Increases in electricity prices in Sweden during the second half of 2021 have created a great deal of concern among companies in Sweden. Some companies report that they have stopped their production temporarily when electricity prices have been high. Several of the companies also report that future investments have been stopped and some of the companies also state that they have or are planning to move their production abroad. One of the companies that has been affected by the increased electricity prices is an SME (Small Medium Enterprise) company located in electricity area 2 in Sweden. This has caused the company to evaluate different alternatives to be able to lower their costs linked to their electricity consumption. One of the options that is being evaluated is to invest in a solar (photo voltaic) cell, a technology that has become significantly cheaper over time and solar cells installations have increased a lot in Sweden recent years.

The purpose of this study is to help the company evaluate whether it is a good option or not to install a solar cells system. The perception within the company is that the price for purchasing electricity is higher than what they would earn from selling the electricity. Therefore, the company wants to install a solar cells system which has a high proportion of self-consumption. But is that view true and, if so, to what extent and how could a solar cells system be designed to optimize self-consumption?

The result shows that by tilting and turning the solar cell panels, it is possible to change the time for production and the amount of electricity produced from a solar power system. In the current case for this study, electrical consumption is at its highest during working hours 07.00-16.00. It is also during this time of the day the solar radiation is at its most intense and the solar cells system can produce as efficiently as possible. Results showed that it was not profitable to increase self-consumption by turning and tilting the solar panels so that they produced less during the holiday season and more during other parts of the year. The view that self-consumption would increase profitability proved correct and it turned out that a smaller solar plant system is more profitable until the point that the installed power per SEK increased.

The conclusion of the work is based on the results of the best-designed solar cells system based on installation costs, previous electricity consumption, forecasted electricity prices and current STIBOR rate. The pay-off time for this solar cell system would be 8.6 years and 15.6 years discounted pay-off time. Which may certainly seem like a bad investment and therefore, one might wonder why so many solar cell plants are installed in Sweden. This can largely be explained that from 2020 there are no subsidies for the installation to apply for companies. The company is also not entitled to a tax reduction that gives 0.60 SEK for each kWh sold. This is because their main fuse exceeds the limit of 100A, which is above the limit according to one of the Swedish tax agency requirements for obtaining the tax reduction.