Key focuses for the creation of a future sustainable digital infrastructure

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The digital industry, responsible for four per cent of the entire global carbon footprint, has a major role to play in adopting sustainable solutions to eradicate greenhouse gas emissions, paving the way to a net-zero future. Of that four per cent, 30 per cent can be accounted for by data centres, which use huge amounts of energy to store various forms of data.

Given that the outlook for our future includes a reliance on digital infrastructure, it is necessary to compel this infrastructure to adhere to climate control and net-zero initiatives essential to prevent global warming. While there is a rising consciousness around this issue from data centre stakeholders and clients, some service providers have had this ethos baked into their business model from the beginning.

Blending technology with social and environmental care is part of Qarnot’s DNA, with the focus firmly on the two founding motivations of the company: technical complexity and sustainable goals.

“I believe consistency is the key, and that is why it is important that social and environmental care is reflected in every aspect of the company,” says Nicolas Saintherant, director of innovation at Qarnot.

With the advent of a decentralised IT structure, among many other innovations they have made since, this outlook has served Qarnot well so far, and is set to continue to do so moving forward.

Decentralising IT infrastructure to increase sustainability

Qarnot’s concept of decentralisation began ten years ago, when their founder, Paul Benoit, observed that if you put several computers in the same room, they give off heat that is either completely wasted, or must be cooled off.

“That is how he got this very innovative idea to recover the heat and turn it in to a valuable resource that heats buildings. But transporting heat without losing it, and at a reasonable cost, is a difficult challenge,” Saintherant, continues. “It is easier to transport data comparatively. It became obvious that the optimisation of the system would rely on the fact that the heat should be used where it is produced, and to do so you must bring the infrastructure in to buildings and distribute it. That’s how you get a decentralised IT infrastructure.”

There are multiple advantages in embedding microprocessors into air or water heating devices in this way, including the recovery of up to 100 per cent of the waste heat and generating a single carbon footprint from two uses – both computing and heating.

“By turning waste in to a valuable resource we have a digital circular economy approach that is profitable to everybody. Our cloud computing clients benefit from very competitive rates as our infrastructure is financed by the landlords and real estate developers who buy the heating devices, and people equipped with our boilers and heaters benefit from free heating as we reimburse their electricity bill. And of course, on top of that financial benefit comes the energy savings and carbon footprint decrease for all stakeholders.”

Measuring data centre performance

The original use of the term Power Usage Effectiveness (PUE) was based upon the power drawn by the IT equipment, the power drawn by the cooling equipment, and the power losses in the electrical distribution system, hence the name Power Usage Effectiveness. Power is generally assigned units in kilowatts and it represents an instantaneous measurement or snapshot in time of the power use. Electrical Energy (kWh) is the product of power (KW) times duration that it is applied (hours), so the units of energy would typically be kilowatt-hours. If a server with a power draw of 20 kilowatts drew exactly that much power for an hour, it would have used 20 kW-hrs of energy. Power is an instantaneous measurement, while energy is an integral over time. Typically, we are more interested in energy, but both have an important function in the design and operation of any data centre. The simplicity of the PUE metric allows the mathematics to be valid and consistent for either power or energy.

Alternative concepts, such as energy reuse effectiveness (ERE), have given data centres an opportunity to be energy suppliers, not just users. Data centres have already made tremendous sustainability strides over the last decades with significant reductions in both PUE and WUE. Therefore, waste heat utilisation is just one more important step for data center operators to reach a future net-zero energy goal.

“It is commonly admitted that you cannot reach an objective that is not measurable,” Saintherant explains. “So, it is a good thing that the data centre industry adopts metrics and the PUE is one of them. But we believe that, even though this indicator gives an overall idea of the energy efficiency of data centres, it does not consider the energy that is reused as the ERE does.

“In a way, the PUE enables you to achieve half of the objective of measuring efficiency, and the ERE helps achieve the second half. The best PUE you can reach is 1, meaning that all the consumption of the data center is the one of the IT equipment, whereas the best ERE you can reach is 0, meaning that all the energy is reused. If you look at both indicators, then you realise that the greener infrastructure is not always the one you thought it would be.

“For example, a data centre with a PUE of 1.5 and an ERE of 0.6 is more efficient than one with a PUE of 1.2 and an ERE of 1.2. So, the PUE cannot be the only metrics, and combining different approaches is the only way to raise the general level of our industry and get a clearer understanding of what sustainability really is all about beyond buzz words and big announcements.”

Maintaining grid stability

Beyond system optimisation, there are several other considerations to be made when outlining a data centre’s sustainability credentials. As the number of data centres continues to grow, it puts great pressure on an often already under pressure power grid. Integrating a data centre into smart grids, while avoiding unbalancing the existing grid, is a key priority.

In answer to this, Qarnot have been involved in the Catalyst project, an EU funded initiative which aspires to turn data centres into flexible, multi-energy hubs which can sustain investments in renewable energy sources and energy efficiency. Their role in heat recovery meant they were particularly involved in the demand response questions concerning electricity and heat, as well as the migration of virtual machines to control electrical consumption or heat production.

For Qarnot’s own distributed model for data centres, balancing the grid remains easy because unlike traditional data centres, their sites do not over-allocate electricity for themselves.

“Data centres need to forecast the maximum electricity they will need, even before all the servers are installed, which can create potential problems if the grid is already under stress or arbitrations need to be made,” notes Saintherant. “Our collection of small sites is just like a collection of individual clients for the energy provider, which means we don’t contribute to unbalancing the grid.”

Other key sustainability issues

While energy is the focus in driving sustainability in data centres, the utilisation of space is also a crucial factor. Data centres that are built to meet the highest energy efficiency standards often occupy massive amounts of space, which itself is part of the carbon footprint of the building. For example, the largest data centre in the world is currently being built in Norway, which will occupy roughly 600,000 square metres of land.

Another consideration is in the product lifecycle of the materials and equipment needed to run a data centre. Within these vast spaces, data centres require trenches for cables, concrete floor slabs, machines to be empowered, batteries for redundancy, and tonnes of construction materials, all created in carbon intensive industries.

With the adoption of space saving measures and control over the whole supply chain for materials, from the manufacturing process to their end of life, Qarnot are standing by their commitment to ensure sustainability is their number one priority.

In a digital future which is at the forefront of green energy and technology innovations, there is plenty to feel optimistic about. Research and development remain key areas of investment for Qarnot, and they are already working on several projects to improve their boiler systems and increase the scalability of their products. They are also working with a think tank to find an accurate way to measure the carbon footprint of cloud computing. All this means they are well placed to take advantage of the possibilities presented to them by a net-zero future.

“Our solutions bring answers to the challenges presented by cloud computing and sustainability,” concludes Saintherant. “We are very confident that our efforts to pioneer cutting-edge technology with low-carbon impact is what is needed right now, and we are ready for it.”