Hot springs and green frogs in Budapest

The water in Budapest not only flows in the Danube, but also collects in vast underground thermal water caverns.

The largest hot spring is around nine meters deep, is located below the city centre in a cupola-shaped cavern around 20 meters in height, and has a temperature of 27 degrees Celsius. More than 30,000 cubic meters of water a day bubble up from over 100 hot springs in the Hungarian capital.

Hot springs are also a feature of Csepel, an island on the Danube whose northern part belongs to the capital. The island is home to the country's largest free port and Hungary's first power station built with private capital. With its modern Csepel II gas-fired combined-cycle power station, Alpiq covers around six percent of Hungary's energy needs and supplies some 20,000 households in southern Budapest with remote heating.

Every day, around 600,000 cubic meters of water from the Danube cool down the steam emitted by the giant turbines. Before the water flows back into the river it is carefully cleaned, filtered and neutralised. Alpiq not only takes great care to ensure the quality of the cooling water, but also informs the residents of Csepel about the air quality, via a monitor installed on the district's main square. Alpiq's Hungarian subsidiary draws up a detailed annual report on environmental protection and sustainability - and is rightly proud of it. In 2007 it was awarded the prestigious Green Frog Award for its report.