91During scorching summers, air conditioning becomes an essential tool for people to escape the heat. According to data published by the International Energy Agency, the number of air conditioners in global buildings is expected to grow from 1.6 billion in 2018 to 5.6 billion by 2050. To explore greener and more efficient cooling models, the United Arab Emirates (UAE), Singapore, and Germany are promoting the development of district cooling systems, viewing them as important pathways to achieve green cooling and reduce carbon emissions, better addressing climate change and realizing energy transitions.
UAE — Technological Innovation Boosts District Cooling Development
Recently, the highest temperature in Dubai, UAE, has exceeded 40 degrees Celsius. Walking into the Dubai Mall, a cool and comfortable breeze greets you. Through dedicated pipelines, a constant flow of cold water travels from the cooling station to the buildings, meeting the cooling needs.
Due to the high average temperatures in the UAE, there is a significant demand for cooling, making district cooling the primary cooling method for public facilities such as malls and office buildings. District cooling involves setting up centralized cooling stations in a specific area to produce cooling sources, replacing the decentralized cooling systems built by individual public buildings. Then, low-temperature water is delivered to heat exchangers via distribution networks, and after heat exchange, 7 to 9-degree Celsius low-temperature water is supplied to the terminal fan coil units of each user. Carlos, head of the energy policy department at the Abu Dhabi Department of Energy, introduced that compared to traditional cooling systems, district cooling consumes less electricity and has advantages in saving energy and reducing costs.
In recent years, the UAE has vigorously developed district cooling. According to reports from the Emirates News Agency, cooling buildings accounts for 70% of electricity consumption in the UAE, and district cooling can effectively improve the energy efficiency of cooling and significantly reduce energy consumption. The Dubai government has identified the development of district cooling as a major initiative to reduce water and energy consumption, aiming to meet 40% of cooling needs through district cooling by 2030. UAE district cooling companies have also experienced rapid growth. In 2023, the UAE Central Cooling Systems Company provided district cooling services to over 1,500 buildings in Dubai, with a pipeline network totaling about 400 kilometers; the UAE National Central Cooling Company added 31,000 tons of refrigeration capacity, bringing the total installed capacity to over 1.3 million tons.
Managing cooling equipment using artificial intelligence, improving pump efficiency, and enhancing cooling efficiency... Besides accelerating the construction of infrastructure such as cooling plants, the UAE is also promoting district cooling development through technological optimization and innovation. At the end of 2023, the Gulf region's first district cooling project utilizing geothermal energy officially began operations. Developed in collaboration between Abu Dhabi National Oil Company and the UAE National Central Cooling Company, the project extracts natural hot water from underground wells and uses absorption chillers to produce the low-temperature water needed for district cooling. "Building cooling is one of the largest energy consumers in the Gulf region, and we look forward to exploring more ways to achieve green development with our partners," said Kabi, head of low-carbon solutions and international development at Abu Dhabi National Oil Company.
Rob, President and CEO of the International District Energy Association, stated that district cooling is one of the important pillars for the UAE to improve energy efficiency and reduce carbon emissions, and it is a wise move to address global climate change challenges. Ahmed, CEO of the UAE Central Cooling Systems Company, said, "We will continue to improve the efficiency of district cooling systems and distribution networks to contribute to the protection of resources, environment, and climate in the UAE and globally."
Singapore — Increased Promotion in Commercial and Public Housing Areas
Beneath the Marina Bay Sands mall in Singapore lies a large cooling plant with crisscrossing pipelines operating 24/7. The cooling plant, located more than 20 meters underground and covering an area of about 10,000 square meters, delivers chilled water at approximately 4.5 degrees Celsius daily. This underground cooling plant is part of the Marina Bay district cooling system network. Designed, built, and operated by the Singapore Energy Group, this district cooling system uses large-scale chillers to cool water, which is then transported through pipelines to various connected buildings in the Marina Bay area. Building owners can use the chilled water from the pipelines to regulate indoor temperatures. Heat generated during the cooling process can be used to produce hot water for hotels and restaurants.
