Tapping the power tides provide


SOLAR ENERGY:TWO COMPANIES, one based in California and another based in Switzerland, are competing to develop artificial islands delivering zero-carbon solar power and other useful outputs such as clean drinking water.

Californian start-up GreenFix’s floating islands use solar thermal devices and ocean thermal energy- conversion technology.

The giant islands would be between one and three square kilometres in size, the company claims. Its conversion technology would take advantage of the difference in temperature between surface ocean water and colder water deeper in the ocean.

Energy is produced by a turbine powered via a heat- exchanger loop that lowers the pressure by vaporising the water. Water could then be driven around a loop running across the island.

Meanwhile islands developed by Swiss firm Nolaris will measure up to five square kilometres. It’s currently working on a prototype in the United Arab Emirates.

Its concentrating solar panels will be able to produce steam, electricity, cold air and hydrogen. At its peak the prototype will be 80m in diameter and will produce about 0.5MW of electricity. However, it’s expected the full-sized island would produce at least 1GW of power.

Tapping the wind power tides provide

TIDAL ENERGY:DUBLIN-based tidal energy firm OpenHydro is making significant progress in commercialising its technology and operations, having dramatically reduced the time it takes to manufacture and deploy them.

Having gone from making its first turbine by hand in Co Louth, the company has now developed a supply chain that sources components from around the world, the company’s chief executive James Ives told an audience at the Institute for International and European Affairs.

Working with suppliers in China, South Africa, North America, Europe, the UK and Ireland, it now has a production line that can build them to the highest standards of quality.

This has seen the time it takes to manufacture a turbine reduced to about eight weeks, whereas the first one took nine months to make.

The second stage in its commercialisation process has had a dramatic impact on the time it takes to deploy one of its turbines on the seabed using its innovative €5 million installation barge.

OpenHydro initially set a target of deploying a turbine within six hours. Any longer than that would mean that the direction of the tide would change and its engineers would have to alter the turbine’s position on the seabed. But it actually managed to do so, safely and securely, to almost pinpoint accuracy, and correctly aligned the turbine with the flow of water within 20 minutes.

“This has had a transformational impact on the economics of installing our turbines. We have gone from a potential cost of €24 million to install a 1MW turbine to the point where we have installed one in Nova Scotia, Canada at a cost of €3 million. So we’ve taken a huge amount of cost out of deploying one of these.

“You could have more than one installation barge in operation so that installing a 100MW array of our turbines could be done quite quickly through a very flexible process at the lowest possible cost,” he said.

Currently optimising its technology for French power company EDF, OpenHydro is also aiming to deploy its tidal turbines in Scotland, the Channel Islands and the US, in addition to the ones already in operation in Canada and Scotland.