Solcellssystem med åtgärder för ökad egenanvändning av solel i fastigheter : Investeringsanalys av solcellssystem åt Rikshem AB

Sammanfattning: Rikshem AB is one of the leading private housing corporations in Sweden with an annual revenue of 2.8 billion. The company own close to 500 real estate properties with leasable area of 2.3 million square meters, mostly in larger cities from southern to northern Sweden. Rikshem have ambitious goals aiming to minimizing their environmental impact. Despite this, the knowledge about photovoltaic systems and its contribution to an emission free power production, is low within the company. Previously, photovoltaics hasn’t been an option for investment strategies at Rikshem, due to its high investment cost. In recent years the price for such systems has fallen and probability is easier reached due to many of Sweden’s economic incentives for photovoltaic systems. This thesis main goal was to create an investment model for Rikshem to use when determining the probability of a photovoltaic system. The model was to evaluate the suitability of PV-systems for different real estate properties with different profitability measurements, such as net present value, payback, internal rate of interest, life cycle cost and levelized coast of energy. Since the value of the self-consumed photovoltaic produced kilowatt-hour is more valuable than the one exported to the grid, a high self-consumption is important for good probability of a PVsystem. Therefore, three actions for improving the selfconsumption of photovoltaic electricity was considered in this thesis: energy storage in batteries, common grid connection and a DC-microgrid. This was evaluated through a case study of three real-estate properties with different activities. The probability of the different actions was determined with the investment model. The results from the case study shows that the most profitable action for increasing self-consumption is common grid connection, since it necessarily doesn’t mean an extra cost for Rikshem when implemented. Energy storage was the overall worst action, due to the high cost and short life time. Implementation of a DCmicrogrid generated good probability results for two of the three properties. It can be concluded that microgrids suits buildings differently and that the probability is mostly dependent of nearby buildings with high electricity demands.