Researchers from Trinity College Dublin are aiming to develop tools and methods that enhance the integration of the Irish energy system in order to deliver reliable, cost-effective energy services with less impact on the environment.
The researchers are part of a large SFI-funded project, ‘Energy System Integration Partnership Programme’ (ESIPP), in which 13 Schools from five Irish universities collaborate with industry partners such as EirGrid, ESB, and a range of other collaborators including Interxion. The team, headed by Dr Tim Persoons in Trinity’s Department of Mechanical & Manufacturing Engineering, which is working with Interxion focuses specifically on more sustainable thermal management of data centres.
Due to the increasing demand for IT services, such as real-time processing, online transactions, social media and so on, the requirement for data storage and computation has been rising exponentially over the past decade. Data is typically stored on computer servers in data centres. These are facilities designed to provide reliable and undisrupted power supply and data transmission, and to assure the required environmental conditions for the integrity of the servers thanks to the presence of air conditioning units and cooling systems.
Data centre electricity demand has seen a yearly increase of about 11% worldwide between 2000 and 2010. In Ireland, in 2018, data centre electricity consumption was approximately 500 MW or 12% of the national electricity demand, which is expected to rise to 31% by 2027 according to Eirgrid’s Generation Capacity Statement.
In a typical data centre, IT equipment uses around 50% of the total energy, while thermal management uses around 30% for cooling infrastructures. All of the energy consumed in computing equipment is ultimately transformed into heat that cannot be repurposed or reused. Dr Persoons said: “In this context, our aim is to research advanced cooling technologies that are less energy demanding and investigate the feasibility of recovering waste heat for uses such as water and district heating. This research is carried out considering both the economic and engineering perspectives.”
The work involves Dr Eleanor Denny and PhD researcher Bryan Coyne from Trinity’s Department of Economics, and Dr Persoons, Dr Assel Sakanova, Dr Sara Battaglioli, and PhD researcher Jaakko McEvoy, along with Dr Nicolas Baudin and Master’s students, Brian Long and Eoin Oude Essink.
Currently, part of the engineering team is focusing on how to optimise a typical data centre server, for example by changing the internal layout of its components or offering retrofit solutions such as the inclusion of three-dimensional baffles to guide the air flow through the server, in order to reduce energy consumption while maximising the potential for heat recovery.
In a typical server, air flows from the front to the back to cool components such as CPUs and RAMs, which must operate below a specific temperature. Hot air is expelled from the back of the server, but usually under conditions that make it impractical to recover useful energy from it. In order to optimise heat recovery with specialised heat exchangers, the outlet air temperature should be both high and as constant as possible.
To identify possible strategies for this task, a general server is analysed by combining computational fluid dynamics (CFD) models with an optimisation method called multi-objective genetic algorithm (MOGA). These models require the knowledge of accurate data, such as thermal and power cycling of a typical server, which are not available in the scientific literature and hence need to be collected in actual working data centre rooms in order to make sure that realistic simulation parameters are used.
Dr Persoons added: “For this reason, our team is currently collaborating with Interxion, a data centre colocation company with more than 50 data centres in Europe—three of which are located in Dublin. With the help of their Irish management team, including Tanya Duncan, Karl Mulhall, Ben Robinson and project engineer Mark Boland, our team was able to access one of their state-of-the-art data centre rooms to collect the information necessary for our research.”
Speaking about its participation, Tanya Duncan, MD of Interxion in Ireland said: “As a European provider of colocation services, Interxion is focused on maximising its energy efficiency and utilising renewable energy. We continue to introduce innovative technologies and design practices across our sites in Ireland so it was a great opportunity to work with the team in Trinity College Dublin to look at new ways of reducing our energy usage.”