Nation Building in the Desert: Cooling Down Dubai

A few years ago, I had the chance to hop on a summer flight out of Toronto for a vacation in the United Arab Emirates (UAE). Headed east from Pearson Airport, our flight soared over the shore of Lake Ontario on its way toward Dubai. For anyone familiar with the two cities —one of which is in an arid desert, and one that is not—you probably know the peak of summer feels a lot warmer in the UAE compared to the Greater Toronto Area; about 15 °C more. And although you can find some great late-night shawarma in both, the intense weather makes dealing with the heat a very different experience in each city.

Yet, despite the significant variations in climate, a powerful energy strategy connects these two urban giants. Hidden deep beneath the streets of both downtown cores lies a shared commitment to an elegant and innovative solution for staying cool: district cooling.

A Nation Rising From the Sands

Once occupied by maritime sheikhdoms, Dubai and the UAE were defined by the rhythms of pearl diving season and the cycle of regional sea trade until the discovery of oil in the mid-20th century (and a looming power vacuum) gave the ruling Emirati families enough motivation and capital to unify their peoples, form a nation, and begin one of history’s most rapid and transformative modernizations.

Dubai’s World Trade Centre Building, along Sheikh Zayed Road, in 1979 (top) and 2020 (bottom) (WAM/AFP)

Nowhere is this transformation more vivid than in Dubai. Driven by a strategy of diversifying away from oil, the Emirate’s leadership reinvested its wealth into creating a global crossroads for finance, logistics, and tourism. Today, that strategy has culminated in a booming, diversified economy where oil contributes less than 1% of it’s GDP. In its place, a dynamic mix of trade, finance, and hospitality now powers the city’s growth. But bringing the modern worlds of business and entertainment to a desert metropolis requires significant amounts of energy and infrastructure. With an economy designed to attract global business and tourism year-round, the fundamental challenges of desert life must be continuously overcome through immense technological and resource-intensive efforts.

Energy-Rich, Emission-Poor

Typical seawater desalination process (Sydney Desalination Plant)

Dubai and the UAE import over 85% of their food and are one of the world’s largest producers of desalinated water. However, the most significant energy challenge is presented by the need for air-conditioning and refrigeration in the Middle East heat, with cooling accounting for over 50% of building energy use (and up to 80% by some estimates). a regional population set to grow by 2M by 2040, a continuously diversifying economy and an ever-warming world, it is clear Dubai’s cooling energy demand is only set to rise.

Thankfully, reinvestment of fossil fuel revenues and a pro-construction landscape have allowed the regional utility DEWA (Dubai Energy and Water Authority) to ensure that electrical capacity has outpaced peak demand over the last decade, nearly doubling overall supply since 2013. Unfortunately, most of this capacity has been in conventional oil and gas power plants, contributing to the relatively high carbon intensity of the country’s electricity grid—making cooling a major source of building emissions in Dubai. Additionally, despite supply currently exceeding demand, each MWh of power dedicated to keeping spaces cool instead of being re-invested to grow the economy, is a dollar wasted. If Dubai aims to achieve any significant goals from the UAE 2050 Energy Strategy, including decarbonizing the power sector by 2050 or significantly reducing capital and operating costs, it’s clear a unique approach had to be taken towards tackling the largest energy obstacle in their way.

Scale-Up to Cool Down

Conventionally, an urban hub like Dubai would be cooled either room-by-room with inefficient wall- and window-mounted A/C units, or from an in-building cooling plant, containing chillers and water-wasting cooling towers. However, when there is an opportunity to service multiple buildings with thermal energy from a large, centralized energy plant (via pipes of chilled water), an economy-of-scale is leveraged in a strategy called district cooling (discussed more generally here!).

The single district cooling plant can serve all the customers via the chilled water piping network (blue) (Hisaka)

The concept offers a variety of benefits but, most importantly for Dubai, the amalgamation of multiple small loads into a single, large and connected thermal demand allows the system to run much more efficiently. On a related note, the improved performance realized by centralization also means less overall plant capacity is required to meet the same demand, resulting in less equipment, and lower upfront capital costs. However, since district cooling is a strategy rather than a technology, its application can take many forms, as exemplified by the completely different systems at both the start and end points of my summer flight that year.

A Tale of Two Cities

As I was flying over Lake Ontario that day, I didn’t realize I had flown directly above the intake pipes to the Deep Lake Water Cooling (DLWC) system, operated by private energy developer Enwave. A system built in coordination with Toronto Water, Enwave’s novel approach allows water from the bottom of Lake Ontario to be treated for drinking, before being used as the main source of heat rejection for their closed loop downtown cooling system on-shore, simultaneously heating the treated and potable water to the appropriate levels mandated by the City. On the city side, the cooled water is then circulated to supplementary chilling plants before collecting waste heat from connected customers and repeating the cycle at the water treatment plant. Currently, the system services over 200 buildings in Downtown Toronto, and displaces hundreds of in-building chillers and cooling towers, dropping power demands for cooling by ~80% and saving 800M+ litres of water annually.

