Pallav Purohit
Visiting Research Fellow, IISD

Increasing temperatures will make space cooling a necessity for maintaining comfort and protecting human health, and rising income levels will allow more people to purchase and run air-conditioners (ACs). At the global level, cooling technologies (i.e., ACs and electric fans) account for nearly 20 percent of the total electricity consumption in the building sector. The demand is expected to grow with rising temperatures due to climate change, and economic and population growth.Increasing demand for space cooling is also putting enormous strain on electricity systems in many countries, as well as driving up air pollution and carbon dioxideemissions. According to the International Energy Agency, the energy demand from ACs would more than triple by 2050 and the stock of ACs would increase from about 0.9 billion in 2017 to over 3.7 billion in 2050, if the current trends continue.

Space cooling demand in India
In India, the cooling demand is growing at the rate of 15-20 percent annually. India'scooling demand is mainly driven by increasing per capita wealth of households, rapid urbanization, population growth, and more frequent and extreme heatwaves. Space cooling for buildings currently dominates the total cooling energy demand in India and buildings are expected to drive major demand for cooling in the country in the future. In 2016, only 4 percent of households in India possess an AC, despite having extremely high cooling needs due to affordability and lacking access to electricity. However, AC ownership and use is rising rapidly in India as incomes rise, access to electricity improves and prosperity becomes more widespread.

Energy demand for space cooling in buildings in India is rising rapidly, placing a burden on the electricity grid and contributing to local air pollution and carbon dioxide emissions.Final energy consumption for space cooling in India is also growing very rapidly, having risen 15-fold between 1990 to 2016.The stock of room ACs has risen steeply from 2 million units in 2006 to approximately 30 million units in 2017 and is expected to increase to over 800 million units in 2050. As a result, the share of space cooling in peak electricity load is projected to rise sharply from just 10 percentin 2016 to 45 percent in 2050.

Alternative low-GWP refrigerants for room Acs
The significant climate impact of room ACs does not only come from a mainly coal-based electricity supply but also results from the widespread and rapidly growing use of halogenated refrigerants such as HCFC-22 (GWP100 = 1,960) and HFC-410A (GWP100 = 2,256), which today have a significant share of the overall greenhouse gas (GHG) emissions caused by room ACs. Many hydrofluorocarbons (HFCs) have a very high GWP (global warming potential) and are subject to global phase-down under the Kigali Amendment to the Montreal Protocol. In advance of Kigali Amendmentobligations, several room-AC manufacturers have turned to HFC-32 (GWP100 = 771) as a lower GWP alternative to HFC-410A. However, the GWP of HFC-32 is still higher than that of a growing number of low-GWP refrigerants introduced commercially in the years following the introduction of HFC-32 in the refrigerant landscape. Over the last few years, more than 90 percent of new room ACs in the Indian market now contain HFC-32.

Propane - the future of room ACs ?
Energy-efficient room ACs using propane (GWP100<1) as a low-GWP alternative to HFC-410A (or HCFC-22) are commercially available in the Indian market and account for about 2 percent of annual sales of room ACs in India. ACs using propane perform similarly to those using HFC-32 and are more efficient than currently widespread appliances using HFC-410A and HCFC-22. Moreover, room ACs based on propane perform better in warm climates. The Life Cycle Climate Performance studies indicate that ACs using propane have the lowest climate impact compared to other low-GWP alternatives of HFC-410A in this sector, primarily due to the lower refrigerant emissionsfollowed by lower energy consumption compared to other low-GWP alternatives. The world could avoid a 0.09^oC rise in global temperatures before the end of the century by switching to using propane as a refrigerant in room ACs, thereby making a significant contribution toward keeping the global temperature rise below 1.5^oC. Although the switch to HFC-32 reduced the global temperature rise (0.03^oC by the end of the century), using propane proved to be the more sustainable solution.

In comparison to HFC-410A-based units, propane-based ACs have higher production costs by about 6 to 10 percent, because they need additional safety measures. However, their operating costs are lower since they are more efficient and use 40 to 60 percent less refrigerant (propane) than HFC-410A. In addition, HFC-32 is flammable, unlike HFC-410A, but propane is more flammable than HFC-32, and its flammability is rated at grade A3. While room AC manufacturers using alternative refrigerants (i.e., propane) will have a marked competitive edge in India however, there exist several barriers to the uptake of room ACs using propane including lack of awareness among consumers, high costs, challenges with retrofitting and concerns around safety and standards.

While there have now been many calls for greater uptake of natural refrigerants in AC systems, the major AC manufacturers are yet to show signs of movinglargely due to safety standards regarding the use of flammable refrigerants.Therefore, the regulators are encouraged to support the adaptation according to technological improvements of these safety standards to allow larger charge sizes while including guidance on safe application. The recent decision by the International Electrotechnical Commission IIEC) to approve an international standard on safety requirements for electric heat pumps, air conditioners and dehumidifiers for domestic use allows for higher charge limits for hydrocarbons such as propane and other flammable refrigerants in domestic technology which in turn means potentially massive reductions in the emission of high-GWP refrigerants. A room AC unit using propane (<7kW) will require less than the higher load of flammable refrigerants allowed by the IEC.

India's Cooling Action Plan
At the global level, India is one of the first countries to develop a comprehensive National Cooling Action Plan (NCAP) which has a long-term vision to address the cooling requirement across sectors and lists actions that can help reduce the cooling demand. ICAP was launched in March 2019 by the Indian Ministry of Environment, Forests and Climate Change. The plan provides a 20-year perspective and outlines actions needed to provide access to sustainable cooling. The NCAP seeks to (i) reduce cooling demand across sectors by 20-25 percent by 2037-38, (ii) reduce refrigerant demand by 25-30 percent by 2037-38, (iii) reduce cooling energy requirements by 25-40 percent by 2037-38, (iv) recognise "cooling and related areas" as a thrust area of research under national science and technology programme, and (v) training and certification of 100,000 servicing sector technicians by 2022-23, synergizing with Skill India Mission. In addition, the Indian Bureau of Energy Efficiency Star Labelling program is already strengthening room AC efficiency standards and labels every year.The GWP limit of the refrigerants in the room AC sector and awareness of the customers about the energy efficiency and labels could further enable a sustainable cooling sector in the country.

In India, the energy consumption for space cooling is set to rise in the future. This will result in increased use of refrigerants andenergy use for cooling, thus increasing direct and indirect GHG and air pollutant emissions. Transitioning to propane in the room AC sector with an enhanced energy efficiency of cooling technologies will enhance the overall climate benefits and improve local air quality. To achieve India's ICAP targets,nationally determined contributions and Kigali pledges it is critically important for a rapidly developing economy like Indiato make available sustainable cooling solutions for its citizens and promote local manufacturing of energy-efficient appliances for refrigeration and air-conditioning. Most importantly synergistic actions with respect to cooling across sectors will have a higher impact than actions taken in isolation.
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Pallav Purohit is Visiting Research Fellow, IISD.