Mentioned for more than a decade, the Swac of the Taaone hospital is in full assembly in Papeari, where the government visited this morning. The idea, already explored in Bora Bora or Tetiaroa: to go to draw water from 900 meters deep enough to cool the CHPF air conditioning and therefore to make significant savings in electricity.
Twelve meters each, 710 mm in diameter… Arrived by container from Italy, portions of the future Taaone Swac wait patiently on the shores of Phaeton Bay, in Papeari. It is there that, since the month of January, these enormous pipes have been welded together by “polyfusion”, weighted with concrete blocks, protected and gradually launched along a rail, where their tightness is still tested… Small sections – up to 650 meters long all the same – are already stored at sea, not far from the Teputa pass. When the last section – 2.4 km which will wrap around the bay – is completed, in June, the “pipe”, as the site technicians call it, will be towed outside the lagoon, and around Tahiti to the coast of Pirae.
It is there, facing the CHPF, that the Swac (Sea-water air conditioning or seawater air conditioning) will be submerged along the drop off and the reef, from 900 meters down to the coast. If all goes well, the pipe should allow, for 30 years, seawater to be pumped at 5 ° C to bring it to the hospital’s water air conditioning system, which will therefore be able to do without its coolers. so greedy in electricity. The water must then be discharged at around 12 ° C into the lagoon, which according to the preparatory studies will not suffer “any environmental impact”. An idea which, after more than a decade of feasibility studies, political procrastination or contested market attributions, is finally on the way to materialize. According to Roy Issa, project manager of Géocéan, a subsidiary of Vinci which won the tender for the maritime structure, the assembly site is already half finished.
This morning, in Papeari, President Fritch, surrounded by three ministers and representatives of the country’s and state administration, visited each workshop on the site. Each time with reassuring explanations on the modernity of the techniques used and the solidity of the final product. It must be said that the fenua is not its first experience in this area. In Bora Bora, where the Intercontinental installed the world’s first commercial Swac in 2006, the equipment has been out of order for 5 years now, and attempts at repairs have so far failed. That of Brando, installed in Tetiaroa from 2011, is well in operation, and its effectiveness is the subject of a study of the Country and the University. Polynesia, whose very steep drop-offs close to the coast are particularly suited to this technology, reaffirms its confidence in this new technology by ordering “the longest commercial Swac in the world” for the CHPF. 3.6 billion francs – including 44% in the country’s own funds, and State loans and subsidies – for 3.8 kilometers of installation. “We have no doubts about this equipment, explains Minister of Finance and Energy Yvonnick Raffin. The concerns of anchoring in Bora Bora gave us feedback which enabled us to review the technical processes ”.
Reconciling profitability and energy transition
According to the financing plan, the investment should pay off in “10 to 15 years”. It must be said that the CHPF weighs heavily in the electricity consumption of Tahiti and that its air conditioning represents more than 50% of the bill. The new system relies on pumps, but without a chiller, energy efficiency “Is multiplied by ten” specifies a specialist. Next October, when commissioning, and after a few weeks of final tests, 12 GWh of electricity consumption, or 350 million francs and 5,000 tonnes of CO2 equivalent per year, will disappear. And with them will evaporate 2% of electricity demand in Tahiti, which will therefore grab as many points in the penetration rate of renewable energies. “We have succeeded in reconciling energy transition and financial savings”, welcomes the head of the energy department, Pierre Bosq.
Country-wide targets – 75% renewable in the electricity mix in 2030 compared to 28.8% today – are still a long way off. But the Swac will at least unblock the meter, which tended rather, the lack of rain not helping, to drop in recent years. If other seawater air conditioning systems could be studied – for the administrative district surrounding the avenue Pouvanaa a Oopa, for example – the country wants above all to increase the number of projects. Calls for projects on photovoltaics, energy regulations for buildings, etc. “We are working both to reduce demand and to increase production of renewable energy”, says Pierre Boscq.