Data Centres and the Water-Energy Nexus: Challenges in Ireland

Ireland’s digital infrastructure continues to grow, but with it comes increasing concern about the environmental impact of data centres. The recent rejection of Google’s plans for a new facility due to concerns around water and energy consumption underscores the urgency for more sustainable solutions. Cooling systems, in particular, can rely heavily on energy and water - posing significant challenges.

Key Solutions for Water and Energy Management

Air-Cooled Systems

How Air Cooling Systems Work in Data Centers

1. Air Circulation: Cooling systems ensure continuous air movement within the data hall. Heat generated by IT equipment is either expelled from the data hall and replaced with fresh, cool air, or the warm air is routed back to an internal cooling system for temperature regulation.

2. Air Cooling:

Using Outside Air: When external air is utilised, it is conditioned to maintain optimal temperature and humidity levels before entering the data hall.

Recirculating Internal Air: In systems that reuse air within the data hall, the warm air is directed over cooling coils to dissipate heat efficiently.

Reducing reliance on water has never been more relevant. Air-cooled systems provide an efficient, sustainable alternative, lowering both environmental impact and operational costs. As the AI sector continues to expand rapidly, the development of new liquid cooling technologies and the growing acceptance of nuclear energy (particularly small modular reactors) offer promising sustainable solutions for the future. However, it remains crucial to focus on reducing the energy & water demands of data centres and adopting sustainable practices to enhance efficiency.

Hybrid Cooling Technologies

Hybrid cooling systems integrate both air and liquid cooling technologies, offering a versatile and efficient solution for managing heat in data centres.

1. Seamless Adaptability: These systems dynamically transition between air and liquid cooling based on real-time cooling needs, ensuring optimal performance and energy efficiency.

2. Air Cooling Role: Air cooling is typically used for maintaining overall temperature stability in the data hall and cooling IT equipment with lower heat densities.

3. Liquid Cooling Role: Liquid cooling targets high-density heat sources, providing intensive cooling for specific components or areas with significant heat output.

Hybrid Cooling Systems in Data Centers

Hybrid systems, which use water only during extreme heat, present a balanced approach. These technologies drastically reduce water consumption while maintaining the high performance needed for data centres. In Ireland, over 80 data centres account for 21% of the country’s electricity consumption - 16 times the global average of approximately 1.3%. The country’s temperate climate makes it ideal for adiabatic cooling, which can use up to 80% less water compared to traditional evaporative cooling systems.

Adiabatic Cooling

Adiabatic cooling works by leveraging the principles of evaporative cooling. This method involves utilising water to absorb heat from the air, thereby reducing the temperature without the need for mechanical refrigeration. In adiabatic cooling systems, air passes through pre-cooling pads that are moistened with water. As the air flows through these pads, the water evaporates, cooling the air before it enters the data centre. This process is highly efficient, especially in temperate climates like Ireland’s, where the ambient air temperature is moderate.

Exploring Alternative Water Saving Solutions

Leveraging rainwater and non-potable water for cooling is becoming important, particularly in water-sensitive regions. This reduces the burden on local resources while ensuring efficient operations. On-site water recycling allows facilities to reuse water, cutting down on external water usage and enhancing sustainability.

On-site water recycling allows facilities to reuse water, cutting down on external water usage and making operations more sustainable.

Smarter Design for Future Resilience

Good design is at the core of sustainable data centres. From strategic site selection to natural cooling features, future-proofing starts at the design phase, minimising environmental impact from the outset. ASHRAE standard 90.1 allows data centres in northern climates to draw cool air directly into data centres reducing energy demand. Ireland is well suited to this as the outdoor temperature is below 12°C approximately 66% of the time.

The Path Forward

As digital infrastructure develops, so does the need for sustainable solutions. By focusing on water management and energy efficiency, companies can future-proof their data centres and reduce their environmental impact. At Metec, we are leading the way in sustainable building design which requires foresight, innovation, and a commitment to smarter resource use.