Solar Energy and Free Cooling Potential in European Data Centers

Energy efficiency has become one of the key issues for data center operators in recent years. Significant power and consequent cost savings are perceived to be attainable and are also considered to be mandatory due to environmental aspects and for sustainable development. Use of economizers and free cooling is currently one the most prominent ways to make data centers more efficient. Besides efficiency, solutions for green energy production are becoming more and more of a reality and while providing clean energy, intermittency is a considerable challenge, not least due to high reliability requirements in data centers. Solar energy, while currently being somewhat uneconomical solution, is expected to increase in the future with improved and cost-effective photovoltaic systems and due to its significant potential surpassing all the other renewable sources combined. Solar energy also has to a certain extent, when compared with e.g. wind energy, a more predictable pattern. It also correlates with temperature, making it an attractive source for systems in which power consumption is temperature related, such as with data center cooling. Unfortunately, locations with high solar energy production potential are somewhat less optimal for economizers and free cooling. This paper investigates basic relationships between solar energy and air temperature and subsequent data center cooling requirements. Of particular interest is the optimal data center location in terms of free cooling and solar energy potential. c © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [name organizer]