Analyses

Coal-fried power plants

Why do we need coal-fired power plants?

* Growth rate statistics for GDP and electricity demand over the past few years show that electricity demand growth closely follows the growth of the economy. During the severe power crisis in 1996, GDP growth recorded a minimum of 3.8% but recovered to 6.4% in 1997. Economists estimate that the economy lost Rs 600Omn in 1996, largely as

* result of the power crisis. Apart from the sheer inconvenience caused by the 1996 crisis, such a large economic loss to the country cannot be allowed to recur. The expansion of electricity supply -has therefore become an urgent national priority.

* Sixty per cent of Sri Lanka's available hydroresources contribute 75% of the electricity on the national grid. With total electricity demand growing by some 8% annually, the nation will require 1,20OMW of new electricity generating capacity in the next 10 years, primarily for "base load," i.e. processes which require a continuous supply of electricity. Since the remaining 40% of hydroresources are insufficient to meet this need, other power sources must be found.

* Sri Lanka's inability to rely on one major source of power generation makes developing a strategic "fuel mix" necessary. However, while solar, wind and small hydroelectricity power plants can contribute to meeting the overall requirement, they cannot satisfy the base load demand. Smaller power plants are also less economical to install than larger plants, and have higher operating costs. Hence, large scale coal-fired power plants represent the most cost-effective way to expand power generation capacity for the future.

* Finally, coal power is already a global choice, providing over 40% of world's electricity needs. In particular, developing countries such as India, China, Malaysia, Indonesia, Thailand and the Philippines have large coal power plants, and are building more. Since coal power technology is already well established, Sri Lanka stands to gain from other countries' experiences.

How will Sri Lanka benefit from the new plants

* In the long term, Sri Lanka's power generation alternatives will be limited to either oil- or coal-fired power plants.

Proven oil reserves are expected to last for around 100 years and are mostly located in one area, whereas coal reserves are expected to last more than 400 years and are located all over the world. In addition, the unit cost of coal-generated electricity is lower and coal-power plants are more reliable, last longer and can be used for base load operation.

* Sri Lanka needs electricity at a competitive price to help drive its next phase of social, commercial and industrial development. By adding coal to the country's fuel mix, our reliance on oil will be reduced, and the fuel supply for electricity generation will be stabilized. Importantly, even in times of natural disasters, an uninterrupted supply will continue at a lower cost. Thus, coal power represents the most cost-effective as well as the most forward-looking solution to Sri Lanka's power generation problems.

* Sri Lanka will derive many secondary benefits from its coal power projects. The first power plant alone, once developed to its full 90OMW capacity by year 2010, will represent an investment of Rs60,000nin (US$90Omn). In addition to the significant improvements to the physical infrastructure, the project will provide 2,000 jobs during its 110-year construction phase and 500 permanent jobs in power plant operation and associated services.

How will the ecological impact be minimised?

* The recent decades of heightened concern for the environment have led to significant advances in the technology to reduce a power plant's ecological impact. Thus the technology used in Sri Lankan coal-fired power plants will be consistent with the state-of-the-art technology now used In coal-fired power plants in developed countries.

* Several measures will be employed to minimise the emission of the main air pollutants created by coal burning, Sulphur Oxides (SO), Nitrogen Oxides (NO) and suspended particles.

* The plant will burn low-sulphur coal in order to comply with SO limits.

* An Electrostatic Precipitator (ESP) with 99.3% collecting efficiency - the best currently available - will be installed to meet standards for particle emissions from chimneys.

* The reduction of NO emissions to meet the Sri Lankan Environmental Standards will be achieved by the combination of an appropriately designed furnace and using low NO burners.

* Smoke emissions from the power plant will be released from 150 metre (485 feet) tall chimneys.

*Sea water will be used as- cooling-water for- the coal opwer plants. By diverting the plant's water into the ocean, the sea temperature is expected to rise by 1.5'C over an area of 2.5 acres of the Indian Ocean. In India alone, the majority of the country's 60,OOOMW power plants divert their warm water into the ocean, but no biological damage

has been reported. aThe ash that remains after coal combustion will be used as a raw material to manufacture various products, including cement and bricks. The Puttalam Cement factory has already agreed to buy ash remains of one plant. It may also be possible to use the bottom ash as an aggregate in concrete or as a base material in road construction. aCoal will be conveyed from the ship to the shore along a 4.2km long jetty, supported by piers at 40 metre intervals. With the piers this far apart, the movement of sediment on the sea floor will not be disturbed. Hence, fears of sea erosion due to coal transportation to the power plant are unfounded.

Presidential secretariat Analyses

28 April 2000 Number I7
