The Swiss capital, Bern, boasts a new world first in the field of renewable energy - the façade of an entire housing block has been converted into a solar energy plant.
The south side of the block, which is 23 storeys high and contains 94 flats, is covered by hundreds of shiny blue panels, rising some 70 metres. It is the biggest facade of any building anywhere to be converted into a solar energy plant.
Catching the sunlight, the panels feed electricity directly into the city of Bern's power grid, producing about 47,000 kilowatt hours a year or sufficient for the needs of 25 households.
The project, conceived and built by Atlantis Energy Systems, has been years in the planning. The main difficulties have been administrative and financial, says director Mario Posnansky.
"The electricity which is produced right now is about five times more expensive than conventionally mass-produced electricity so the question is how do you get this technology into mass production so you can lower the price.
"At the moment, a few people are paying a very high price for this electricity but, of course, if everyone was prepared to pay just a little bit more, then we could make a breakthrough. This is a political issue."
All the apartment owners in the block had to agree to the 40-year use of the facade and they had a number of concerns.
"It was a long process to convince people to agree," says resident Beat Blaser. "People had fears about the construction, about what happens if there is a fire, about electro-smog."
Unlike solar roofs, which supply 75 per cent of total energy production in summer and only 25 per cent in winter, the new solar facade produces equal amounts of energy throughout the year.
The pilot project, which has been supported financially by the federal, cantonal and city authorities, has cost SFr1.4 million ($870,000). Even so, Atlantis has had cash problems, and some of its employees who worked on the project say they have yet to be paid.
"Some of us haven't had our salaries since September, says employee Paul Schmidt. "We produced these panels during the months of October and November without pay."
Some disgruntled employees appeared at the inaugural ceremony this week, and unfurled a banner, which read: "Here's the facade but where are our salaries?"
The management admits there is a cash flow problem and says it hopes to resolve it shortly.
Meanwhile, Atlantis is embarking on other projects which Posnansky hopes will make the facades of buildings "both functional and beautiful".
by Vincent Landon