The first wind plant on the Iberian peninsular to use megawatt turbine technology at heights in excess of 1000 metres has come on-line in the north of Portugal. The developer of the 11.7 MW Cabeço Alto plant of nine 1.3 MW kW Nordex turbines is Enersis SA. The project is 1400 metres above sea level in the Montalegre area, bordering the Spanish region of Galicia. Average wind speeds are 7.8 m/s and Enersis expects the plant to produce about 27 GWh/year for its overall investment of PTE 2.5 billion (EUR 12.5 million). Norbert Dwenger of Nordex says the main challenge of the turnkey contract with Enersis was posed by changes in circuit cooling behaviour caused by reduced air density at the high altitude. Adjustments were required, mainly to transformers and generators. Enersis was founded in 1988 as an independent small hydro developer and moved into wind in 1995 with the development of its 10 MW Vila Lobos wind plant, which came on-line in March 1998. In October last year its 3.3 MW Mafra plant of two Vestas 1.65 MW turbines started work. Enersis expects to start up a further ten Nordex 1.3 MW turbines by early November in its Lomba da Seixa plant in the same district. This will bring the company's total wind capacity to 41.6 MW out of a national total of 80 MW.