A survey of low-carbon cities worldwide identifies district energy systems as an essential tool for local governments seeking to reduce greenhouse gases and improve energy efficiency.
The U.N. Environment Program report, "District Energy in Cities – Unlocking the Potential of Energy Efficiency and Renewable Energy," calls for the accelerated deployment of district energy systems around the world. From the report's executive summary:
"The development of modern (i.e., energy-efficient and climate-resilient) and affordable district energy systems in cities is one of the least-cost and most-efficient solutions for reducing greenhouse gas emissions and primary energy demand. A transition to such systems, combined with energy efficiency measures, could contribute as much as 58 per cent of the carbon dioxide (CO2) emission reductions required in the energy sector by 2050 to keep global temperature rise to within 2-3 degrees Celsius."
Paris, one of the 45 "champion" cities surveyed, developed Europe's first cooling network, part of which uses the Seine River. The Paris Urban Heating Co., which now serves the equivalent of 500,000 households, aims to use 60 percent renewable or recovered energy by 2020. Other cities in the report include Tokyo, Munich, Hong Kong, Guelph (Canada), Warsaw (Poland) and Christchurch (New Zealand).