Orly Airport has recently announced that it plans to provide more than a third of its heating needs via geothermal energy. Slated for completion in 2011, the $17 million dollar project will cut annual CO2 emissions by 7,000 tons from the current level of 20,000 tons. As France’s second busiest airport, Orly aims to be its greenest by launching of a vast program intended to increase its energy efficiency by 20% by 2020 and 40% by 2040.Geothermal heating systems have been around since the times of the Roman Empire, when hot water streams were used to heat buildings and spas. Today’s systems generally employ a geothermal heat pump to regulate heating and cooling via the earth’s fairly constant temperature of around 50°F that is just 5-10 feet underground.
Orly’s plan differs insofar as it will take advantage of a large cache of hot water directly underneath the airport, eliminating the need for a heat pump. The geothermal system will drill two 1,700 meter deep shafts at the perimeter of the airport. Water heated by the earth’s core will be drawn upward via natural pressure, reaching the surface with a temperature of 74°C (165°F). From there it will enter the airport’s heating system and then be cycled back into the earth through the second shaft. The system stands to cycle 250 cubic meters of water per hour, providing for 35% of the airport’s heating needs.
Pierre Graff of Aéroports de Paris stated: “We have the unprecedented luck of having a layer of water beneath our feet that can heat a large part of Orly without CO2 emissions. We are the first airport in Europe to do this.” It’s great to see airports taking such strident steps to help offset their immense carbon footprints! Construction will begin in 2009.