Longest time to build a power line

The longest time to build a power line is nine years. Costing around $1 billion, the Inga-Shaba Extra High Voltage D.C. Intertie project started in 1973 and was finally completed in 1982. The power line connects the Inga hydroelectric generating station with the mining intensive mineral fields within the province of Katanga (formerly Shaba) in the Democratic Republic of the Congo The total length of this high-voltage overhead transmission power line stretches 1,700 km (1,100 miles) from the mouth of the Congo river to Shaba deep in the interior jungle. Rated at 560MW using +/-500kV carriers, the project was originally budgeted to cost $250 million, but over-runs due to planning and armed conflict in the region pushed the ultimate bill to four times this amount.