Some buildings, naturally, have rooftops which lend themselves to the cultivation of crops – data centres being one. The mass of space atop these huge warehouses, and the heat that rises from inside, creates a great environment for a modern-age allotment with an extended growing season.

Reid Brewin Architects (RBA) is no stranger to fulfilling such a brief, having recently designed a ground-breaking solution for Paris’ Equinix PA10 data centre, which uses waste energy to power a rooftop ‘urban farm’ – the first solution of its kind in France. Here, Yvonne McCormack, BIM Lead and Architectural Designer at RBA, takes a closer look at the rationale – and opportunities – within modern urban architecture.

Cloud computing is becoming increasingly popular in delivering services to individuals and organisations worldwide. It involves using digital networks to store data in offsite, physical locations – instead of the ‘old way’ of digitally filing information on local computers or storage devices.

While this technology has many advantages that make it attractive, it also brings some potentially negative impacts on the environment, as the ‘data centres’ that house all this information are renowned for high energy consumption levels – as well as the associated emissions from electricity production and cooling systems.

It isn’t all doom and gloom, as savvy developers are increasingly looking for ways to mitigate such effects by utilising clever urban planning solutions that reuse excess heat and ‘give back’ to neighbouring communities.

Cloud computing’s impact on the environment

According to IEA (2022), Data Centres and Data Transmission Networks, data centres consume approximately 1 to 1.5% of all global electricity annually, translating into an estimated 200TW hours annually. This figure is expected to increase significantly over time, due to increased usage rates in data-driven activities – such as streaming media content online.

In addition, the power needs for these facilities generate significant amounts of CO2. In fact, a single large facility can emit up to 100,000 metric tonnes in CO2-equivalent gases – such as nitrous oxide (N₂O) – per year, according to scientific reports.

As such, data centre operators have begun introducing advanced cooling technologies designed to recycle thermal ‘waste’ within their infrastructure rather than relying solely on traditional air conditioning systems for temperature control. Redirecting this unused resource back into operational components within the facility itself could save considerable money (as well reducing overall carbon output) since less power would need to be consumed to maintain comfortable working temperatures inside server rooms.

But there’s more opportunity out there – literally.

Urban planning to reuse excess heat from data centres

Capturing the ‘waste’ heat from these extensive sites can address many of the modern challenges cities face – thanks to the potential for energy redistribution. By utilising the excess thermal energy that would otherwise be ‘lost’ after cooling, it has the power to be turned into a useable resource, which, in turn, creates numerous benefits for urban populations.

Harnessing ‘waste’ from data centres offers the potential for increased quality of life among communities worldwide. And, while the nature of the work inside a data centre means access must be strictly controlled, it does allow operators to give something back to local communities – often a key bargaining chip when applying for permission to build.

For example, communities could gain greater access to green spaces, locally-grown food and recreation opportunities that would otherwise be unavailable due to financial limitations or lack of infrastructure capacity.

Rooftop gardens and urban agriculture offer an excellent opportunity for cities looking to utilise data centres’ excess heat sustainably while at the same time benefiting city dwellers. Providing additional green spaces offers multiple health benefits, too, including access to fresh, locally-grown produce – particularly when space is limited.

Reusing waste heat, water and square feet from data centres for community initiatives, such as urban greenhouses and rooftop gardens, can become an attractive renewable energy source while also providing access to resources with minimal operating costs, improving local air quality and reducing the site’s carbon footprint.

How and why you should get started

The primary advantages are the potential for low-cost energy transfer efficiency and operators’ ability to provide natural air filtration capabilities. However, a few technical challenges are associated with this, such as ensuring safe usage, due to potential risks associated with high-pressure steam or hot liquid systems.

Additionally, it’s important to note that financial costs are involved in adapting existing infrastructure for these purposes. To overcome these obstacles, appropriate regulations must be implemented – along with investment into research – to develop more efficient methods of transferring energy from the data centres.

Warming homes or businesses with the excess heat generated by data centres has the potential to significantly reduce electricity bills compared to other traditional sources, such as coal-burning plants, which emit noxious fumes into the atmosphere, negatively impacting the local environment and overall health quality across the globe.

Unfortunately, there are still some challenges associated with implementing successful waste heat and water reuse projects at scale. These include technical difficulties, such as meeting safety standards set forth by governing agencies, costly overruns incurred during installation, inadequate public education about efficient resource technologies and limited awareness regarding these types of initiatives amongst key stakeholders, including investors.

Despite these obstacles, however, numerous advantages are offered when utilising this valuable source in environmentally-conscious ways while making recreational activities more widely accessible.

Using resources that already exist within our digital infrastructure presents exciting possibilities beyond powering businesses' operations – helping us create healthier communities through increased accessibility at lower costs whilst reducing strain on our planet’s ecosystems.

With proper research into emerging technologies, coupled with innovative approaches towards utilising new forms of renewable energy, we have the potential to enter a new era where even seemingly impossible dreams become a reality, thanks to advances in science and engineering. For those working on the development or management of data centres, careful consideration of reusing the site’s excess thermal output should be explored, and urban planners should consider all factors – including economic feasibility and environmental impact safety concerns – to ensure successful execution sustainability over time.

At Reid Brewin Architects, we are exploring innovative ways to help data centre clients become more sustainable. By providing architectural design services for urban greenhouses and rooftop gardens – which incorporate the reuse of waste heat water and space – and looking at the bigger picture, we hope to bring a holistic approach to data centre design.