About

Like most isolated territories, French Polynesia relies heavily on imported fossil fuels for electricity generation. This dependence makes the country particularly vulnerable to fluctuations in fossil fuel prices and stocks.

In its energy transition plan, the Polynesian government has set a target of 75% renewable energy in Polynesia’s electricity mix by 2030 .

The region has great potential for solar energy production, with constant high levels of annual sunshine.

However, a number of constraints complicate installations, including

  • Reduced surface area
  • Complex access to land (conflicts of interest, undivided management)
It’s essential to find new areas in which to install renewable energies. The lagoons of high islands and atolls seem to be ideal areas for solar panels. They :
  • Have a large surface area
  • Part of the public domain
  • Are protected from the climatic conditions of the open sea by coral reefs

Polynesian lagoons are covered in coral...

Coral is made up of numerous polyps, small anemone-like animals that often form colonies. The coral is in symbiosis with a microscopic alga present in the polyp’s tentacles, the zooxanthellae, which provides 70 to 90% of its energy to build its carbonate skeleton 1. Against a backdrop of global warming, the global temperature of the oceans is set to rise by 1 to 4°C by 2100 2, leading to the extinction of at least 70% of coral reefs 3. Coral reefs are home to a rich biodiversity. They represent only 0.01% of the ocean’s surface, but are home to 25% of marine biodiversity. These heat waves will increase the frequency and intensity of coral bleaching events4.

What is coral bleaching?

Scientists have considered a number of ways to help coral in its fight for survival in the face of the consequences of global warming, including assisted genetic selection, coral transplantation and predator population management…5

What coral restoration techniques have scientists identified?

In previous global coral bleaching events, heavy cloud cover limited coral bleaching, while water temperatures were favorable for the onset of bleaching 6. Following these observations, numerous research projects explored this hypothesis and confirmed that temporary shading can help corals survive marine heat waves 7-10.

Thus was born the collaboration between Total Energies, CRIOBE and the city of Tumaraa to develop a pilot co-design project for floating photovoltaic systems and to monitor their effects on corals

References

1.Grottoli, A.G., Rodrigues, L.J., Palardy, J.E., 2006. Heterotrophic plasticity and resilience in bleached corals. Nature 440, 1186–1189.

2. Pachauri, R. K. & Meyer, L. A. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. (2014).

3. Pörtner, H.-O. et al. The ocean and cryosphere in a changing climate. IPCC special report on the ocean and cryosphere in a changing climate ,1155, 10–1017 (2019).

4. Donner, S. D., Skirving, W. J., Little, C. M., Oppenheimer, M. & Hoegh‐Guldberg, O. V. E. Global assessment of coral bleaching and required rates of adaptation under climate change. Global Change Biology11, 2251–2265 (2005).

5. Bostro¨m-Einarsson L, Babcock RC, Bayraktarov E, Ceccarelli D, Cook N, Ferse SCA, etal. (2020) Coral restoration – A systematic review of current methods, successes, failures and future
directions. PLoS ONE 15(1): e0226631. https://doi.org/10.1371/journal.pone.0226631

6.Hughes, A. D. & Grottoli, A. G. Heterotrophic compensation: a possible mechanism for resilience of coral reefs to global warming or a sign of prolonged stress? PLoS One ,8, e81172 (2013).

7. Mumby, P. J., Chisholm, J. R. M., Edwards, A. J., Andrefouet, S. & Jaubert, J. Cloudy weather may have saved Society Island reef corals during the 1998 ENSO event. Marine Ecology Progress Series 222, 209–216 (2001).

8.  Butcherine, P. et al. Intermittent shading can moderate coral bleaching on shallow reefs. Frontiers in Marine Science 10, (2023).

9. Coelho, V. R. et al. Shading as a mitigation tool for coral bleaching in three common Indo-Pacific species. Journal of Experimental Marine Biology and Ecology 497, 152–163 (2017).

10. Tagliafico, A., Baker, P., Kelaher, B., Ellis, S. & Harrison, D. The Effects of Shade and Light on Corals in the Context of Coral Bleaching and Shading Technologies. Frontiers in Marine Science 9, (2022).