page_title: Mew Island Lighthouse
section_title: LED system
hierarchical_section_title: Mew Island Lighthouse / Mew Island / LED system
caption_attribution_description: English: Mew Island Lighthouse
context_page_description: Mew Island Lighthouse is an active lighthouse within the Copeland Islands of County Down in Northern Ireland. The current 19th century tower is the last in a series of lighthouses that have been built in the islands, which have helped to guide shipping around the archipelago, and into Belfast Lough.
  A number of different fuels have been used as a light source including coal gas, paraffin and diesel to generate electricity. In 2015, the Commissioners of Irish Lights who operate the lighthouse replaced the hyperradiant Fresnel lens optic with a flashing LED system that only uses solar power. This large optic was then preserved and is now on display in the Titanic Quarter of Belfast as a visitor attraction known as The Great Light.
context_section_description: A temporary light was displayed until 2015 when a solar powered LED system was commissioned, this uses flashing illuminants to mimic the characteristic of the rotating lens. Its installation reduced the range from 24 nautical miles (44 km; 28 mi) of the hyperradiant apparatus to 18 nmi (33 km; 21 mi), and the focal height to 35 m (115 ft).  In 2017, this was enhanced with an additional fixed light, changing the light characteristic slightly from four flashes every 30 seconds, with "A new low luminous intensity fixed light [that] will be combined with the existing flashing light of higher luminous intensity in order to assist with acquisition of the light during the eclipse period." 
  The change to the LED system, and the removal of the optic from Mew Island has not been without criticism. Campaigners argue that the changes made were unnecessary and that there has been a lack of maintenance since the keepers left, with fixtures and fittings destroyed during the changeover. Protests at other Irish lighthouses marked for changes to LED lighting have also occurred, using Mew Island as an example of what can happen. At St John's Point also in County Down, campaigners argue that the LED beam is too harsh, compared to the traditional system. The response from the Commissioners is that the changes allow the removal of mercury which is a hazardous substance, and that the LEDs are more energy efficient allowing the use of solar power.
caption: The change to the LED light shown here in 2017, has been controversial
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