Through emissions of carbon dioxide and other greenhouse gases, humans have been a contributing factor to the increase in the average temperature on earth. The Swedish government has set a national climate target to reduce the emissions of greenhouse gases and have zero net emissions by 2045 in order to live up to the requirements state in the Paris Agreement. To be able to reach these goals, more renewable energy is needed to meet the power needs that exists in society as well as reduced emissions in connection with the construction sector. Right now Slussen in Stockholm is currently undergoing reconstruction to ensure above all else two major things. That no salt water seeps into the fresh water in Mälaren in order to secure drinking water for approximately two million people and to be able to drain larger amounts of water from Mälaren to minimize the risk of flooding the surroundings of Mälaren. This means that the flow of water from Mälaren to Saltsjön will occasionally be very high.

This thesis examines the possibilities of installing hydropower at Slussen, from both a technical perspective as well as an economic perspective where two different types of turbines are considered. One is a StraFlo-turbine, a sort of Kaplan turbine, and the other is a vertical axis water turbine. Based on the water flow from the past five years, calculations have been made on how much power the two different turbines could generate under the given circumstances.

The result shows that the StraFlo-turbine can potentially generate significantly more power than the vertical axis water turbine at a medium flow rate. The StraFlo-turbine would more than cover the facility’s power needs for the hatches and the draw bridges during the majority of the year, something the vertical axis turbine would have problems with. Although the investment cost of the StraFlo-turbine is significantly higher, the payback period is shorter.