The electricity interconnection ratio

The value indicating the weight of the international interconnections of a country with respect to its installed power generation capacity is called the electricity interconnection ratio.

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In order to compare what percentage of a country’s electricity system is connected with its neighbouring countries, an electricity interconnection ratio is established, which is calculated by dividing the total import exchange capacity by the installed power generation capacity nationwide.

In 2002, the European Union recommended that all Member States should, by 2020, reach a minimum interconnection ratio of 10%, in order to eliminate systems that are basically ‘isolated’, provide mutual support and promote the Single Electricity Market.

Currently, Spain’s interconnection ratio, which is below 5%, is still far from the recommended target. If one considers that the real support to the Iberian Peninsula can come only from Central Europe through the border with France, the interconnection ratio of the Iberian Peninsula is 2.8%. Therefore, Spain basically can still be considered as an ‘electrical island’.

Strengthening interconnections represents the highest priority for the coming years in the development of the transmission grid. Investment in this infrastructure will be a priority, so therefore, for its full implementation, it will be necessary to comply with some fundamental premises, such as maintaining regulatory stability and adequate investment returns on investment, as well as a greater social acceptance of the facilities.

A higher electricity interconnection ratio increases the reliability and security of supply and increases support capacity between systems when faced with possible failures in the grid. It also increases the competitiveness among the interconnected countries and balances the price of energy, in addition to ensuring the better use and efficiency of generating technologies that use renewable sources.