New technology: district cooling: staying cool in the desert

The Arab Gulf states are considered “environmental wastes” because of the enormous electricity consumption to cool their buildings. Because: “Air conditioning accounts for around 70 percent of electricity consumption in Saudi Arabia in summer,” admits Saleh Al Awaji, Vice Minister for Water and Electricity. Temperatures of over 50 degrees in summer require air conditioning in offices, schools, factories, hospitals and homes. There are said to be as many air conditioning systems running in the kingdom as the population is large: 35 million.

According to Al Awaji's assessment, today's consumption for cooling is unlikely to be the peak given the growth of the economy, the construction of new industries, data centers and housing. What is particularly bad is that so far the majority of electricity comes from oil and gas power plants.

But some companies in the Gulf have now become world market leaders when it comes to efficient cooling: the new system is called District Cooling, i.e. cooling entire city districts instead of individual apartments or buildings, i.e. district cooling analogous to district heating.

Building such new systems is expensive, but the savings effect is enormous. The cooling plant alone easily costs 100 million dollars. Added to this are the costs for the required insulated pipe network. The pipes required cost between $500 and $1,500 per meter, depending on the diameter.

There is also an ice tank and tanks for cooling water in which cold water is stored, like a battery, so that it can be passed through the pipe system through entire blocks of houses, factories, airports or forests of skyscrapers such as Doha's high-rise island The Pearl or Dubai's district around the world's tallest building, Burj Khalifa, at 828 meters, including the Dubai Mall.

The systems should be 40 percent cheaper and significantly lower in CO2 emissions over their life cycle than conventional cooling. “District cooling uses, on average, half as much electricity as traditional cooling methods,” says Khalid Al Marzooqi, CEO of Tabreed. He calls the company, based in Masdar City, once planned to be the world's most sustainable city in the emirate of Abu Dhabi, the "world leader in district cooling." Yasser Salah Al Jaidah, CEO of Qatar Cool, emphasizes: “There is no one out there doing what we are doing and from whom we could learn.”

In the world of gigantomania in the Gulf, both companies see great export potential for themselves and possible technological leaps: Tabreed is building a plant in Masdar in which waste heat is pressed into the desert sand using heat pumps. In Saudi Arabia, experiments are being carried out with systems that supply the enormous water requirements for the cooling systems with seawater or treated wastewater. In another experiment, added nanoparticles should be able to absorb and dissipate more heat.

The rivalry in the Gulf could be useful in a human issue that is becoming increasingly important as heat waves continue to grow. According to the International Energy Agency (IEA), a fifth of global electricity consumption is currently used for cooling. By 2050, the UN estimates, it will be half that. Because the demand for cooling will triple. The market for district cooling systems is expected to double by 2034 – to $60 billion annually.