Proven Best Practices to Improve PUE (Power Usage Effectiveness) in Data Centres

Energy efficiency is no longer optional for colocation data centre services operators. It now defines how well a colo data centre facility is run. Power prices are rising, regulations on sustainability are tightening, and workloads are only getting heavier. That combination leaves operators with little choice but to manage energy better. This is where Power Usage Effectiveness (PUE) comes in. It has become the yardstick for how well a facility is run, whether it’s a private enterprise site or a large colo data centre.

At STT GDC India, even small gains in PUE have shown real results - lower bills, better environmental performance, and customers who see efficiency as part of how we operate, not an afterthought. With more than 30 facilities across 10 cities, we run data centres in India that are reliable today and flexible enough for what comes next. In FY24, we improved our average PUE to 1.62 (from 1.65 in FY23), with all new builds designed for PUE below 1.5. These small but steady gains prove that efficiency is not a one-off initiative but a continuous discipline.

Over the last few years, we’ve introduced design principles that are focused on efficiency across our STT Global data centres India private limited colo data centre campuses. This includes optimising airflow layouts to adopting power units that scale with demand. While they’re tech upgrades, they also represent a shift toward building data centres in India that are both economically viable and environmentally responsible.

Understanding PUE and Why It Matters

Power Usage Effectiveness (PUE) measures how efficiently a data centre uses energy. The PUE calculation is simple enough:

PUE = Total Facility Energy ÷ IT Equipment Energy

In a perfect world, a score of 1.0 would mean that every single unit of energy powers servers and nothing else. No cooling, no lighting, no distribution losses. Of course, no real-world facility hits that, but the closer a PUE data centre gets, the better.

Why does this matter in practice? For operators, lower PUE means less money wasted on overhead expenses. For customers, it’s proof that the PUE data centre provider is cutting waste and investing in efficiency. And in a fast-growing market like data centres in India, efficiency often tips the scales when enterprises choose between different colocation data centre services. For BFSI customers, a lower PUE data centre translates into predictable costs, reliable uptime, and compliance with ESG mandates. For AI-driven enterprises, it ensures that high-density compute workloads run sustainably without compromising performance.

We look beyond a single PUE score. Every STT Global data centres India private limited site is measured against global benchmarks, then adjusted for India’s climate and grid conditions. That blend of global practice and local tuning is what makes efficiency gains last across a national footprint of over 30 facilities and close to 400 MW of capacity.

Ways to Improve PUE

1. Smarter Cooling Systems

Step inside a data centre in India and the first thing that hits you is the sound and the temperature. Cooling is the biggest consumer of power after the servers themselves, which is why any efficiency journey usually starts here. The real trick is not to flood the entire hall with cold air but to attack heat where it is created. At STT GDC India, we use a full mix of technologies - in-row systems, rear door heat exchangers, immersion, and direct-to-chip liquid cooling - each tuned to Indian operating conditions. The Pune Innovation Lab has taught us that you cannot just import methods from abroad and expect them to work. By testing cooling technologies locally before scaling, we only deploy what delivers under real workloads, saving both energy and spend.

These optimisations also contribute to significant water savings, with a 46.7% reduction in water usage since our FY21 baseline, highlighting the water–energy link in sustainable cooling.

2. Upgrade Power Infrastructure

Legacy power systems drain efficiency. Older UPS units waste energy in conversion, and static layouts keep equipment running even when demand doesn’t require it. The upgrade path is not expensive, but it pays off. At STT Global data centres India private limited, many campuses already run on high-efficiency UPS systems in eco-mode. Distribution has been redesigned into modular blocks so power scales up or down with need, not in fixed slabs. The next step is even smarter: pilots of AI-assisted UPS controls are underway to shift loads in real time, reducing waste while keeping resilience intact.

3. Make Energy Sources Work Harder

Cutting energy use is only part of the equation; where that energy comes from is just as important. Long-term renewable contracts and smarter procurement strategies give colo data centres both stability in cost and credibility in ESG reporting. At STT GDC India, more than 30% of our current energy mix comes from renewables, supported by long-term agreements that prove our progress. The plan is to raise that figure in line with India’s 2030 clean energy goals. Customers increasingly ask for verified ESG data, and being able to point to signed contracts and delivered megawatts turns ambition into trust.

This is part of our broader Carbon Neutrality by 2030 roadmap, ensuring that efficiency gains are locked into long-term sustainability goals.

4. Continuous Monitoring and Benchmarking

You cannot improve what you do not measure, and in a PUE data centre, guessing is expensive. Real-time monitoring tools show exactly where energy is being spent, while benchmarking highlights whether performance is leading or lagging. At STT GDC India, monitoring has moved far beyond record-keeping. Our systems tie directly into DCIM and IoT asset management platforms, giving operators a live view of power, cooling, and IT loads, and giving customers the same visibility in regular reports. Issues are picked up earlier, fixed faster, and tracked with the kind of transparency that proves efficiency is not just claimed but demonstrated.

5. Invest in People as Much as Technology

Technology sets the framework, but it is people who make it stick. Small routines - keeping hot-aisle layouts tight, placing equipment correctly, maintaining airflow discipline - have a compounding effect when followed every day. At STT GDC India, efficiency is embedded in our culture. Teams go through regular training, certifications, and daily checks that make energy discipline second nature. In our experience, this is what separates average colocation data centre services from market-leading ones: the ability to treat efficiency not as an initiative but as part of reliability itself.

PUE isn’t a one-time fix. It’s a habit, constant monitoring, small corrections, and bigger upgrades when they’re needed. Cooling, power, renewables, training, they all matter, though not always equally at the same time.

For customers, what matters with data centres in India is plain: costs they can predict and systems that stay online. That’s what we’re building toward at STT GDC India. As one of India’s leading colocation data centre operators, we back our AI-ready facilities with ongoing research at the Pune Innovation Lab. New ideas are tested, refined for Indian conditions, and scaled across our network.

For us, improving PUE isn’t only about today’s targets. It’s part of building the kind of infrastructure India’s digital economy needs, scalable, sustainable, and ready for the future. Recognition from sustainability frameworks and customer ESG scorecards further validates that PUE improvements are not just operational wins but a true competitive edge in India’s colocation data centre services industry.