ELEMENTOS JURIDICOS NECESARIOS PARA EL ESTUDIO DEL CASO

5.3.5.1. Background: Use of Energy in Barbados’ Sugar Industry

Given that the year 2007 will likely mark the phase out by the World Trade Organisation of the preferential rates paid for sugar to the former colonies of the European Union, the sugar industry in Barbados faces an uncertain future. In addition, Barbados’ costs of production are much higher than the world market price of sugar, such that there is now a need to maximize the value derived from sugar cane.

Sugar production is one of the few agricultural processes where the energy output is greater than the input. It was therefore recognized that it should be possible to use the excess energy, most of which is contained in the bagasse (the waste plant material after the cane has been ground), to produce electricity for sale to the national grid.

In a traditional sugar factory, there is little attempt to optimise the process, so that the energy contained in the bagasse is transformed into a saleable commodity. Traditionally, the sugar factory burned bagasse and its boilers produced steam for generating electricity used by the factory, and processing the sugar cane into sugar. A large fraction of the energy is used to evaporate water from the juice to concentrate it to the point where sugar crystallization occurs. Since this requires low pressure steam, and because the price received for electricity by the sugar factories was not high enough to provide an incentive, no serious attempt has previously been made to generate high pressure steam for efficient electricity generation (Headley, 2001).

In the year 2000, Barbados produced 537,000 tonnes of cane and 58,333 tonnes of sugar.

5.3.5.2. The Development of Cogeneration

In recent years, efficient process engineering developed by the French firm SIDEC separated the generation of electricity and process steam from the other activities of the sugar factory and made them into a separate entity: a co-generation plant. Since bagasse is only available during the crop season for about four months per year, the co-generation plant has to use another fuel for the other eight months. SIDEC was originally setup in the 1980’s to improve the utilisation of French coal, hence they use coal as the second fuel in most of their co-generation plants. More than 35 of these projects are operating in France, including some at mills that process sugar beet. This technology is also used in the overseas departments of Réunion, Mauritius and Guadeloupe.

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The French plants have proven to be quite successful, such that in the year 2000, 20% of electricity (132 MW) generated in Mauritius was derived from bagasse. After several years of negotiations, in 1991, the French initiated their Bagasse Energy Development Programme. On Réunion, the total installed capacity is 437 MW, of which 126.6 MW is hydro and 118 MW is bagasse/coal. Réunion produces about 2 million tonnes of sugar cane per year, which gives 640,000 tonnes of bagasse/year. With a calorific value of 7700 kilojoules/kg, this is equivalent to about 120,000 tonnes of fuel oil.

Guadeloupe, which in the year 2000 produced 564,000 tonnes of cane, 56,299 tonnes of sugar, and 180,000 tonnes of bagasse, saw Bagasse/coal generating capacity of 64MW, such that 7% of the island’s energy was generated from bagasse (Headley, 2001).

The Government of Barbados has sent representatives to visit the cogeneration plant in Guadeloupe. To date, every effort has been made to make the cogeneration plant as noiseless and emission free as possible. Plants are outfitted so as to facilitate maximum combustion of the bagasse. 500,000 tonnes of cane per year yield about 5000 tonnes/year of fly ash, which is sold as a fertilizer since its phosphate content is high, making it excellent for acidic volcanic soils, such as is found in Guadeloupe. During the combustion of coal, a moving grate is employed such that the bottom ash falls to the bottom of the furnace. 160,000 tonnes per year of coal gives about 10,000 tonnes/year of bottom ash, which is used as the sub-grade in road making and in cement block production. About 800 tonnes/year of fly ash are also produced, which is now being investigated as a cement additive.

A low sulphur coal from Columbia is used to keep down emissions of sulphur dioxide; and emission of nitrogen oxides (NOx) is low for both bagasse and coal since this can be controlled by careful choice of combustion conditions.

Local environmental regulations require that records be kept of all their emissions and they normally are well under the required maximum values.

5.3.5.3. Barbados’ Investigations into a Local Cogeneration Plant

The Barbados sugar industry is now considering setting up one new factory and phasing out the three existing old factories. The peak electricity demand in Barbados reached 124MW in 2000, and the Barbados Light and Power Company (BLPC) is also looking at their increased electricity demand and ways of meeting it.

The Government and BLPC discussed the prospect of jointly setting up a 60 MW co-generation plant next door to the proposed new factory, rather than set up more diesel generators in 2003 to meet the growing electricity demand. However, given the uncertainty of the future market for Barbados’ sugar, the Government has delayed their decision to construct the new factory, such that BLPC is proceeding with plans for the installation of a new low speed diesel station, the first phase of which is a 30MW unit in 2003 (Personal Communication, Peter Williams, Senior Planning Engineer, BLPC).

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Should the government and the sugar industry be persuaded that a new sugar factory should be constructed, the cogeneration plant should be built next door to it. And should the electricity demand continue to grow, and enough land be retained to produce about 550,000 tonnes of cane, then a cogeneration plant on the scale of the Guadeloupe installation would be feasible. One marked difference, however is that since Barbados aims to keep its emissions to a minimum, the Government of Barbados would like to find an alternative to coal as the alternate fuel for any cogeneration plants constructed. At the moment, virtually all of the electricity used in Barbados is made in thermal plants burning fossil fuels such as fuel oil or natural gas, and electricity generation costs are about $55 US/MWh. Therefore, in searching for an alternate fuel, projected costs of generating electricity by co-generation must at least match this present cost. Barbados has looked at the possibility of utilizing natural gas as an alternate, which has to date been unsatisfactory due to high associated costs. Progress on this issue, and the final alternate fuel selected, however, will likely be guided by fuel cost, since the construction of a local cogeneration is seen as crucial both for energy generation and the continued production of sugar.