We are engaged in two principal lines of business: electricity transmission, where we own and operate Portugal's national high-voltage electricity transmission network (the "RNT"), the only electricity transmission network in mainland Portugal, and natural gas, where we are engaged in the reception, storage and regasification of liquefied natural gas ("LNG"), the operation of the national high-pressure gas transmission network, which we own and operate under respective concessions and the underground storage of natural gas.
Our electricity transmission business is conducted through our subsidiary REN - Rede Eléctrica, which holds a 50 year concession to operate the electricity transmission network in Portugal. This concession was originally granted in September 2000 and renewed for a 50 year period commencing in June 2007, pursuant to the relevant concession agreement between the Portuguese State and REN, executed on June 15, 2007, according to the principles and rules set forth in Decree Law 29/2006 and Decree Law 172/2006. Pursuant to this concession we provide a public utility service in Portugal, which includes planning, constructing, operating and maintaining the electricity transmission network and managing the technical aspects of the national electricity system.
Our natural gas business comprises the ownership and operation of (i) the high-pressure natural gas transmission network in Portugal, (ii) the LNG terminal in Sines, which is engaged in the reception, storage and regasification of LNG, and (iii) our underground storage and related facilities in Carriço. We operate these businesses through 40 year concessions granted by the Portuguese State in September 2006.
Meanwhile, the Portuguese State has granted, as provided for under no. 3 of article 5 of Decree-Law no. 5/2008, January 8, and Decree-Law no. 238/2008, December 15, the concession for the operation of a pilot area for the generation of electricity from wave energy, to Enondas - Energia das Ondas, S.A., company which share capital is 100% owned by REN. According to Decree-Law no. 238/2008, December 15, this concession has the duration of 45 years, and includes the authorization for the deployment of infrastructures for public electricity grid connection and use of hydro resources in the public domain, supervision of the use by third parties of hydro resources necessary for the generation of electricity from wave energy, as well as competence for granting establishment and operation licenses for the generation of electricity and correspondent supervision.
We also operate certain other businesses that complement our core electricity and natural gas businesses: a telecommunications business to exploit the excess telecommunications capacity of our electricity and natural gas networks, an energy trading business, and the Portuguese marketplace for trading Iberian electricity derivatives.