Jämförelsestudie av kylmodeller förserverhallar i Sverige

Sammanfattning: Data centers around the world are using energy to process large amounts of data. Energy consumption is increasing with accelerating data usage, and data traffic is expected to increase by 20 percentage units each year between 2016 and 2022. More data center operators choose to place their data centers operation in Sweden due to favorable climate conditions, cheap renewable electricity and technical skills. In data centers, the IT-equipment generates a large amount of heat which must be removed to ensure that servers maintain their performance and service life. The abducted heat can either be ventilated to the surroundings or be used to heat other premises. In this study, four cooling models were developed and evaluated from an economic and environmental perspective. For the economic perspective, a life- cycle cost for each system was calculated for 20 years, and for the environmental perspective, the carbon dioxide emission generated by the cooling systems were analyzed. The cooling systems that were compared were district cooling, free cooling with a cooling tower, cooling machine and heat pump with heat recovery to a district heating network. The cooling systems were further assumed to be used in their respective optimal operating environment. The cost analyses showed that there were large differences in the total cost between each respective cooling system. Free cooling with a cooling tower had the lowest cost while district cooling accounted for the highest cost. Selling waste heat to a district heating supplier could in this study reduce the total cost by approximately 27 %, for 20 years of use of a data center with an installed IT- power of 1 MW, provided that the electricity price does not change significantly from today's market price. The district cooling technique was the most expensive and has disadvantages due to current energy tax policies, because district cooling suppliers are not entitled to tax subsidy. In this work, carbon dioxide emissions were assumed to be caused only by electricity used for cooling equipment. This resulted in that the heat pump with heat recovery was the best option for minimizing carbon dioxide emission. Recovering heat could furthermore reduce the carbon dioxide emission significantly, provided that the electricity was cleaner than district heating.