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# Bapasse

# 15.

15. In recent years, interest has been renewed in making cane sugar mills energy selfsufficient and, thus, to produce surplus bagasse (the fibrous residue from cane crushing) for generating electricity to be used internally and for sale to the grid. Cane sugar mills exist in some 80 countries and most are not energy efficient: at best, they recover just enough energy from bagasse to meet milling season needs. The investments required in "bagasse projects" are those which considerably improve process steam economy and boiler efficiency, in effect obtaining the same amount of energy with less bagasse fuel. Bagasse dryers, condensing turbo-generators, efficient juice heaters and pre-evaporators can increase thermal efficiency and decrease process steam consumption considerably. Moreover, pelletizers and briquetting equipment can be used to densify surplus bagasse to be stored and transported safely and conveniently. This is espef-"' impor:3nt for ,ar-round electrical production where the markets for surplus energy are elet, utilities.

16. Davies Hamakua Sugar pioneered in this field with their mills in Hawaii. The F.U.E.L. sugar miX in Mauritius has a'so installed, at the pilot level, equipment for generating and densifying surplus bagasse, enabling it to sell year-round power to the grid. In 1985, the Bank conducted prefeasibility studies in Guyana and Ethiopia resulting in specific recommendations for bagasse projects in these countries.

17. In a typical bagasse project, economic return is based on revenues from selling surplus power and savings in internal use of petroleum fuels. In other cases, such as the project proposed for Ethiopia, the surplus bagasse product was intended to displace fuelwood in homes and later, to substitute for imported pulp and particle board feedstock. The impact of lower oil prices on project viability is fairly clear in the first case. It is less clear in the second case where the commodity being displaced is not petroleum-based. The Guyana and Ethiopia studies illustrate the differing potential impacts quantitatively.

18. Guyana's public electricity supply is almost totally dependent on imported petroleum. At present it suffers from a lack of generating capacity and system inefficiencies. Enmore, one of the country's 10 sugar mills, was chosen for a bagasse pilot project to demonstrate the feasibility of making the mill independent of diesel which it now uses and, at the same time, generating surplus power from bagasse for feeding to the public grid. The investments total US$ 10.5 million, most of it by Guysuco for mill equipment and modifications, and partly by GEC for a 14 km transmission line, transformer, and control equipment. The benefits of the project would be savings by Guysuco in diesel fuel (about 830,000 It/yr during the milling season) and avoided costs by GEC in diesel fuel for 24 GWh/yr of peaking power to be supplied by the Enmore mill. Calculated at the CIF value of diesel fuel at that time, which was " _5_ ' 42/barreL the economic rate of return for the project was an acceptable 21%. A drop in diesel fuel price by 25% reduces the ERR to 14% and, at half the 1985 price, the rate of return becomes only 5%. Thus, at present international oil prices, this particular project is not justified on the basis of fuel savings alone.

19. The Ethiopia project, proposed by an ESMAP study, consisted of investments in all three Ethiopian sugar mills to enable production of about 100,000 tonnes/yr of surplus bagasse.