In certain circumstances this is possible, but it must be recorded on the voluntary certificate as an “earmark”. This is because some purchasers of certificates do not want to buy supported certificates. In other circumstances this is not possible: either certificates are not awarded to supported plant, or else they are immediately cancelled.

Voluntary certificates and Guarantees of Origin are given a value by the market, which benefits all parties in the supply chain. Within national support schemes that use them (for instance, Certificati Verdi in Italy, ROCs and LECs in the UK and Elcerts in Sweden), certificates have a value which has been conferred on them by government. To date, these have been managed in systems which are not integrated with EECS. However, EECS will support such certificates should this be required by government.