As Europe braces for a winter of blackouts and gas shortages, thousands of Europeans are expected to die amidst frigid temperatures and the inexorable rise in energy prices as a direct consequence of the volatile situation on the continent caused by Russia’s president Vladimir Putin’s invasion of Ukraine. With fuel poverty quickly becoming the number one priority of governments across the region, part of the solution could lie within data centres themselves.
All the electricity input to the IT-equipment installed in a data centre facility turns into heat, and the heat needs to be cooled down in order for the equipment to function properly. Usually, this heat is cooled off in cooling towers or similar, instead of being utilised.
However, if there are heating demands in other parts of the building, neighbouring buildings or a district heating network that can take care of the heat, this heat can be used instead of wasted.
The temperature of the heat is often low, but if higher temperatures are needed a heat pump can be used to raise the temperature.
According to European Project CELSIUS, an energy transition group supported by the Swedish Energy Agency and funded by the European Union, the air leaving the hot aisles often has temperatures of about 25 – 40 °C.
Data centre heat recovery is also a way to increase the efficiency of a site. In areas that are densely populated and where demand heat is necessary, the surplus heat might be possible to use in neighbouring buildings or in a district heating system.
The densely populated area also gives a possibility for a closer relationship with the customers using the data centre, which might be a favourable aspect for many data centres.
This is something the industry has grasped in the recent past, especially across the Nordic region where winter temperatures drop well below zero and the heating network has been made available for cooperation.
Big Tech firms like Meta, AWS, Microsoft and Google, as well as leasing real estate players, have been for a while sending excess heat to local heat recovery systems to warm up homes, schools, hospitals and offices.
Recently, STACK Infrastructure and Hafslund Oslo Celsio (Celsio), the district heating provider for Norway’s capital city, have completed a one-year ramp-up and excess heat produced by STACK’s OSL01 data centre is now providing heat and hot water for up to 5,000 Oslo homes.
The idea to feed heat from STACK’s OSL01 data centre near the heart of Oslo into the city’s district heating system was first conceived in 2018.
Over the following years the concept was tested and proven, and a dedicated heat-exchange plant was built on STACK’s campus, where new insulated pipework and cooling coils were retrofitted to the data centre.
The partnership creates a circular economy for energy and STACK’s OSL01 data centre now exports around 3.5MW of heat energy into the Oslo district heating system, reducing Celsio’s alternative energy production by 25,000,000kWh (25GWh).
The use of excess heat in district heating frees green electricity for alternative uses, including for example electrification of the transport sector.
Knut Inderhaug, Managing Director, Hafslund Oslo Celsio, said: “Data centres located in urban areas are stable and good sources of excess heat for district heating, and together we can contribute to the reuse of emission-free heat.
“Projects like this are positive for us as energy providers, for our city and its inhabitants, and for the climate.”
Also commenting, Halvor Bjerke, CEO, STACK EMEA – Nordics, said: “Heat reuse is now standard in our new data centre designs, and we expect to continue collaborating with city authorities as well as heat and power companies to ensure that this circular economy for energy becomes widespread so that the digital economy is a sustainable one.”
In neighbouring Sweden, Conapto, together with real estate company Fastpartner, have signed an agreement for the development of a 10,000 sqm data centre property in southern Stockholm which will also send excess heat to the local heating system.
“We are constantly looking for new opportunities to improve the energy efficiency of Stockholm. In this search, heat recovery is one of the most powerful tools,” said Peter Sivengård, Head of Open District Heating and Stockholm Data Parks at Stockholm Exergi.
“Increased digitisation gives the city’s residents new opportunities while the heat from the data centres is taken care of and contributes to a more sustainable energy system. You can say that the electricity is used twice – first in the servers, then for heating. We will need more such examples in the future so that the energy will be enough when more and more parts of society are electrified.”
Over in Ireland, an AWS data centre in Tallaght, south Dublin, is set to begin delivering heat to a college campus and local authority offices through the district’s heating network.
Donna Gartland, CEO of Codema, the energy agency behind the Tallaght District Heating Scheme, has recently told NewsTalk that the scheme will first cover the TU Dublin campus and the South Dublin County Council offices. New apartments and an innovation centre are due to be connected at a later date.
She said: “This really is a new enough concept for Ireland, but used very widely across Europe. We are actually one of the only countries in Europe that has very low shares of district heating.
“We are less than 1% of our heat demand – whereas the average across Europe is at 12%. And in countries in Scandinavia, they have 60/70% of their buildings connected to these schemes.”
According to Codema, recycling waste heat from Dublin data centres and other by-products of electricity usage could account for 3,579 MW of heat per annum and heat up to 1.6 million homes.
There are many other examples of data centres being utilised to help reduce heating and energy needs in Europe, including Equinix’s (NASDAQ: EQIX) latest partnership which will see the company’s Paris infrastructure be used to warm up the pools in the Aquatic Centre during the Olympic Games of 2024 in the French capital.
CELSIUS wrote in its market report around data centre heat recovery that there is a desire to optimise the availability, efficiency and capacity of a data centre.
“All these three components must work together for the end result to be as optimal as possible,” it said. “By doing so, both energy and money can be saved.”
At a time of great energy uncertainty across Europe, data centres are taking to centre stage, just like they did during the Covid-19 pandemic.