Endesa has some repowering experience with wind plant. It repowered the 5.28 MW Los Valles plant in the Spanish Canary Islands a year ago, bringing its capacity to 7.65 MW. Six 180 kW wind turbines made by MADE, a former subsidiary of Endesa, and 42, 100 kW machines from the long since defunct US manufacturer American Wind Power (later named Kenetech) were replaced using nine 850 kW units from Gamesa Eólica.
"Replacing old machines for new ones needs to be economically viable," says Miguel Ángel Garcia of Endesa's renewables division, Endesa Cogeneración y Renovables (ECYR). "That means production from your existing wind plant has already paid back investment costs or that wear and tear on your existing machines means you're not producing enough."
In Tarifa, the Sociedad Eólica Andaluza consortium, with ECYR owning the largest stake at 46.67%, is replacing over 200 old 100-180 kW machines from MADE, Ecotècnia and AWP at its 30 MW Pesur-E3 complex. Repowering is coming after payback was reached in 2006. The consortium is finalising negotiations for 2 MW turbines after closing its call for bids last month. The repowered complex will more than double its output to 74 MW without requiring investment in new grid infrastructure.
ECYR is also the first wind company to gain approval to repower in Galicia, where 330 kW MADE machines will be replaced by 2 MW turbines at its 32 MW Barbanza and 24 MW Bustelo wind plants. Capacity at these plants will not increase.
With more than 12,000 MW of wind capacity now online in Spain, some of the country's regional governments are increasingly giving preference to repowering projects to optimise the space and grid infrastructures already used by existing wind plant and to reduce the visual impact of turbines. In Navarra, the regional government has gone so far as to practically limit all new development to repowering and research and development projects. "Wind capacity has practically hit the ceiling given environmental restrictions," said the government in its official bulleting last month.
Spain's dominant developer, Acciona, which has its headquarters in Navarra, said its plans for the region centre on repowering using the company's in-house 3 MW machine, currently under development. Initially, it will replace 500 kW machines and, later, 600 kW and 1.5 MW units.
But with over 90% of Spain's current installed capacity still less than eight years old and payback on plant investment taking up to 15 years, "A large scale repowering market is unlikely to really get started for another four or five years," says Garcia.