Uppsala is growing at a fast rate and todays powergrid cannot support the increase in population hence the power grid must be relieved. We can accomplish this through peak shaving.  The mobility house Dansmästaren in Rosendal was built with the purpose of serving as a test bed for technical systems that have the task of relieving the power grid. It does this by applying the peak shaving technique to reduce the energy use, which mainly comes from the electric car chargers that is in Dansmästaren. Uppsala Parkering AB (UPAB), which runs Dansmästren is currently building a second mobility house in Rosendal called Brandmästaren. This report presents a comprehensive analysis of what kind of energy storage system Brandmästaren should have to streamline it's peak shaving.  The results showed that there are many ways to improve the energy storage system. But a detailed cost estimate is needed to know which of the alternatives is the most cost-effective.