Spain is on track to out-distance its European counterparts on the EU’s 2020 renewable energy targets, and it occupies a potentially pivotal role in the transmission of renewable energy to the rest of Europe. WindEnergyUpdate speaks to Miguel de la Torre, a senior engineer at Red Eléctrica de España, Spain’s grid transmission operator, to learn more about its recently-published transmission strategy and what it means for the wind energy sector.

By Rikki Stancich in Paris

WindEnergyUpdate: What are the key transmission issues in Spain at present?

Miguel de la Torre: Over recent years, three special projects were undertaken, with a joint investment of one billion euros, which are due to be commissioned in the period 2011-2014. 

The first is the new interconnection with France, which is classified as of high-priority interest by the European Union. This interconnection will allow the present interconnection capacity between both countries to be doubled.

The 70 kilometres section that crosses the border will be buried underground by means of a ditch system and will be of direct current (DC). The project has a global budget of 700 million euros, half of which will be contributed by Red Eléctrica. 

The second is the Rómulo Project, the DC submarine interconnection between Spanish peninsula and the Balearic Islands. This project is to assure and improve the reliability of the electricity supply and to promote competition regarding the generation of electricity on the Islands. The project, which has a budget of 420 million euros, will be commissioned in 2010-2011. 

The third is the Mallorca-Ibiza connection which, with an estimated investment of 225 million euros, will be the longest alternating current (AC) submarine link put into service to date, being a reference at a world level.

WindEnergyUpdate: What kind of investment is needed and how will this investment be apportioned within Red Eléctrica’s strategic five-year plan ?

Miguel de la Torre: Earlier this month, Red Eléctrica de España presented the Group's strategic plan for the 2010-2014 period, as well as the consolidated results for 2009.

The strategic plan considers investments of 4,000 million euros in the transmission grid over the next five years, which, together with those carried out in 2007, amounts to an investment figure of 6,000 million euros for the period 2007-2014 (the infrastructure plan 2007-2016 considers an investment of 8,000 million euros for the same period).

WindEnergyUpdate: What other strategies are highlighted in the plan?

Miguel de la Torre: The plan also considers the reinforcement of grid meshing and the international interconnections, not only to increase the capacity and to improve the quality and security of supply, but also to contribute to the operation of an integrated and competitive electricity system, where the integration of renewable energy is facilitated, and losses and system costs are reduced. 

In this sense, the cornerstone of Red Eléctrica's strategy for the next five years is to consolidate the role of the company as TSO, implementing the necessary investments to be able to adapt to the changes within the Spanish electricity sector and also acquire those transmission assets which are not currently owned by Red Eléctrica. 

Red Eléctrica is responsible for the technical management of the Spanish electricity system. As the owner of 99% of Spain's high voltage power transmission grid, it is the only company that specialises in the transmission of electricity in Spain.

For this, Red Eléctrica's principal mission is to guarantee the continuity and security of the power supply and to properly coordinate the production and transmission system, performing its functions in coordination with the operators and clients of the Iberian power market based on the principles of transparency, objectiveness and Independence.

Red Eléctrica also acts as the operator of the insular and extrapeninsular power systems.

WindEnergyUpdate: What are the challenges associated with bringing more renewable energy online and how is Red Eléctrica resolving these?

Miguel de la Torre: The production of wind energy presents some unusual features which are mainly associated with its uncontrollable nature. This factor makes it necessary to have a backup power system of sufficient capacity constantly available. Such backup power must be provided by other sources of energy.

This feature means that the forecasting, tracking and control functions related to this type of generation must be as accurate as possible. This is achieved through tele-metering of wind farm output and it allows the electricity system to be operated appropriately with regard to safety and in an economic fashion - similar to power stations operating under the ordinary regime.

To integrate renewable energies into the electrical system, Red Eléctrica has started up a Control Centre of Renewable Energies (Cecre), a worldwide pioneering initiative to monitor and control these energy resources.

Cecre allows the maximum amount of production from renewable energy sources, especially wind energy, to be integrated into the power system under secure conditions.

Cecre is an operation unit integrated into the Power Control Centre (Cecoel). The generation of the renewable energy producers, which have been set up in our country are managed and controlled by Cecre.

With Cecre, Spain has become the first country worldwide to have a control centre for all their wind farms of over 10 MW.

A lot of electricity produced in Spain has a renewable origin, as evidenced by records of wind energy. On 24 February 2010, the wind power production reached a new maximum high of instantaneous power, reaching 12,916 MW at 11:20 am. The last record was 12,880 MW on 5 February 2010.

In addition, a new record was set for hourly wind power production with a value of 12.843 MWh, between 11:00 am and 12:00 am. The last record was 12.790 MWh on 5 February 2010.

Also, during the early hours of 30 December, a new record of wind power energy was reached. At 3:50 am wind power generation covered 54.1% of the demand.

WindEnergyUpdate: When it comes to grid congestion, what priority do renewables have?

Miguel de la Torre: Renewable energy has priority of dispatch, which means, that in case there is congestion in the system due to, for example excess generation in an area, conventional generation or CHP plants must be reduced first and only in case it is not enough to solve the congestion, as a last resort, curtailment instructions may be sent by the CECRE to the renewable energy plants. 

WindEnergyUpdate: How will the new high voltage line between France and Spain establish Spain as an energy exporter to the rest of Europe and ultimately benefit Spain’s wind energy sector?

Miguel de la Torre: To be an energy exporter, Spain needs to strengthen their electrical interconnections with France. With the new high voltage line, which will connect Santa Llogaia (España) with Baixas (France), power sharing with the neighboring country will increase from 1,400 to 2,800 MW.

A new 400 kV line will double the actual interconnection capacity to reach 6 %, which would mean an improved security of supply and, above all, an improved stability of the system by strengthening its link with the European system.

The new interconnection will guarantee an increase in the development of wind energy and likewise, its integration and management under secure conditions. Only with the backing of a solid and sufficiently meshed grid will we be able to continue incorporating wind generation into our energy mix.

The aim is that the exchange capacity with France will represented 10 %, as advised by the European Union.

The revenues of the company are set annually by the Spanish Ministry of Industry and they come primarily from the transport activity and the operation of the system.

The revenues of transportation depends critically on the new facilities which are put into service each year and changes in the prices. On the other hand, the incomes from the operation of the system are also set annually based on cost justification made by the company on this activity.