What went wrong at the Solar Village?

Savvas Diamantaras has lived in the Solar Village in Pefki, northern Athens, for 18 years and his two-story detached house is heated by a system in which the solar energy is trapped in a greenhouse and stored in walls of water on all south-facing ground-floor walls and about half the surface of south-facing walls on the first floor. «I am quite satisfied. There is hot water from the solar collectors but every now and then I have to add an anti-freeze liquid. Of course, temperatures in these homes are never high. On a sunny day, it is 17 Celsius (63 Fehrenheit) inside. However, we have learned to live with these temperatures. When it is zero degrees Celsius outside, inside it is 13C (55F),» he explained. Diamantaras is just one of the inhabitants of the Solar Village, designed and built built for 435 families eligible through the Worker Housing Organization (OEK) 18 years ago as a model experimental village under a joint Greek-German initiative concluded between what was then the Research and Technology Ministry and its German counterpart BMFT – OEK had made available a 9-hectare property and the capital which it would have used to construct a conventional settlement. When the program ended in 1991, ministry funding was halted and responsibility for the running of the village passed to OEK. The greenhouse system in Diamantaras’s house is still working, but some of the alternative systems installed in other homes in the village no longer function due to poor maintenance. Some residents even claim that the system never worked well from the outset, and that their homes were always cold, forcing them to use electric room heaters. Moreover, no one guaranteed that these systems would be adequate, because the Solar Village is not an ordinary settlement but a housing complex built for experimental purposes. As such, it included a large variety of energy systems – six categories in a total of 54 combinations and variations. Today, most of its residents describe it as being «abandoned by the state.» The system in Eva Yiannopoulou’s house is based on what are known as Trombe walls (sun-facing walls built from material that can act as a thermal mass) which have never proved as efficient as expected. According to their specifications, 60 percent or more of the solar energy that passes through the glass surface is absorbed by a wall of water, heating it for several hours and raising its temperature. Then as the air temperature inside drops, the wall radiates the stored heat. In reality, according to Yiannopoulou, «the system has never worked properly since the time we moved in. The house is always cold, that is why we have fan heaters all over the place, even in the bathroom. When we have guests, we never sit in the living room as it is a larger space and needs two fan heaters. Fortunately, there is double glazing on the windows and the shutters in the north-facing rooms are built of solid metal to reduce heat loss.» The Kokkalis family also thinks fan heaters are indispensable, but has found other problems as well. The rain gutters had been installed upside-down and now the roof is leaking. When Nikos Kokkalis approached the OEK bureau in the village, they told him to get a ladder and go up and see what the problem was. «Usually one gets passed from one person to another and is then told to fix the problem oneself,» he said. Recently he discoverd that the solar collectors on the accessible part of the roof had been disconnected, but no one has done anything about it. Nikos Giuzelakis’s home is heated by a heating fuel furnace and tele-heating network, which produces heat and hot water in an area outside the building – the first time such a system was used in Greece over such a large area. Three-quarters of the village’s residences get the hot water for their central heating and household needs from the village’s Energy Center. «The house has central heating but we don’t have heating elements, the hot air comes out of vents,» said Giuzelakis, who is satisfied with the way the system works. For 10 years, he was president of the Residents’ Association and is familiar with the problems. «The architect, Alexandros Tombazis, designed the settlement which is truly perfect, built according to the principles of bioclimatic architecture. However, the energy systems are outdated and have never been maintained in all the time we have been living here. There are many different variations of the system, so maintaining each of them calls for different kinds of expertise. So residents improvise themselves to try and get them to work.» According to Vangelis Yiannopoulos, a resident who is also a municipal councilor for Pevki, the 252 homes consume 172,000 euros’ worth of electricity and 50,000 euros in heating fuel. «So solar energy accounts for very little of the heating. If the system had been maintained, we could have been the ambassadors for renewable energy sources, but we don’t even have ownership papers for our homes,» he said. Father Panayiotis Pissakis and his family have a different tale to tell. Their heating system consists of glazing and mirrors; all they have to do is raise or lower the shutters. «We don’t pay any heating bills and our home is not cold – the temperature has never fallen below 22C. When it is colder, we turn the space heater on for a while and we’re fine,» he said. The problem in their house is water leaking in from the roof, a common problem among the other residents as well. «The whole roof has to be taken down if the problem is to be solved,» he said. «Why should I pay for the house, when it doesn’t even have a proper roof?» This article appeared in the December 2007 issue of Kathimerini supplement Eco.