Marine salvage expert, Nick Sloane, presented a keynote on iceberg harvesting on day two of the African Utility Week conference, where solutions from nature were explored to address increasing energy and water constraints.
“It sounds like a crazy idea but if we break it down, it is not so crazy after all,” Sloane on the idea of iceberg harvesting. His address followed director of water and sanitation in the City of Cape Town Peter Flower’s presentation on the water crisis in the city.
Flower told delegates the city still needs to reduce consumption to 450 million litres of water per day to keep Day Zero at bay. With the current usage at 500 million litres per day, the situation remains dire despite measures employed by the city to reduce consumption.
According to Captain Sloane the answer may just be in “mother nature’s icebergs” – a total of 140 000 icebergs to be specific – drifting in the southern oceans and melting. Harvesting icebergs, he said, can help provide at least 20% of Cape Town’s water needs.
He told delegates icebergs break off in Antarctica and hold some of the purest quality water that is between 15 000 and 20 000 years old. “About 2000 million tons of ice are breaking off every year,” he said.
The idea is to use the current system to guide these icebergs towards the Cape. “So, they are coming our way, we just need to know how to deal with it.” Sloane said the iceberg can be captured in the area around Gough island and will ultimately have to be guided and moored about 40 km offshore from St Helena island to be harvested.
He said they will then have to “create a saucer to capture the melting water that can deliver up to 60 million litres per day”.
With milling this volume can increase to 150 million litres a day that is then pumped into tankers and ferried to land where it will be treated before it goes into the water system.
“So, with 4 to 6 of these tankers 150 million litres can harvested per day for one year.” According to Sloane this is something that can be viable. “Can it be achieved? Well we are looking into it.”
Contribution by Alicestine October
(First published on our sister publication ESI.com)