The History of District Energy Systems

District energy systems date back to the Roman Empire when heating systems were developed for hypocausts (ancient heating systems), greenhouses, water pipes, and hot water heating. This technology was used even more widely during the fourteenth and fifteenth centuries during a particularly cold period.

Early District Energy Systems

Some of the more noteworthy developments in district energy occurred between 1600 and1850:

• In 1623 there was an (un-built) plan to install district energy in London.
• A Russian palace built in 1783 had an extensive hot water system based on French technology.
• Separate boiler plants and underground piping were used by English factories beginning in the 1790s and by 1820 were commonplace. Waste heat from factories was used to warm public baths by the 1830s and several proposals were put forward to heat worker’s houses with this same heat supply.
• The London’s Crystal Palace had district energy in the International Exposition of 1851.

District energy systems began advancing in the U.S. and Europe in the second half of the nineteenth century:

• At least two steam district energy systems were built in the United States in 1853, the first at the U.S. Naval Academy at Annapolis.
• Factories and institutions began to centralize their steam boilers on a large scale in the 1870s and many new boiler plants were built.
• In 1876, hot water district energy was used to heat several large buildings at an asylum outside London.
• Systems were proposed for Zürich and Warsaw in 1872 and several patents were obtained for district energy in the 1860s and early 1870s.
• The first commercially successful district energy scheme was started in New York in 1877

Modern District Energy Systems

Then in the early twentieth century there was widespread expansion of district energy systems, including:

• The flagship New York project was sold throughout the world over the next eighty years. It is now common in Northern Europe, Scandinavia, the former Soviet Union, and Germany.
• In Northern Europe there are many examples where city-wide district energy schemes have been developed and joined to make bigger networks covering very large areas.
• There are many other smaller schemes in existence serving blocks of flats and groups of buildings.

The World’s Largest District Energy Systems

The figure nearby highlights the location and capacity of the world’s largest district energy systems.