Energy storage in households and substations : A study focusing on how energy storage systems can be applied in households and substations, and what effects it will have on peak- power and the power usage over time

The present powergrid is currently undergoing a modernization, developing into a smarter grid with more and more renewable energy sources being connected every day. To successfully manage to fully liquidate the use of fossil energy and nuclear power, it’s demanded by their successors to keep the same reliability and capacity. Energy storage systems can play a great role in enabling this transition, partially to decrease the losses on the power grid but also to maintain the reliability and increase the flexibility. This study has been conducted with the main focus on load leveling households and substations, but also to locate which applications an energy storage system may have in the future and explain the benefits and disadvantages that rises from it. This study also presents a survey on different kinds of battery technology and the future of batteries. Simulations have been carried out on load leveling with energy storage system in households and substations. The simulations on households have been carried out both with and without power input from solar panels. The data is taken from Hållbara Ålidhem, substations Masten, Ön norra, Tomten and Valfisken. Data from four different households in Umeå has been used to act as an average household to conduct economical calculations on load leveling with an energy storage system. The study also presents a theoretical chapter, discussion and examples of optimizing dimensions of an energy storage system with solar panels, the financial aids and the laws and regulations of energy storage systems. The simulations indicate that regardless of the size of the energy storage system improvements can be made, provided an efficient power control. The improvement found from the simulations are reduced peak-power bought from the grid, and in the real world installing an energy storage system would also mean decreasing electrical losses. The simulations also indicates that the maximal power peaks over the household or substation can be reduced with the maximum output power from the energy storage system, provided an efficient power control. The most important factor in optimizing an energy storage system is considered to be the control of input and output power from the batteries. The economical calculations indicate that in the current situation there are no economic benefits from investing in an energy storage system as a private householder, but the study also presents different scenarios where an energy storage system could have an economic benefit over its lifespan.