Thermal energy stored in tropical seas can be used to generate sustainable electricity. This energy is produced by utilising the natural temperature difference between the surface water and deep water. The OTEC system transforms the thermal energy into electricity. The system uses pipes into the deep sea and a small installation on land to generate electricity.
It concerns a closed system whereby the water outflow will be pumped back into the ocean at a depth where it does not adversely affect the fragile maritime ecological system, explained Bluerise Chief Executive Officer (CEO) Remi Blokker in an interview at his offices adjacent to Technical University Delft.
The deep sea surrounding Saba is ideal to install the OTEC system. Naturally, Saba’s underwater nature and the coral reefs will be taken into consideration during the laying of the pipes, said Blokker.
Because it is completely clean energy, it perfectly fits Saba’s vision as an eco-tourism destination and green island. With an OTEC system in place, Saba would be able to supply 100-per-cent-sustainable electricity, with the existing diesel generators as a backup.
The OTEC installation would provide three megawatts of electricity, enough to supply the entire island. The installation also could provide fresh water and cooling. The system works 24 hours a day, which is an advantage over solar or wind energy, which are limited to the amount of sunlight and wind. Pilot installations in Hawaii and Japan so far have proven successful.
The initial cost of the OTEC system is relatively high and requires a multi-million investment. However, the investment will repay itself in a couple of years, explained Blokker. In the long run it is cheaper than generating electricity in the current manner, via diesel generators. Diesel fuel has to be imported and the transportation cost is high. The transportation of fuel also presents a risk to the marine environment in case of an oil spill. The OTEC system does not require the use of fossil fuel.
Blokker emphasised that the OTEC system would be tailor-made for Saba. “This is an island solution which is meant to work for an island,” he said. Surrounding islands also can benefit from this enterprise. Technically, it is possible to transport the electricity via a cable to, for example, St. Eustatius.
A pilot study will first have to be executed in Saba to determine the specifics of this project. Blokker emphasised that setting up an OTEC system was a long-term project that involved a lengthy trajectory of studies, developing and engineering.
The initiative to propose Saba for this project came from the Second Chamber. Member of the Second Chamber André Bosman of the liberal democratic VVD party had invited Bluerise for a presentation, while Wassila Hachchi of the democratic party D66 had asked to schedule a date for a presentation to the Kingdom Relations Committee.
Bluerise specialises in OTEC and seawater air conditioning (SWAC) for buildings, as well as ocean ecoparks that utilise the ocean resource by means of innovative technologies for desalination, agriculture and aquaculture. The company provides consulting and engineering services to governments, project developers, energy companies and utilities.
Bluerise is active in several areas in the world, including Curaçao where it started to work on the Ocean Ecopark in 2011 together with Curaçao Airport Holding. The project is currently in the developing phase. The objective is to generate energy for the airport and the surrounding area, which includes the free zone Curinde and the data centre CTEX.
The Curaçao project will encompass a number of deep-cold-water applications. The OTEC plant will provide electricity while the Seawater District Cooling system will cool the airport building and surrounding facilities. The intention is also to set up various forms of agricultural and aqua-cultural companies to grow fresh food and fish.
Ocean Ecopark Curaçao was selected in 2013 as part of the prestigious international innovation platform Sustainia 100 Sustainability Guide as one of the 100 most innovative sustainable and impactful solutions around the world for its positive social, economic and environmental impact on local communities.
Oceanographic explorer and conservationist Fabien Cousteau, grandson of the famous French explorer, conservationist and scientist Jacques Cousteau, is Bluerise’s Ambassador. He is an avid supporter of the OTEC system: “OTEC is a clean energy source, a prime example of how to sustainably make use of our oceans without harming the marine environment,” he said.