INGENIEUR
Renewable Ocean Thermal
Energy-Driven Development
For Sustainability
By Dato’ Ir. Dr A. Bakar Jaafar
Director, UTM Ocean Thermal Energy Centre
O
cean Thermal Energy Conversion (OTEC)
is considered one of the most impactful
technologies during the first half of the
st
21 Century and beyond [1]. It is “a method of
converting part of the heat from the Sun, which is
stored in the surface layers of a body of water, into
electrical energy or energy product equivalent” [2].
That “energy product equivalent” could include
hydrogen fuel, an energy carrier, “… or an energy-
intensive commodity, including, but not limited
to, electro metals, fresh water, or nutrients for an
aquaculture;” [2]. Thus, OTEC could be considered
to be the most impactful technology since it would
generate revenues not only from generation of
power or renewable fuel but also other revenues
from the utilisation of the invaluable cold deep
sea water for district cooling [3], production of
temperate crops in the tropics [4], the culture
of seaweed such as “umi budou” (sea grapes)
[5], abalone [6], lobsters, prawns and other high
value marine produce and marine products [7],
extraction of lithium [8], and production of mineral
water [9].
The purpose of this article is to enlighten
readers on the impact of ocean thermal energy
conversion technology that would be brought
about for developing countries in the tropics to
progress toward hydrogen economy, especially
in the transport sector, and in other sectors as
well, should there be any change in the current
energy policy towards “true energy pricing” and by
removing the current energy subsidies.
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2019
VOL 77
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JUNE 2013
Compared with Other Sources of
Revenue, Pricing of Power from OTEC Is
Very Competitive
Although the amount of capital required for
investment in OTEC is high, as shown in Figure
1, the generation cost of electricity is the lowest,
other than that of salinity gradient, compared with
that generated from wave, wind, oceanic current,
biomass, tidal current, and solar photovoltaic (PV).
It is simply because the capacity factor of OTEC is
at least 95%, compared with that of tidal current,
only 20%, and where its capital requirement is the
lowest per unit of power generated. (See Table 1)
OTEC power would become more competitive,
than stated above, when the total capital
investment is spread out across its spin-offs
and revenue gained from the sale of raw deep
seawater for mineral water production, marine
culture of high value produce, growing of
temperate crops. Such OTEC spin-off industries
have been well developed, for instance, in the Big
Island of Hawaii by the Natural Energy Laboratory
of Hawaii (NELHA), and in Kume Island, Okinawa,
Japan [10].
Since the price of electricity from OTEC
could be lower than that of other sources, both
renewable and non-renewable, the production
of renewable hydrogen fuel by water electrolysis
would be competitive.
In the case of Malaysia, the OTEC power-plants
would be most likely sited at least 60 km from the