To achieve green cooling, Singapore has been actively promoting the construction of district cooling systems in recent years. Taking the Marina Bay district cooling system as an example, it provides cooling for over 20 buildings in the Marina Bay area, helping the region save 40% of its energy consumption. Additionally, the underground district cooling system in Marina Bay has freed up about 16,000 square meters of space by eliminating the need for mechanical rooms. It is reported that the Marina Bay district cooling network will further expand, covering 32 projects by 2027, reducing annual carbon emissions by 25,000 tons, equivalent to removing 22,700 cars from the roads.
Aside from commercial use, the Tengah Town public housing area in Singapore will also attempt to widely adopt district cooling systems. The cooling system will be installed on the rooftops of public housing buildings, delivering chilled water through a closed-loop pipeline to each indoor air conditioner to achieve cooling effects. Each cooling unit can serve 8 to 10 public housing buildings and will be connected to multiple units to form a district cooling system. It is estimated that if all residents use the district cooling system, the energy saved annually could power about 4,500 four-room public housing units. Compared to traditional split-type air conditioning systems, central cooling systems can save an average of 30% in energy, plus annual maintenance costs, allowing residents to save about 20% on expenses.
Hassan, Managing Director of Sustainable Energy Solutions at the Singapore Energy Group, said that cooling can account for up to 60% of a building's electricity usage, and district cooling systems can be a more reasonable solution in terms of cost savings, reliability, and energy efficiency. Additionally, the Singapore government has taken measures such as increasing green spaces to reduce temperatures, launching the "City in Nature and Skies" initiative to encourage developers to incorporate green spaces or rooftop gardens into their designs and offering corresponding subsidies. Under the influence of these measures, the green space on high-rise buildings in Singapore has increased by more than one-fold over the past decade.
Germany — Promoting the Combination of Cooling and Heating Technologies
In recent years, Germany has accelerated the exploration and development of eco-friendly district cooling models. Taking Munich as an example, the city is constructing a large district cooling center, planning to fully utilize natural cold water from groundwater and rivers or use geothermal energy for cooling. This district cooling facility will be connected to the city center via a 6-kilometer-long pipeline. Once completed in 2029, the center is expected to have a cooling capacity of 36 megawatts. Munich City Utilities aims to increase the cooling capacity to at least 130 megawatts by 2030. It is reported that compared to individual air conditioning systems, district cooling can reduce electricity consumption by 50% to 70%.
At the same time, cooling and heating technologies can be combined to improve energy efficiency. In the new electric bus garage in Munich, which began operations in 2022, groundwater from the district cooling facility is used to cool charging stations and server rooms. The waste heat generated in this process is further utilized. On one hand, the waste heat prevents ice formation at the garage entrances and exits during cold seasons; on the other hand, through the return water pipes of the district cooling network, the waste heat can also heat nearby 114 apartments. After the hot water returns and cools down, it goes back to the aquifer, starting a new cycle of utilization.
A report by the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety, and Consumer Protection in Germany pointed out that inefficient building and cooling management will lead to increasing energy consumption and greenhouse gas emissions. Without intervention, greenhouse gas emissions from buildings are expected to triple over the next 30 years. To promote sustainable green cooling, the German government is actively promoting cross-sector cooperation. For example, in Bad Nauheim, Hesse, local utility companies, energy companies, and research institutions such as the University of Erlangen-Nuremberg and Dresden University of Technology are jointly involved in the construction of a district cooling project.
According to the introduction, the municipal engineering company in Bad Nauheim laid geothermal collectors 1.5 meters underground to collect geothermal energy that remains around 10 degrees Celsius throughout the year. The smart center collects data from underground sensors, groundwater monitoring points, and temperature sensors in real-time. Based on data analysis, the heat pump network provides heating or cooling to users as needed. By efficiently collecting and innovatively using geothermal energy, the system provides green cooling to about 400 households and 1,200 residents in the southern area during summer and green heating during winter. Volker Stokinger, a scholar involved in the project, noted that this is a flagship project utilizing shallow geothermal energy for innovative heating and cooling supply, worthy of promotion.
