International. A transition to modern district energy systems could contribute to a 60% reduction in energy sector emissions required by 2050, and reduce primary energy consumption by 50%, according to the new report "District Energy in Cities: Unlocking the Potential for Energy Efficiency and Renewable Energy", launched by UNEP (United Nations Environment Programme).
In particular, the demand for cooling is growing worldwide and spending on energy services is on the rise. According to the IEA (International Energy Agency), energy consumption for the cooling of premises increased 60% globally between 2000 and 2010, and is set to expand to 625% by 2050 in certain regions of Asia and Latin America.
Through an analysis of the 45 "champion cities," the report notes that while the contributions of energy districts are important and growing, the full potential of these systems remains largely untapped.
Several existing cooling plants or projects, reflecting three different technologies (electric coolers, free cooling and absorption chillers expelled by waste heat) of the district stand out:
- In Doha, Qatar, the Refrigeration Plant at La Perla, powered by several chillers, is the largest of its kind, with a capacity of 456 MW. The district cooling network in Paris uses electric chillers to produce much of the cooling. This has led to 90% fewer refrigerant emissions; 65% less water used; 50% less CO2 emissions; 35% less electricity used; and a 50% improvement in primary energy efficiency.
- The Toronto District Cooling System in Canada uses the new municipal water pipe to extract cooling from deep in Lake Ontario with a cooling capacity of 263 MW, reducing electricity consumption for cooling by 90%. Port Louis, Mauritius, is developing a deep seawater cooling system that will take water 1,000 meters below sea level to cool the commercial building by 2016; this could reduce the demand for electricity for cooling by 65 to 80%.
- The new development of the London Olympic Park uses a 4 MW absorption machine at the trigeneration plant – complemented by two 7 MW ammonia coolers – and is designed to produce 64 MW of cooling (up to 18 MW today). The pilot project in Velenje, Slovenia, using waste heat absorption machine technology has achieved significant electricity savings relative to normal cooling technologies, at a production cost that is 70% of that of normal cooling technologies.
