sectoral economic costs and benefits of ghg mitigation - IPCC

Renewable Energy
Greenhouse Gas Mitigation: The Perspective of Small Island
Developing States
Oliver Headley
Summary
Small island developing states (SIDS) are especially vulnerable to the effects of global warming;
these include sea level rise and the increase in the number and intensity of hurricanes. In
February 2000, representatives of some of the islands in the north eastern Caribbean met in St
Martin and discussed the need to set up a fund to cover the costs resulting from damage inflicted
by hurricanes since the insurance companies were increasingly unwilling to give coverage for
this risk; for example, the Barbados Light and Power Company (BL&P) is now unable to obtain
insurance cover for the poles of its distribution system. We therefore have to adopt a strategy
where we demonstrate that clean technologies may be employed at reasonable prices, or as
happens in the case of wind energy, at a price lower than polluting technologies such as coal. By
this method, we may be able to persuade the major emitters of carbon dioxide (CO 2 ) and other
greenhouse gases to adopt these technologies instead of those which have a major negative
impact on the environment. In the southern Caribbean, Curaçao installed a 3 MW wind farm in
1994 and will be opening another one of 9 MW in May 2000; Barbados obtains about 24% of its
primary energy from renewable sources, mainly sugar cane bagasse and solar water heaters.
India has already made considerable investments in wind energy and if we can persuade the
Chinese to adopt renewable and non-polluting technologies in place of their current massive coal
consumption practice, a major source of global warming will have been eliminated. From the air,
as an American visitor remarked, a low-lying tropical island “looks like a carpet spread in the
sea”, hence loss of territory to sea level rise is a problem.
Newer technologies of direct application to tropical islands have to be developed and
demonstrated. One of the most significant of these is Ocean Thermal Energy Conversion (OTEC)
where the warm water of the tropical ocean surface is used to vaporize a low boiling fluid such as
ammonia or propylene and this vapor is expanded through a turbine to give mechanical power
which is converted to electricity in a generator. The vapor is then condensed back to liquid using
cold water from a depth of 600 to 1000 metres and the cycle is repeated. The largest OTEC plant
so far operated is a 135 kW system in Hawaii and to prove the technology we will need to
operate one of 3 to10 MW in order to make the heat exchangers, turbines and other components
reliable. The warm tropical oceans have a surface area of several million square kilometres, this
power source is therefore capable of yielding terawatts of base load power. The fact that this
surface water is the power source of the hurricanes that devastate islands and coastal areas in
tropical and subtropical regions lends a certain poetic elegance to this technology which also has
spin-offs in marine-culture, desalination, district cooling and possible reef cooling to alleviate
coral bleaching. Curaçao is now looking into the feasibility of using cold deep ocean water for
space cooling and Dennis (1999) has considered the feasibility of using this technology for
greenhouse cooling in Barbados, St Vincent and Dominica.
Small Islands and Global Warming
There is now little doubt that the increase in atmospheric carbon dioxide (CO 2
) from the burning
of fossil fuels is the major contributor to global warming. Tropical cyclones are expected to
increase in frequency and severity as the surface temperature of the ocean rises. Table 1 lists the
intense hurricanes of the Caribbean /Atlantic region for the past twelve years.
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