303,000 natural gas customers in nine counties around the city of Rochester. CMP is the largest energy supplier in Maine, serving over 600,000 customers. Iberdrola USA promotes important infrastructure projects in both Maine and New York. In Maine, CMP began construction in September 2010 of the Maine Power Reliability Program (MPRP), a $1.4 billion upgrade of the state's transmission network which will also improve grid connections to Canada. It also began the roll-out of a smart meter installation plan for 625,000 customers in Maine. In New York, important infrastructure projects have been undertaken at Ithaca and Corning Valley. In 2015 Iberdrola USA merged with UIL Holdings (parent of Connecticut's United Illuminating and other companies) to become Iberdrola-controlled Avangrid. Iberdrola Ingeniería With projects in more than 30 countries throughout Europe, Asia, Africa and North and South America, Iberdrola Ingeniería and Construcción's services include engineering, supply, construction and commissioning, turnkey projects and operational support. In the area of R&D, is developing the Iter project. Iberdrola Inmobiliaria Iberdrola Inmobiliaria offers a range a real estate products, with a focus on residential property, holiday homes, offices, factory premises and shopping centres. Assets in Spain Iberdrola also owns hydroelectric plants, especially in the Duero river basin (provided by Iberduero) and the Tajo and Segura river basins, etc. (provided by Hidroeléctrica Española). Construction is finished on the 848 MW La Muela plant (at Cortes de Pallás, Valencia) and on the 175 MW San Esteban II plan, on the Sil river. The San Pedro II project has started its construction. See also: Saltos del Duero. Combined cycle plants C. T. de Castejón 2, in Castejón (Navarre), with 386 MW. C. T. de Castellón, in Castellón, with two units with a combined 1,650 MW. C. T. de Santurce, in Santurce (Vizcaya), with 402 MW. C. T. Tarragona Power, in Tarragona, with 424 MW. C. T. de Arcos de la Frontera, in Arcos de la Frontera (Cádiz), with two groups with a combined 1,613 MW. C. T. Bahía de Bizkaia, in Ciérvana (Vizcaya), which is operated jointly with three other operators (EVE, Repsol YPF and BP with 25% each), of 780 MW. C. T. de Aceca, in Villaseca de la Sagra (Toledo), of 391 MW. C. T. de Escombreras, in Cartagena (Murcia), with 831 MW. Nuclear plants Iberdrola operates the following five nuclear plants individually or jointly with other companies: Almaraz Nuclear Power Plant (1983/1984) Trillo Nuclear Power Plant