Green Certificates (GC, Italian acronym CV) represent a form of support to electricity generation from renewable energy sources (RES). Under Law 244/07, the electricity generated by RES plants commissioned or repowered from 1 April 1999 to 31 December 2007 is certified as renewable electricity (RES-E) and eligible for Green Certificates for the first 12 years of operation of the same plants. The electricity generated by RES plants commissioned or repowered after 1 January 2008 is certified as RES-E for the first 15 years of operation of the same plants. 
Green Certificates are issued by Gestore dei Servizi Energetici S.p.A - GSE on the basis of producers’ reports of RES-E generation in the previous year, or of the expected RES-E generating capability in the current or following year. One Green Certificate is worth 1 MWh of electricity.
For plants commissioned after 31 December 2007 and having a yearly average nominal capacity of more than 1 MW (0.2 MW for wind power plants), GSE issues Green Certificates for 15 years, by multiplying the net electricity (EI) determined for the project by the constants (differentiated by source) shown in Table 2 of the 2008 Budget Law.
Table 2 of the Budget Law was updated by Law no. 99 of 23 July 2009, as shown below:

As a result of the enactment of the Decree of 18 December 2008, GSE makes adjustments for eligible RES (“IAFR”) plants, i.e. it issues additional Green Certificates by applying the multiplicative factors reported in the above table.
Moreover, art. 11 of Legislative Decree 79/99 stipulates that, beginning in 2002, producers and importers of electricity from non-renewable sources are required to yearly inject into the power system a given quota of RES-E. This quota is equal to 2% of the electricity from non-renewable sources generated or imported in the previous year and exceeding 100 GWh/year.
Producers and importers may also fulfil their renewable quota obligation by purchasing Green Certificates that have been issued in respect of RES-E generated by other parties. 
From 2004 to 2006, the minimum quota of RES-E to be injected into the power grid in the following year was increased by 0.35% per year. In the 2007-2012 period, this quota is increased by 0.75% per year. 
Gestore dei Mercati Energetici S.p.A (GME) organises and manages the Green Certificates Market. The following entities may participate in the Green Certificates Market as buyers or sellers: GSE, domestic and foreign producers, electricity importers, wholesale customers, as well as associations (consumers’ and users’ groups, environmental associations, trade unions). To participate in the market, applicants must submit an appropriate application to GME and obtain the status of Market Participants. 
The Green Certificates Market organised by GME provides: 
- liquidity: as per art. 9 of the Ministerial Decree of 24 Oct. 2005, GSE will offer its own Green Certificates in the market regulated by GME itself; 
- transparency: the prices that are set in the market are of public domain; 
- security: GME operates in the market as a CENTRAL COUNTERPARTY and guarantees the payment of transactions. 
Usually, market sessions are held weekly on a continuous trading basis. The dates of the sessions are posted in the “How to operate” section.