Under Construction


São Tomé and Príncipe Signs MoU For Ocean Thermal Energy Project

TagsEnergy Access, Finance and Investment, Renewable Energy
Thermal energy plant

São Tomé and Príncipe signed a memorandum of understanding (MoU) on 23 August with UK’s Global OTEC Resources and France’s Enogia for the development of a pilot ocean thermal energy conversion (OTEC) platform.

Known as Dominique, the 1.5MW floating facility will be installed in the Gulf of Guinea. 

Global OTEC will act as the technology and project developer, while Enogia will contribute the turbine and organic rankine cycle (ORC) power generation equipment. Completion is scheduled for 2025.

Dominique will be developed in the 160,000-square-kilometre exclusive economic zone surrounding the islands of São Tomé and Príncipe, which Global OTEC says is an untapped solar heat battery.

The OTEC plant will operate as a floating system that uses hot water from the sea surface to evaporate a low boiling point liquid. The hot steam produced will drive a turbine to produce electricity. Cold water from the deeper area of the ocean will be used to cool the steam and condense it back into a liquid state. The cycle can be repeated throughout the year, producing electricity without carbon dioxide emissions.

The facility's capacity could be expanded to 10MW in a second phase with additional platforms. 

“Compared to other renewable energies, [OTEC] is one of the few [that] allows stable output no matter the weather conditions and does not require extensive storage systems,” said Arthur Leroux, chairman of Enogia.

The Dominique project has been structured as a public-private partnership between Global OTEC, Enogia and SIDS DOCK as the institutional partner. The UN Industrial Development Organization (UNIDO) is partially supporting the project through a grant to SIDS DOCK.

SIDS DOCK – Small Island Developing States (SIDS) Sustainable Energy and Climate Resilience Organization – is a UN-recognised organisation established in 2015. The body represents 32 islands and low-lying developing states across the globe.

In July 2021, SIDS DOCK signed an MoU with Global OTEC to collaborate on developing and deploying OTEC technology, with São Tomé and Príncipe planned to be the first SIDS and least-developed country (LDC) to pilot an OTEC plant.

“In just one day, the amount of energy that the sun puts in the tropical oceans can run our islands for decades,” said Al Binger, secretary-general, SIDS DOCK. “The ocean is an inexhaustible renewable energy source and as long as the sun exists, we will have thermal energy in the ocean.”

According to Global OTEC, tropical ocean waters absorb solar radiation equivalent in heat content to that of about 250 billion barrels of oil each day.

The International Renewable Energy Agency says ocean energy has the potential to reach up to 10GW of installed capacity by 2030 globally.

In July, the contract for the environmental and social impact assessment report for the Dominique project was awarded to Lisbon-based consultancy AQUALOGUS Engenharia e Ambiente.

São Tomé and Príncipe wants renewable energy to account for 70% of its electricity mix by 2030.