Fuelling by electricity
From 1850, the use of electricity would be studied by the “Service Central des Phares” (Central Lighthouse Service), which saw this as a miracle solution to the problem of lighting, as did its contemporaries.

The first time electricity would be used was at the La Hère lighthouse in 1863. However, it would not be widely utilised due to the difficulties involved in maintenance and servicing of the installations. It was still necessary to use large magnetic-electric groups driven by steam machines. The use of this equipment also meant high consumption in terms of water and personnel. In 1885, less than a dozen lighthouses functioned with an electric bulb.
Around this time, a large project which had been planned involving a luminous belt made up of 42 large electric lighthouses was again buried. A commission of enquiry limited investment in the lighthouses at Créac’h (Ouessant) - 1888, Goulphar (Belle-Ile) - 1890, Barfleur - 1893, Ile d’Yeu and la Coubre - 1895 and Eckmühl in 1897.
All of these lighthouses ran by the use of arc lamps fitted with regulators. The optics used all changed in order to accommodate small 0.30mm or 0.50mm focal fittings. Large machine rooms were built for steam machines and dynamos.
It would not be until the 1920s that real electrification of the equipment would take place. Bulbs had to be installed by a micrometric screw support system and their filaments would be made-to-measure in order to avoid large variations in the optics.
However, these changes were still slow and erratic. Initially, it would be the lighthouses and lights situated in towns or near the suburbs which would be changed. Later, the large lighthouses located in inaccessible areas would be fitted with batteries and diesel motors for recharging. Arc lamps would be substituted for incandescent 3000W or 6000W lamps (Nernst or Philips system) which were more practical and less costly.
However, in 1937, the new lighthouse at Créac’h would still be equipped with two arc lamps.