Konvertering från direktverkande el i kommersiella lokaler : Ekonomisk och hållbar utveckling

Sammanfattning: Buildings worldwide account for 40 % of the total energy use. Climate change is of increasing importance, but few are willing to reduce their standard of living or get a higher cost for the change. Energy efficiency of existing buildings gives the greatest benefit economically and environmentally.   The real estate company Klövern AB manages 46 properties in Karlstad. Heating is the major cost of the total operating costs of real estate. Rising energy prices increase the need for Klövern AB to improve energy efficiency and to investigate alternative sources of heat. The report's purpose is to explore alternative sources of heat for Hammaren 21, one of Klövern's properties that currently have direct electricity. A new system is investigated from an economic and sustainability aspect. The goal is to present a result that can be used as a basis for future investments to Klövern AB.   The economic analysis is done by calculating the total cost over 20 years with an LCC (Life Cycle Cost) in present value. This calculation is done by using three possible scenarios, where the discount rate, inflation and price rise of energy are varied from a normal case, which is considered as the most likely, and a low and a high price trend.   Sustainability analyzes the carbon impact and resource consumption with resect of MWh fuel.   The total energy demand for heating the properties is 231 000 kWh / year, which corresponds to 119 kWh / m2. The cost of heating and hot water is 206 000 SEK / year. District heating has a lower investment cost and a higher annual cost compared with geothermal heating, which has reversed costs.   The most economical option is to install geothermal heating, with one heat pump per property. It provides an annual saving of 76% of operating costs, and total savings during 20 years from 1 000 000 SEK to 2 920 000 SEK. Geothermal heating can also be used to cool the premises. Installation of district heating gives annual savings of 39% of operating costs and total cost savings over 20 years from  780 000 SEK to 1 830 000 SEK.  Pay-off for district heating is 4 years and for geothermal 7 years.   District heating is the best choice from a sustainability aspect. District heating gives reduced carbon emissions of 203 tons of CO2 / year and a reduction in resource consumption by 481 MWh of fuel. The corresponding figures for geothermal heating are 173 tons of CO2 / year and 421 MWh of fuel.