EDF retrofits world's first tidal power station

French utility EDF has upgraded the original shaft seals at Brittany’s 240MW La Rance Power Plant in France, the world's first tidal power station.

The plant’s original shaft seals were made of an ultra-high molecular weight polyethylene (UHMWPE) and carbon graphite material.

Following successful trials, EDF replaced the shaft seals with Thordon’s SXL polymer radial shaft seals.

“For the EDF plant, we came up with an improved radial seal design that would fit into the existing housing...Initial trials were a huge success,” said Axel Swanson, Thordon Bearings’ business development manager - Hydro, Pump & Industrial.

According to Thordon, the SXL seal is unlike traditional shaft seals in that the elastomeric polymer material used is specifically designed to optimise performance.

Have you read?
Pioneering tidal power project announced for the Philippines
HydroWing creates new barge to cut costs of tidal energy technology

Operating parameters for Thordon SXL segmented shaft seals are generally similar to those for carbon graphite or phenolic seals in terms of maximum interface pressure and almost always reduce leakage.

Thordon's seals can also be designed for use in either radial or axial sealing systems.

EDF's La Rance Power Plant is one of the world's largest tidal power stations, with 24 turbines and a peak output of 240MW. Its annual power output is about 500GWh.

When the La Rance facility opened in November 1966, it was the world’s first-ever tidal power station. It remained the world’s largest until 2011, when South Korea’s 254MW Sihwa Lake Tidal Power Station started operations.