Article by Peter Libretto, Design Engineer, Enertech
Lady Elliot Island is the southernmost coral cay of the Great Barrier Reef, Australia. The island lies 46 nautical miles (85 km; 53 mi) north-east of Bundaberg and covers an area of approximately 45 hectares (110 acres). It is part of the Capricorn and Bunker Group of islands and is owned by the Commonwealth of Australia. The island is home to a small eco resort and an airstrip, which is serviced daily by flights from Bundaberg, Hervey Bay, Brisbane and the Gold Coast.
Lady Elliot Island is located within the ‘Green Zone’ of the Great Barrier Reef Marine Park, which is the highest possible classification designated by the Great Barrier Reef Marine Park Authority. Marine National Park Green Zones protect the biodiversity within the Great Barrier Reef Marine Park by protecting important breeding and nursery areas such as seagrass beds, mangrove communities, deep-water shoals and reefs.
The Great Barrier Reef is one of the most important sea turtle habitats in the world, with Lady Elliot Island being a key part of that habitat. Every year between November and March the green and loggerhead turtles lumber up the same beach on which they were born more than 50 years ago. These turtles nest on Lady Elliot Island up to nine times in a season, laying between 80 and 120 eggs per clutch. About eight to twelve weeks later, young hatchlings leave their nests and head towards the ocean (January to April).
Solar and Storage on the Island
Around 6 years ago Peter Libretto from Enertech on the Gold Coast solar became involved in trying to reduce the 680l of diesel consumption per day on generators which provided electricity to the island.
After the initial 6 x German manufactured SMA sunny island 5048 inverters were installed with a Multi cluster box 12, 2 x banks of German 3200Ah and a 21kW solar array were installed, it was proof that renewables set up correctly was the answer.
Over the following years we have added a further 70kW of solar with SMA Tripowers on a distributed network along with a further 3 x more sunny Islands and 2 x German BAE Tubular Gel 3600Ah battery banks.
As a result, we have reduced the daily diesel consumption from around 680l/day to around 90l/day, this has had a dramatic effect on the island, aside of the peaceful silence that comes with a diesel generator not running, the financial saving benefits have allowed the Resort to fund other projects such as upgrading the desalination plant, complete refurbishment of all of the guest accommodation, restaurant, swimming pool, revegetation programs, on site composter and dive shop.
Due to the resounding success of the solar and storage projects on Lady Elliot Island, they decided to keep up with ever rising energy demand by increasing the battery storage capacity.
However, this time due to long lead times with Gel battery manufacturers, we took the step of introducing a new technology, the Aquion salt water battery.
Aqueous Hybrid Ion (AHI™) chemistry is made from abundant, nontoxic materials; the batteries contain no heavy metals or toxic chemicals and are non-flammable and non-explosive, making them the cleanest and safest batteries on the market.
AHI chemistry is composed of a saltwater electrolyte, manganese oxide cathode, carbon titanium phosphate composite anode, and synthetic cotton separator. The battery utilizes non-corrosive intercalation reactions at the anode and cathode.
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