"For wind plants, as for all plants with an intermittent functioning, there is the problem of the compatibility of new connection requests to the electricity network with the current capacity of that network, so as to not compromise the continuity and the security of the territory," said the grid operator.
As it waits for the Sicilian transmission network to be expanded and improved as part of its plans to develop the country's outdated transmission system, GRTN said a maximum 503 MW in wind capacity could be installed on the island. Since 262 MW is already operating there and another 135 MW had been permitted, that left room for only 106 MW more, said GRTN.
After meetings with the wind project developers, however, GRTN acknowledged last month that it had miscalculated the volume of power currently being fed to the Sicilian grid. Developers now say there are no problems with new plant connections for the time being.
GRTN still says the national grid network needs to be reinforced and modernised, particularly in Sicily, one of the few Italian regions to export electricity. "The high tension network is insufficient with respect to consumption," it says. The grid operator has prioritised two Sicilian grid reinforcement projects -- a 380 kV power line across the Strait of Messina between Sicily and Calabria and a 380 kV power line within Sicily, from Ragusa to Palermo, both slated to be completed by 2009.
Although wind power accounted for just 0.6% of national electricity production last year, grid integration problems are also expected outside of Sicily, particularly in southern Italy, says Alessandro Brusa of Italian renewable association Associazione Produttori Energia da Fonti Rinnovabili. "We also expect situations of weakness, although not right away, in Calabria and Apulia," he says.
Brusa hopes for a deeper debate to solve the problems of integrating wind. Development of a widespread wind forecasting system operating beyond the level of single wind stations could help in predicting, and thus managing, peaks and lulls in the wind, he adds, welcoming GRTN's pledge to study the possibility.
There are already technical options for easing assimilation of wind into the Italian power system, points out wind consultant Paolo Montanari of MX Matrix. Just as hydro storage is used to respond to fluctuations in demand, it can also help with the management of wind power by pumping water into reservoirs in times of excess production, for later use as hydro power when there's a generation shortage, he says. "Something else GRTN could do is to impose limitations on the use of the older most polluting thermoelectric plants, interrupting their functioning when the wind is strong."