Analysis of alternative back-up power source for a distribution centre

Abstract

Lindex distribution centre (Lindex DC) in Partille has a back-up power system with a diesel generator to power their servers in case of power failure. Since the servers’ power consumption has declined in recent years, their diesel generator is now oversized. An oversized diesel generator will run on low load which puts strain on the diesel engine and may result in problems in the future. In order to solve this problem, this case study compares different alternatives such as; connecting more equipment to the current diesel generator, selling the current generator and investing in a more optimized diesel generator, and selling the current generator and investing in a renewable energy source such as a fuel cell and/or solar power. The solar power could then be used to produce hydrogen gas via an electrolyser. In the latter alternative, the hydrogen is stored in a pressurised tank and can later be used with a fuel cell in case of a power failure. When the storage tank is full, the solar energy will instead provide the building with energy. If there is an overproduction of energy, it may be possible to sell the excess energy to a distributor. By investigating the consumption and documentation at Lindex DC, the consumption for the alternatives could be estimated. In the comparison between the alternatives, the authors chose to investigate availability, economy and environmental impact in order to evaluate the alternatives with a grading system. With these combined aspects, a fuel cell alternative received the highest grade.