The Italian government could shortly institute changes to the incentive system for wind energy and other renewable energy sources but any modifications are not expected to affect wind energy. "The idea is to also encourage the development of other renewable sources; not to penalise wind," says Gianni Silvestrini, an advisor to Italian economic development minister Perluigi Bersani. An attractive incentive system is one of the major reasons behind the strong growth of the Italian wind industry in recent years. Operators of wind and other renewable energy plants are issued green certificates, currently for a period of 12 years, that they can sell to producers and importers of electricity required to source a small portion of their retail sales to renewables. The price they receive for the certificates is in addition to the price received for electricity and have proved attractive to investors. The price received for green certificates is the same no matter what type of renewable energy is involved. An expected change is a differentiation between energy sources. Market participants are generally confident that the future incentive system will remain positive for wind, even though already this year Italy will exceed its target for 2500 MW in installed wind capacity by 2010-2012. The government has not yet updated its targets for wind energy to account for faster growth.