Simplified overview of the DLWC (The Washington Post)

On paper, this sort of system sounds like the perfect solution for Dubai. However, the concept falls apart when the natural water source is saline rather than fresh, as desalination adds extensive time, costs, and thermal inefficiency.

That said, what Dubai lacks in natural cooling resources, it makes up for in innovation and scale. Empower (a subsidiary of DEWA) is the world’s largest district cooling provider, implementing solutions that leverage both TES (thermal energy storage) and TSE (treated sewage effluent) to serve over 1,500 buildings across 80+ thermal energy networks they operate in the region. TES tanks store chilled water produced during off-peak hours, reducing grid strain during peak demand. Because systems in Dubai can’t avoid the use of cooling towers, Empower has integrated TSE as the evaporative medium, ensuring valuable potable water does not vanish into thin air.

Their ingenuity has allowed Empower to install over 1.53M tons of refrigeration capacity, including the largest district cooling plant in the world at Dubai’s Business Bay which will reach a final size of 450K+ refrigeration tons (for scale, the DLWC sits below 100K tons, a typical window A/C unit is about 2 tons). These massive economies of scale, combined with innovative approaches and ideas allow Empower to boast a power savings of around 50% on their centralized systems, a significant achievement considering the role it has in everyday Dubai life.

Staying Cool?

So, is district cooling here to stay in the Middle East?

It’s clear that making life comfortable, even luxurious, in the desert requires a lot of investment of time, energy, money or a combination of it all. Although not enabling full-scale decarbonization yet, district energy systems have proven their ability to act as a true thermal energy network and enable real change in the future. Toronto’s DLWC has grown organically since its inception in 2004, and is still evolving quite drastically. Aside from the expansion of the cooling system itself, Enwave is also enabling interconnection between their heating network to allow waste-heat from air-conditioning operations to act as a low-carbon source of heat. Obviously, in Dubai, waste-heat isn’t as valuable, but as additional thermal assets are developed, whether it be thermal storage, or a passive sink of heat, the same networked characteristic of the DLWC can be leveraged by companies like Empower to swap in and out different sources of energy to the network, maximizing efficiency and performance.

And thankfully, we are already seeing the UAE at-large take advantage of this reality. With hundreds, if not thousands, of buildings connected to district cooling systems nationwide, they have now made significant progress since 2020 in moving roughly 25% of their electricity generation to nuclear or solar sources.

Elsewhere in the region, others are following suit. Abu Dhabi has mandated that all district cooling systems use TSE or other “Recycled Waters” to preserve water consumption, while other regional powers, like Saudi Arabia and Qatar have seen positive trends in green development and sustainable tourism promote new district cooling development. As estimated by Acuity, the district cooling industry in the Middle East is primed to outperform global growth, with numerous private and government-run Middle Eastern entities catching up to Empower on total buildings connected.

It is also worth noting that Dubai and the UAE’s ability to execute such large-scale projects at breathtaking speed is inextricably linked to their governance model. A centralized, authoritarian-leaning political system, led by monarchs with long-term visions, enables decisive planning and the deployment of vast resources—often backed by oil revenues—at a scale and pace that would be unimaginable in many democratic nations.

Yet, this very efficiency raises questions of replicability and cost. At the Middle Eastern scale, these district cooling endeavours are not just energy projects; they are nation-building endeavours with price tags in the billions. While the engineering can be novel and commendable, the extremely high capital costs underwritten by state wealth can create legitimate hurdles to replicate their success elsewhere.

The UAE has positioned itself as pioneers in district cooling and championed the Global Cooling Pledge to reduce cooling-based emissions while hosting the world at COP28; yet they continue to remain one of the top fossil fuel producers and allow fossil-fuels to be a major part of the national economy.

Will they lose their cool trying to do it all?

Ultimately, the UAE’s district cooling revolution is another chapter in their story of leveraging human ingenuity in the face of environmental extremes. Despite their unique governance, their success is a compelling case study into how targeted policy, ambitious engineering, and strategic capital can enable a virtuous cycle of economic growth and environmental stewardship, even in the desert. For the rest of the world, the question is not can it be done, but instead do we have the collective will and foresight to adapt to our own unique circumstances just like the Emiratis have? Can we build cities that are not just cool, but also equitable and just?