One major benefit of using this system is that it effectively applies the principles of circularity to support and enable multi-energy systems.
As India experiences more frequent and severe heat waves, the use of air conditioning is escalating across the nation, resulting in an increase in power consumption, which in turn is growing emissions and causing harm to the environment. Sustainable cooling solutions are urgently needed to address risks to health, food loss and productivity declines due rising temperatures, while ensuring the country’s efforts towards decarbonization are not impeded.
India's growing population and rapid pace of urbanization is further exacerbating this challenge. India has already surpassed China as the most populous country in the world. Estimates suggest that India will add over 416 million urban residents in its cities between 2018 and 2050, bringing the urban population to over 850 million by the end of the period. The increasing temperatures coupled with rapid urbanization is putting pressure on the country’s infrastructure needs and simultaneously on the environment. Key findings of India Cooling Action Plan indicate that the nationwide cooling demand is projected to grow around 8 times by 2037-38, implying there will be demand for a new air conditioner every 15 seconds, leading to an expected rise of 435% in annual greenhouse gas emissions over the next two decades.
District cooling technologies provide a viable alternative as a climate responsive cooling technique to address these multiple challenges. In a district cooling system (DCS), chilled water is generated in a central plant and then distributed through a network of insulated pipes to multiple buildings in the area, similar to other utilities like water, electricity and gas. DCS not only halves the energy requirement for cooling as compared to traditional systems but also promotes the transition to a circular economy. Due to its ability to aggregate demand and leverage economies of scale, district cooling plants require lower capital outlay and have more optimized energy usage as the system operates at peak loads most of the time, attaining its intended design efficiency. Using innovative business models such as Cooling as A Service (CAAS), district cooling systems can be deployed at scale, aligning incentives for the most efficient operations and maintenance. It is estimated that CAAS can help save up to 25% of cooling costs for customers, while reducing emissions from electricity use and coolant leakage by up to 50%.
A key advantage of adopting DCS is that it operates well on the principles of circularity to support and enable multi-energy systems. To illustrate – since peak demand for cooling often coincides with peaks of solar energy, distributed renewable energy (DRE) systems can be utilized effectively through integration with DCS. By installing a DRE system or a solar captive plant in the vicinity of the district cooling system, the electricity generated by the plant can be used to power the cooling system during the peak hours, reducing the reliance on grid electricity and reducing carbon emissions. Any excess electricity generated can be stored in thermal energy storage tanks, to be used later to take advantage of time-of-day tariffs. Similarly, a district cooling system can utilize natural water sources or treated sewage effluent (TSE) from sewage treatment plants (STPs) to provide centralized cooling to buildings, thereby reducing the strain on supply of potable water. City gas distribution companies and waste to energy plants can become viable by getting anchor demand from DCS, and in turn add system-level redundancy to the district cooling plant, eliminating the need for power back-up in the form of generator sets, which are one of the biggest sources of PM 2.5 and 10 in cities. For waste to energy plants, waste heat can also be converted to cooling using vapour absorption chillers, subsidizing the cost of energy and making it competitive with various renewable sources.
This way, the operating cost of the district cooling plant is significantly reduced, power consumption from the grid minimized through integration with renewable resources as well as alternate sources of energy to build resilience in the system. For ever-expanding and developing urban areas, competing for scarce resources and space, prioritizing systemic solutions that promote higher efficiency, improved circularity of resources and lower future emissions can greatly contribute to successful place-making, long-term sustainability and social equity.
India's initiatives to decarbonize and mitigate climate change will be critical to the world meeting the Sustainable Development Goals. The Indian government's pledge to achieve energy independence by 2047 and a net-zero economy by 2070 demonstrates the country's resolve to play its role. Implementing sustainable and holistic cooling solutions such as district cooling that take the systems view and promote principles of circular economy across vital sectors such as real estate, cold chain and refrigeration, transport and data centers, and government initiatives such as urban planning and smart cities will help India's energy transition efforts in the long run, solidify India’s leading position as a green, inclusive and growing economy.
(The author is Vice President – Business Development, Tabreed, a district cooling provider)