cells in combination with geothermal heat on the two mentioned buildings. In addition to the combination, storage options will also be investigated. The goal is to optimize the energy systems for the schools from both an energy and financial perspective and this will be viewed from the company Skolfastigheter AB’s perspective. Data from the schools containing energy use and energy demand along with hourly solar radiation are used in the method to create four different models that will be implemented on the properties. All models were created in the program MatLab, while the financial calculation was designed in Microsoft Office Excel. The result presents the monthly heat production from the geothermal heat pump for Länna school together with the electrical power demand for the year 2022. The essay only takes the implementation of solar cells and energy storage into account for Funbo, since they already have an existing geothermal heat pump. Länna school’s solar cell system had a total installed power of 19,0 kW, while Funbo preschool had 88,4 kW. The excess production from the solar cell system for Länna school and Funbo preschool was 5 550 kWh and 31 300 kWh respectively for the year 2022. The payback period for the main system for Länna school was 5,22 years and for Funbo preschool 9,63 years. The result is presented in graphs together with a financial estimate for each model and system where installation costs and operating costs were calculated. The conclusions are that geothermal energy in combination with solar cells is considered to be more energy efficient and environmentally advantageous compared to the current energy system for both schools. The main system together with hydrogen storage and battery storage is considered to be the most energy efficient dimensioning for the schools. From a financial perspective, the main system is considered the most profitable for Funbo preschool. For L¨anna school, the main system together with battery storage is considered as the best option, even though only the main system is most economically viable.