Power June 2023 - 10

GLOBAL MONITOR
it also plans to use the " knowledge and
expertise it has accumulated through its
offshore business and supply chain network, "
to boost OTEC commercialization.
Global OTEC also lauds OTEC's po2.
Global OTEC has designed what it says will be the first commercial-scale ocean thermal energy
conversion system. The 1.5-MW floating platform named Dominique is set to be installed
in São Tomé and Príncipe in 2025. Courtesy: Global OTEC
dustry are utilized, it is possible to design
and install successfully larger CWPs, "
which have posed a " key uncertainty for
OTEC, " OES said.
More recent notable projects include
Makai Ocean Engineering's land-based
105-kW OTEC plant at a research center
in Hawaii, and a 20-kW OTEC floating
pilot plant spearheaded by the Korean
Research Institute of Ships and Ocean
Engineering (KRISO) that began operating
in 2012. KRISO is now developing a
1-MW OTEC demonstration in the small
Pacific Island of Kiribati based on a trial
operation of a system tested in South
Korea's East Sea (near Pohang).
" The 1-MW OTEC demonstration
was designed for 24-degree-C seawater
temperature difference and has successfully
carried out in a trial operation
(output of 338 kW under operating condition
of 18.7-degree-C temperature difference)
in Korea, " Dr. Hyeon-Ju Kim, a
KRISO principal researcher, told OES in
a July 2022-published interview. " If the
demonstration of the 1-MW OTEC plant
near the equator is successfully carried
out in the future, competent professionals
can draw a positive outlook on the
scale of 10-, 100-, and 400-MW OTEC
plants gradually. "
OTEC development is also making
headway in Japan, where in 2016, a
100-kW OTEC demonstration on Kume
Island, Okinawa Prefecture, was connected
to the grid. OTEC power generator
Xenesys, which runs and maintains
the project for Okinawa Prefecture
(Kumejima Town), alongside project partners
Japanese transportation firm Mitsui
O.S.K. Lines (MOL) and Saga University,
confirmed the demonstration (Figure
3) is still operating. In March 2023, the
10
partners gained the backing of Japan's
Ministry of the Environment under a
technology development program for
" regional symbiosis and cross-sectoral
carbon neutrality " to expand the OTEC
project to a commercial-scale 1 MW
" by around 2026. " The effort will entail
manufacturing large, parallel-type titanium
heat exchangers equivalent to 200
kW of power generation and verifying
their performance from fiscal year 2022
to 2024, aiming to establish large-scale
heat recovery technology from seawater
for the commercialization of OTEC, the
companies told POWER.
MOL lauded OTEC's potential as a
baseload power resource that is " not
greatly affected by weather conditions. "
Another benefit it noted is that " even after
deep ocean water is used for power
generation, the water quality is unchanged,
and the temperature is still low
enough to be used for secondary purposes
such as fisheries, agriculture, and
air conditioning. " While MOL acknowledged
unsuccessful attempts globally to
commercialize the long-latent technology,
it said that its efforts " to quickly commercialize
OTEC in Japan and overseas, "
would be bolstered by a project to verify
its research from the Okinawa demonstration
at a project in Mauritius.
" Mauritius established a road map
to raise its percentage of renewable
energy to 60% by 2030, " the company
noted. " OTEC, which can reliably generate
power 24 hours a day regardless of
weather conditions, has great potential
in Mauritius, thanks to the island's advantageous
geographical location in the
Indian Ocean. Secondary use of seawater
after power generation can also help
other industries on the island. " MOL said
www.powermag.com
tential for small island developing states
(SIDS). SIDS often suffer high energy
prices, owing to a reliance on diesel
and other fuel imports, and face space
constraints to install adequate amounts
of wind and solar. Along with baseload
power, " OTEC can supply quantities of
cold water as a by-product. This can be
used for air conditioning and the nutrientrich
deep water can be used for aquaculture
and the creation of a sustainable
local economy, " said Neil Reynolds,
Global OTEC board director, who is also
a special advisor to the international organization
SIDS DOCK. " OTEC can also
be coupled with desalination for drinking
water and the production of ammonia
and green hydrogen, " Reynolds added.
Along with its first closed-loop barge
planned for São Tomé and Príncipe, off
the western equatorial coast of Central
Africa, Global OTEC is exploring OTEC
sites in the Turks and Caicos Islands
(TCI), an archipelago of 40 low-lying coral
islands in the Atlantic Ocean. " Having a
vast exclusive economic zone of ocean
space many multiples the area of their
land waters and being in the tropics,
TCI is well suited for OTEC, " the company
said. Global OTEC's desktop studies
have shown TCI possesses the ideal
combination of warm seawater all year
round and easy access to cold deep water
with continental shelves quickly falling
to 1,000 meters (3,281 feet) within 4
3. An ongoing 100-kW ocean thermal energy
conversion (OTEC) demonstration facility
owned by Japan's Okinawa Prefecture is slated
to be expanded into a commercial-scale
1-MW facility. Courtesy: Mitsui O.S.K. Lines
POWER | June 2023

http://www.powermag.com

Power June 2023

Table of Contents for the Digital Edition of Power June 2023