Green Data Centres in Australia: How to Check the Claims

Why green claims deserve a closer look

Sustainability has moved from a nice-to-have to a procurement requirement for many Australian businesses. Your board may have emissions targets, your customers may ask about your supply chain, and if you work with the Australian Government, energy ratings can be a formal requirement. Data centres are energy-hungry, so the facility you choose can make a real difference to your reported footprint.

The trouble is that nearly every operator describes itself as green, efficient or sustainable. Some of those claims rest on measured, independently rated performance. Others rest on design targets, purchased certificates or carefully chosen wording. This guide explains the main measures, what to ask for, and the warning signs to look out for.

PUE: useful, but only if it is measured

Power Usage Effectiveness (PUE) is the most common efficiency metric. It is the total energy used by a facility divided by the energy used by the IT equipment. A PUE of 1.0 would mean every unit of energy goes to IT equipment; anything above that is overhead for cooling, power conversion, lighting and so on. Lower is better.

PUE is helpful, but it is easy to present in a flattering way. When an operator quotes a PUE, ask:

• Is this a design PUE or a measured, operational PUE? • Over what period was it measured? A full year captures summer cooling loads; a single cool month does not. • Does it apply to the specific building and hall I would occupy, or to the operator's best site? • At what load level? A half-empty hall can behave very differently from a full one.

A design PUE tells you what the engineers aimed for. An annualised, measured PUE for your building tells you what actually happens.

NABERS: Australia's independent rating

NABERS (the National Australian Built Environment Rating System) is a national government initiative that rates the environmental performance of buildings, including data centres. NABERS Energy for Data Centres gives a rating from one to six stars based on the facility's actual operational data, not its design, using PUE as the underlying measure. Ratings are carried out by NABERS accredited assessors and are renewed annually.

There are three types of data centre rating:

• IT Equipment, for organisations that manage their own IT equipment but not the facility's cooling and other support services. • Infrastructure, for owners and operators that provide the power and cooling to tenants' equipment. This is the rating most relevant to colocation facilities. • Whole Facility, which combines the two, for organisations that both run and occupy a data centre.

For a colocation buyer, the useful question is simple: does this specific facility hold a current NABERS Energy for Data Centres Infrastructure rating, and how many stars? Ask to see the certificate and check that it covers the building you would be in and is still current.

NABERS also carries weight in government procurement. Under the Australian Government's Net Zero in Government Operations Strategy, providers on the Digital Transformation Agency's Data Centre Panel need a 5-star NABERS Energy for Data Centres rating or an equivalent environmental rating, and the strategy extends a 5-star (or equivalent) expectation to new Commonwealth data centre facilities sourced outside the panel from 1 July 2025. Requirements can change, so if you are bidding for government work, confirm the current rules with the relevant agency.

Renewable energy: PPAs versus certificates

Many operators say they run on renewable energy. There are different ways to back that claim, and they are not equal.

Power purchase agreements (PPAs). A PPA is a long-term contract to buy electricity, or the environmental attributes of electricity, from a specific renewable project such as a wind or solar farm. PPAs can help bring new generation into the grid, especially when they underwrite a project that would not otherwise be built.

Renewable energy certificates. In Australia, Large-scale Generation Certificates (LGCs) represent renewable electricity that has been generated. Buying and surrendering certificates is a legitimate way to account for renewable electricity, but buying certificates alone may not add new generation in the way a long-term PPA can.

Accredited GreenPower. Some operators buy GreenPower through their retailer, which is another accredited way to match consumption with renewable generation.

On-site generation. Rooftop solar is welcome but usually covers only a small share of a data centre's demand.

None of these is automatically bad. The point is to know which one is behind a claim. Ask what share of the facility's electricity is matched by renewable sources, by which mechanism, over what period, and whether certificates are surrendered on the customer's behalf so you can include them in your own reporting.

Red flags in sustainability marketing

Watch for these patterns:

• A PUE figure with no date, period or building attached. • "Up to" or "designed for" language with no operational data. • "Carbon neutral" claims that do not explain what was offset, how, or whether a recognised certification sits behind them. • Renewable claims that apply to the company's offices or one flagship site, not the building you are buying into. • No NABERS rating, and no explanation of why not, for an established Australian facility. • Reluctance to give you the energy and emissions data you need for your own reporting.

A newly opened facility may not yet have a year of operational data to rate, which is fair. In that case, ask when it expects its first rating and what target it is working towards.

A buyer questionnaire you can send

Copy these questions into your request for proposal:

1. Does the facility hold a current NABERS Energy for Data Centres rating? Which type, how many stars, and when does it expire? 2. What was the measured annual PUE for this building over the last 12 months? 3. What percentage of the facility's electricity is matched with renewable sources, and by which mechanism (PPA, LGCs, GreenPower, on-site)? 4. Can you provide monthly energy data for our deployment for our emissions reporting? 5. What cooling technology does the hall use, and how is water use managed? 6. What is your published roadmap or target for emissions reduction? 7. Is there any independent certification or audit behind your sustainability claims?

Use the comparison tool (/compare) to record answers side by side, and look up operators in the provider directory (/providers). For background on cooling and power, browse the learning centre (/learn).

Ready to narrow it down?

Sustainability is one factor among several, alongside location, power, resilience and price. DChunt's free assessment (/assessment) lets you flag sustainability and compliance needs so the operators on your shortlist are ones that can back up their claims. DChunt is independent and does not resell data centre space.