There is no doubt about it: Paris is this year's environmental capital. While the city prepares to host the United Nations climate negotiations, one of the great symbols of the metropolis and of France as a whole, the Eiffel Tower, has been given a sustainable makeover after 126 years of a "lofty" career, thanks to the installation of two vertical wind turbines that generate renewable energy.

The tower was built for the Universal Exposition held in Paris from 6 May to 31 October 1889, to mark the centenary of the French Revolution. Its original intended location was Barcelona, which ultimately decided against it. Engineer Gustave Eiffel was therefore forced to move the project to the French capital, where it was erected in the space of two years. The iron structure stands 324 metres tall and was supposed to remain only temporarily before being dismantled, yet went on to become the monument that represents France to the world.

The Eiffel Tower's new profile was created in February by the American company Urban Green Energy (Uge), in collaboration with the Société d'exploitation de la Tour Eiffel (Sete). Following careful study, the two turbines were positioned at approximately 120 metres above the ground in order to better capture the winds that sweep through Paris, and are capable of generating up to 10,000 kilowatt-hours of electricity per year, consumed by the commercial activities on the tower's first floor.

The turbines are silent and painted the same colour as the iron of which the tower is made, so as not to alter the structure's profile in the eyes of visitors, the two companies specified. "The Eiffel Tower is probably the best-retrofitted architectural icon in the world, and we are proud that our advanced technologies have been chosen for a more sustainable future," said Nick Blitterswyk, chief executive of Uge.

The decision to install the wind turbines is merely the latest in a series of sustainable measures. In the past, the tower had been fitted with LED lighting and a ten-square-metre solar thermal panel that heats approximately half of the water (partly collected from rainfall) used by the two floors housing shops and restaurants.