District heating: Using data centers to heat communities
9 mins read

District heating: Using data centers to heat communities

Heat Works Energy Center in Tallaght
Heat Works Energy Center – Tallaght, Ireland

If you have followed (or watched) me over the past few years Now go to build), you know that I am very interested in the role technology can play in addressing global socio-economic and environmental challenges. On a recent trip to Ireland, I had the opportunity to visit Tallaght, a growing area in south Dublin that has recently undergone significant revitalization efforts. Here, community leaders, the local energy agency and AWS have come together to rethink the way heat and hot water is provided to everything from hospitals and government buildings to a university campus and public housing. The program is called Tallaght District Heating Scheme and is a collaboration between Codema (Dublin's energy agency), South Dublin County Council, AWS and Heat Works, Ireland's first not-for-profit energy supplier to operate the network. This scheme is the first of its kind on the Emerald Isle, but with recent estimates showing that district heating could meet more than 87% of Dublin's heating needs by 2050, it could be the first of many.

District heating itself is not a new idea. Humans have found ways to centrally generate and distribute heat for thousands of years, from the hypocausts of ancient Rome and the ondoles of Korea to the steam plants of New York in the 20th century, which power a significant portion of Lower Manhattan (nearly 1,500 buildings in the city) heating and cooling still get their heat from steam). And although these solutions have been around for a long time, they have not always been sustainable. Many of these heating systems used the burning of coal and other fossil fuels to produce heat, which we now know causes significant emissions and drives climate change. More recently, combined heat and power systems, such as CopenHill in Copenhagen have provided a model to capture the heat generated by critical infrastructure such as waste incineration and use it to heat the community. That brings us back to Tallaght and why their new district heating program is so important to Ireland's energy future.

Today, Ireland is undergoing a significant energy transition away from fossil fuels and has the ambitious goal of reducing its greenhouse gas emissions by 51% by the end of the decade. To get there, local leaders find new solutions to old problems. Amazon, for example, has invested in three Irish wind farms to add clean energy to the country's power grid. And in Greater Dublin there are new opportunities to develop renewable and underused energy sources, including deep geothermal energy and waste heat from industrial and municipal processes (e.g. data centers, waste treatment plants, even breweries). Codema estimates that these untapped sources can produce around 19 TWh, which is enough energy to heat around 1.6 million homes and plays an important role in Ireland's decarbonization efforts.

This is how district heating works

In simple terms, district heating is heat that is generated in a central location (e.g. hot water), then distributed via insulated pipes to the community where the heat is withdrawn from homes and businesses, and in many cases, such as in Tallaght, where the cooled by-product is returned to the system for reheating.

District heating systems are an attractive option for communities looking to reduce their carbon footprint. These systems are energy source independent – ​​they can use electricity and heat from various sources, including renewable energy. This flexibility allows these networks to adapt over time as new technologies emerge and climate goals evolve. For example, you can switch from biofuel to using recycled heat from waste incineration. They also reduce the infrastructure burden on homes by eliminating the need for individual boilers and water heaters. The ability to select and switch energy sources helps future-proof these systems and offers communities and residents flexibility that is not always possible with other heating solutions.

From hot air to warm water to heat

Servers generate heat. And to ensure efficient operation and protection of these servers, data centers are usually cooled with huge ventilation units. However, if we look at the byproduct of server operations as an opportunity, we see how the heat can be used positively. In our data center in Tallaght, hot air from servers is captured by a heat exchanger in the ventilation system, increasing the temperature of the water flowing through the building to around 23-28°C (for my American readers that's 73-82°F) , before being pumped via insulated pipes to the Heat Works Energy Center. The system takes this warm water and passes it through the first of two heat pumps, where it condenses until the temperature is approximately 45°C (113°F). The hot water then passes through a second heat pump, where the water temperature is increased again to 70 to 85 °C (158 to 185 °F), depending on the season. At this point, the hot water leaves the energy center in insulated pipes and is available to customers connected to the heating system.

Abstract view of heat movement through Tallaght's district heating system
This is an abstracted view of the movement of heat through the district heating system

While a typical home uses individual water heaters or boilers in a district heating system, these are replaced by thermal interface units that transfer hot water from the system to a building or home when needed. They also act as pressure breakers, ensuring that backflow does not occur.

As homes and businesses use heat, the water that lost heat in the energy transfer process is returned to the Heat Work energy center. It then goes through a pump to be further cooled to ~15°C (59°F) before traveling to the AWS data center where the heating process begins again.


Monitoring plays a critical role in any large-scale system, be it a data center, a distributed application, or a district heating program. It allows for design with fault tolerance in mind – knowing that things will fail at some point, but also providing the ability to quickly identify problems and maintain operations when components fail. The Tallaght district heating system is monitored 24/7 by Heat Works. You can see water and air temperature, pressure, flow rate and energy production at any heat pump at any time – you can even detect leaks in the system down to a few meters. This last part is a big deal, considering that in the past repair crews have often relied on visual indicators like steam to identify a leak (which is quite difficult in warmer months).

Heat Works' dashboard to monitor the system
This is a view of the dashboard Heat Works uses to monitor the Tallaght district heating system

If you need an example of the importance of monitoring and network modernization projects, look no further than the UK Lose 3 billion liters of water per daybecause the hydrophones designed for metal pipes have a difficult time detecting leaks in the newer plastic pipes in the system.

What's next?

Today, the collaboration between AWS and Heat Works provides Tallaght with 3MW of energy from the local data center that previously came from gas or fossil fuels. That's enough to heat around 43,000 m2 of public buildings, including the local university, library and innovation center, and has reduced CO2 emissions in the region by almost 1,500 tonnes per year (equivalent to the mass of about 7.5 adult blue whales or an average of 730). -big cars). Over the next two years, the plan is to double energy production and expand the program to include residential buildings and other critical infrastructure in the community.

Tallaght's district heating system demonstrates the huge potential for sustainable community energy systems in Ireland. And it's a great example of how government agencies, utilities and industries in the country can work together on large-scale projects that not only work toward decarbonization goals, but can also help revitalize communities and ensure they have reliable access to energy and heat .

And just as important as the district heating program itself is the change that is underway in Tallaght. They have embraced industries like cloud computing, they are investing in their youth with educational programs ranging from elementary school to university, and the local hospital has adopted machine learning and other cloud technologies to improve patient outcomes in their community. Like the many components of the network that provide heat, this model of cross-industry collaboration shows that when everyone contributes, everyone benefits. Give and take, input and output. In a world trying to balance sustainability with connectivity and consumption, Tallaght is a blueprint for how industry and communities can come together to achieve amazing results. I hope this model will be widely used in the coming years.

Now start building!