Case Study 2: Cables Enable Development of Valuable Project at Madrid Airport

Madrid's Brajas Airport is Europe's main airport for flights to Central and South America. When AENA, the Spanish airport authority, put in place a $3.5 billion project to double capacity up to 79 million passengers a year, three new runways were an integral element of the plan.

However, an existing 400 kV overhead transmission lines crossed the line of the runway. The transmission lines, owned by REE, Spain's main Transmission System Operator, were a key element of the grid serving the city of Madrid.

The importance of maintaining a stable supply to the capital meant the reliability and capacity of any solution was of the highest importance. The only technically feasible and cost effective solution was to replace the lines with 13 km of 400 kV cables in a tunnel under the new runways, with three parallel single core XLPE cables, each with a conductor cross-section of 2,500 mm².