A shining example of renewable energy at work, solar-powered marine lanterns or ‘aids to navigation’ routinely guide thousands of vessels safely through channels, ports and harbours around the world. As this technology continues to evolve, a range of ongoing refinements in the design, operation and capabilities of solar marine lanterns is translating into increased reliability and reduced operating costs that benefit those who use and maintain aids to navigation.
Advances in optics, batter ies, solar modules and energy management technology have all contributed to the reliability and effectiveness of today’s solar-powered lanterns, but among the most significant innovations has been the introduction of the light emitting diode (LED). In terms of mass an LED can be tiny, but as a versatile light source its impact is considerable – the LED is steadily replacing the incandescent bulb in many applications.
The LED’s efficient design means less power is wasted or lost as heat, and more energy is converted directly to light. With a lifespan of approximately 100,000 hours (or 27 years operating at 10 hours a day), today’s LED offers a considerably longer lifespan than its incandescent counterpart. LEDs can also produce any of the four specific international color chromaticities – green, red, amber or white – without filtering the output (and diminishing its brightness) through coloured lenses. Offering unparalleled durability, longevity and performance, the LED is a miniature marvel that, more than a decade ago, led to the development of another significant advancement: the self-contained LED lantern (SCLED).
With all components protected within a compact, durable casing, the solar-powered SCLED lantern has set new standards in convenience and reliability. And thanks to its compact form factor, the self-contained LED lantern is creating opportunities for even greater efficiencies by allowing for smaller and lighter buoys, quicker retrofits of existing buoys, easier upkeep, and a reduced need for specialised maintenance or elaborate equipment. In the United States, the US Coast Guard is in the process of replacing older, trouble-prone incandescent lanterns with the compact labour-saving SCLED lanterns. Though both alternatives cost approximately the same initially, SCLED lanterns offer considerable advantages through greater reliability, longer operating life, and reduced maintenance.
The end of an incandescent era
Many of the incandescent solar lanterns still in use date back to the 1960s, making them susceptible to a growing range of problems. Incandescent bulbs burn out frequently, mechanised bulb-changing gear breaks down from time to time, and the large separately mounted solar modules can become dislodged, obscured by bird leavings, vandalised or stolen. Water damage and corrosion can affect wiring, batteries and mechanical components, and the ever-present vibrations, especially on bell-equipped buoys, can cause bulbs and equipment to fail prematurely. In compar ison, a self-contained LED lanter n seals all components (including solar modules, batteries, lenses and sophisticated electronic controls) within a durable watertight polycarbonate/polymer or marine-grade aluminium housing. Thanks to the small but powerful LED, all the elements of a full solar-powered lighting system can be integrated within a compact, stand-alone device. The result is a powerful all-in-one lantern that can be transported easily, installed in minutes, and left to operate reliably for years, maintenance free.
Self-contained solar LED lanterns have survived prolonged submersions under ice, Category 5 hurricanes, collisions with cruise ships and container vessels, and in one unusual case, a yearlong 5,800-kilometre journey across the Atlantic Ocean – and continued working flawlessly.
The secure mounting options and integrated design of a selfcontained lantern also presents less of a temptation to thieves and vandals because the units are extremely difficult to steal or damage, and their custom, integrated components cannot be easily adapted to make-shift applications.