As the digital landscape evolves, data centres have become the backbone of our online activities, supporting everything from cloud computing to e-commerce. However, they are also among the most energy-intensive facilities globally. 

At CES, we assist data centres in reducing energy costs and environmental impact without compromising reliability. Here’s our guide to enhancing energy efficiency in data centres. 

Why Energy Efficiency Matters 

According to the International Energy Agency report, in 2022, data centres, cryptocurrencies, and artificial intelligence (AI) consumed approximately 460 TWh of electricity worldwide in 2022, almost 2% of total global electricity demand. This figure is projected to double by 2026, potentially exceeding 1,000 TWh, underscoring the critical need for energy efficiency in data centre operations as AI and digitalisation rapidly expand demand.1 

Notes: Includes traditional data centres, dedicated AI data centres, and cryptocurrency consumption; excludes demand from data transmission networks. The base case scenario has been used in the overall forecast in this report. Low and high case scenarios reflect the uncertainties in the pace of deployment and efficiency gains amid future technological developments.

Sources: Joule (2023), de Vries, The growing energy footprint of AI; CCRI Indices (carbon-ratings.com); The Guardian, Use of AI to reduce data centre energy use; Motors in data centres; The Royal Society, The future of computing beyond Moore’s Law; Ireland Central Statistics Office, Data Centres electricity consumption 2022; and Danish Energy Agency, Denmark’s energy and climate outlook 2018.

Source:  https://iea.blob.core.windows.net/assets/6b2fd954-2017-408e-bf08-952fdd62118a/Electricity2024-Analysisandforecastto2026.pdf 

Improving data centre energy efficiency reduces environmental impact, enhances uptime, lowers operating costs, and aligns data centres with Net Zero goals. 

1. Understand and Optimise Your PUE

Power Usage Effectiveness (PUE) measures how efficiently a data centre uses energy. It’s calculated by dividing the total energy consumed by the entire facility by the energy used directly for computing equipment.2 

Power Usage Effectiveness (PUE) is the industry-standard metric for efficiency: 

PUE = Total Facility Energy / IT Equipment Energy 

• 1.0 = Ideal (all energy goes to computing) 

• 1.2 = Very Efficient (typical for new, well-managed centres) 

• 1.8 = Average in the UK 

 Start by conducting an energy audit to identify energy drains, measure baseline PUE, and set improvement goals. 

2. Strengthen your Energy Management Strategy with Proactive Energy Procurement

 Strategic electricity procurement is crucial in managing energy costs and enabling future energy efficiency investments. 

With market prices and third-party charges in constant flux, a well-planned procurement approach can help stabilise costs, freeing up resources to invest in operational improvements. Timing energy purchases to coincide with market dips, choosing between fixed or flexible contracts, and forecasting future costs are all essential levers. 

Strategic energy procurement can also include low-carbon options, such as REGO-backed electricity or long-term Power Purchase Agreements (PPAs) to support broader sustainability or carbon reduction goals. With the right support, these commercial choices can be integrated into a broader energy management strategy. 

3. Best Practices for Cooling and Containment

 Cooling is one of the most significant energy expenditures in data centres. Best practices include: 

• Hot & Cold Aisle Containment: Align server racks to create separate aisles for hot and cold air. This minimises the mixing of airflows and allows cooling systems to work more efficiently. Separating hot and cold airflows can reduce energy use by up to 25%. 

• Cold Aisle Containment Systems (CACS): Encloses the cold aisle using doors and ceiling panels. It uses the rest of the room as a hot-air return zone. This is widely used in raised-floor designs. 

• Ducted Hot Aisle Containment (HACS): Captures hot air using ceiling ducting, especially suitable for high-density environments or retrofits. 

• Rack Air Containment Systems (RACS): Provide full containment at the rack level, ideal for mixed-density environments and multi-client setups. 

• Computer Room Air Conditioning (CRAC): Drawing in warm air from the data centre, cooling it down, and then circulating the cooled air back into the room.

4. Adjust Temperature Setpoints

 Many data centres operate at cooler temperatures than necessary. Raising the intake temperature by just 1°C can yield significant energy savings.  

ASHRAE recommends: 

• Temperature: 18–27°C 

• Humidity: 8–60% 

 Setpoints should align with equipment specifications and be monitored with remote sensing. Use environmental sensors and adjust temperature settings based on actual performance, not outdated habits.  

5. Upgrade Legacy Infrastructure

 Old or redundant equipment can consume energy without delivering performance — and often increases maintenance risks. 

 Recommendations: 

• Replace redundant or underutilised servers. 

• Replace outdated equipment with Energy Star-certified hardware or blade servers, which provide greater performance in a smaller footprint. 

• Upgrade to high-efficiency UPS systems, LED lighting with sensors, and variable-speed fans to reduce power losses and heat generation. 

This not only saves energy but also creates space for future scaling. 

6. Leverage Smart Monitoring and Controls

 It’s impossible to manage what you can’t measure without proper monitoring. 

• Install submeters for different zones, equipment groups, and power distribution units (PDUs) to identify energy hotspots. 

• Monitor cooling loads, environmental data, and IT power usage in real time to support predictive maintenance and capacity planning. 

Smart monitoring turns passive data into actionable insights that drive continuous improvement. 

7. Explore Onsite Renewable Energy

Generating power onsite can protect you from volatile energy markets and reduce emissions. 

• Install rooftop solar panels or consider wind turbines where feasible. 

• Waste heat recovery systems can be used to repurpose excess heat for nearby offices or buildings. 

• Battery storage should be considered to manage intermittent generation and improve resilience. 

Some data centres can move toward 100% renewable energy consumption with a combination of technologies. 

8. Design with Flexibility and Sustainability in Mind

Whether you’re building a new facility or upgrading an old one, thoughtful design is essential: 

• Ensure raised floor plenums are at least 500mm deep to allow adequate cold air distribution. 

• Use cable management systems to prevent airflow blockages under raised floors or above racks. 

• Design for modular scalability, allowing the addition of power and cooling infrastructure as needed. 

• Plan for redundancy without inefficiency — avoid the trap of oversizing infrastructure. 

• Include sustainability in the brief: energy-efficient chillers, motion-sensing LED lights, and low-carbon construction materials all contribute to long-term impact. 

A future-ready data centre can adapt, expand, and stay efficient over time. 

Data centres are at the heart of the digital economy. With smart design, modern technology, and the right partners, you can boost performance while cutting carbon and cost. 

How can CES help? 

• Energy procurement strategies to optimise market dip buying  

• Bill validation including forensic audits and rebates  

• Budgeting including third-party charges forecast  

• Brokering REGO certificates below supplier cost  

• Sourcing and sleaving PPA (Power Purchase Agreement)  

• Administrating Climate Change Agreements (CCA)  

Need help identifying energy savings opportunities? 

Contact CES today at [email protected] to explore procurement and bill validation solutions that support a more efficient and sustainable data centre. 

References: 

1-  https://iea.blob.core.windows.net/assets/6b2fd954-2017-408e-bf08-952fdd62118a/Electricity2024-Analysisandforecastto2026.pdf 

2- https://www.datacentre-uk.com/a-guide-to-cooling-technologies-in-the-data-centre/