Simulation and implementation of strategies to control energy flow through a BESS

Abstract

This report discusses different strategies for charging and discharging a battery energy storage system to maximize economic profit. The work is based on the Swedish energy market. Three strategies are evaluated, first the output minimizing strategy attempting to minimize the output energy toward the electric grid, second the peak reduction strategy attempting to minimize the maximum power consumption by discharging the BESS during peak hours and charging at night time when prices are low, and third the floating zero strategy trying to keep the output toward the grid at a certain level based on the local consumption profile. Simulations show that in an ordinary household the suggested output minimizing strategy saves 2994 kr yearly for a 12 kWh BESS, 3583 kr for a 24 kWh BESS and 3887 kr for a 48 kWh BESS. The peak reduction strategy saves 2447 kr yearly for a 12 kWh BESS, 2853 kr for a 24 kWh BESS and 2960 kr for a 48 kWh BESS. The floating zero strategy saves 2375 kr yearly for a 12 kWh BESS, 3196 kr for a 24 kWh BESS and 3538 kr for a 48 kWh BESS. Numbers are based on current energy cost and consumption for an ordinary household and result in a pay off time of approximately 25 years or greater, depending on system size.