Mr. Panditharathne has passed out from University of Peradeniya as Mechanical Engineer in 1985 and he is having over 25years of experience in the field of Power and Energy. He is an experienced engineer in Ceylon Electricity Board and has served in several projects and power plants for the betterment of CEB and the country. Further, He is an active member of Institution of Engineering & Technology and Institution of Engineers Sri Lanka. Mr. Panditharatne has worked as a Project Manager of the Coal power project during last few years and has vast experience on coal power plant. He has actively participated at the execution of the project and has contributed lot to make the dream of coal power to become true 9 months prior to the schedule. Now Mr. Panditharatne is the Deputy General Manager of Norochcholai Coal Power Plant of Ceylon electricity Board.

Why did coal power caught attention of Sri Lanka?

Power generation in Sri Lanka until recently heavily relied on hydro power. With the escalating demand for electricity, bigger component of total power generation had to come from thermal energy because hydro power was running at its full potential. Thus, hydro power and thermal have switched their roles while their contribution as of now roughly adds to 40% and 60%. Average cost for a unit of hydro electricity costs approximately 3.50LKR while thermal costs 10.50LKR. Therefore, a low cost method of producing electricity has to be introduced. This is where coal comes in. Coal is widely available and cheap compared to sources of other forms of thermal electricity generation. Sixty percent of energy demand of USA is sufficed by coal power plants while our neighbour – India – produces 68% of the energy demand from coal power plants. In addition to this, coal reserves in the world are predicted to last 100 years or more. The technology has been around for a while and does not involve the huge risks as in nuclear power generation.

What parties were involved in funding the project and the construction activities?

The plant is situated in the village of Narakkalliya, 12km off the Palavi junction on the Colombo – Puttlam main road. Main contractor of the project is China National Machinery and Equipment Import and Export Corporation (CMEC), a semi government company of PRC. The project is carried out in the form of Design – Build – Transfer basis and the costs have been estimated at 455 billion USD. Poyry Energy Ltd of Switzerland acts as consultants for the project. Construction initiated in 2007 after having the inception stone laid in May 2006 by the President.

Plant lifetime is designed to be a minimum of 30 years and will cater for the based load. Availability is anticipated above 85%.

How does coal handling take place from the delivery to combustion?

Only high quality low sulphur bituminous coal is used as the fuel for economic and environmental standards and the supplies will be received from the countries such as Indonesia. Requirement of coal to generate 300MW will be 140 tons per hour.

Transportation and Unloading of Coal

Coal delivered will be unloaded to the barges at mid-sea, which then reaches storage facility of the site on conveyors stating near the shore jetty. The plant owns three barges – each capable of carrying 5000MT – and two tugs. Conveyor belt is capable of carrying 1500MT per hour. Samples of coal are taken from the load before sent to storage facility.

Can you briefly explain the operation of the plant?

The coal used in combustion will be first crushed to the size of 2.5mm and then ground until it becomes a powder by a pulveriser, before entering the 63-m boiler (sub-critical pressure, once reheat, natural circulation, single-drum, semi-out door, tangential firing, balanced draft, type) where the steam pressure will build up to 173 bars and temperature is 541°C. To minimize the impact on environment, the boiler incorporates “Low NOx burners.” We were also told that reduction of NOx could be realized through regulating the furnace temperature. In order to arrest, suspended particulate matter (fly ash) electrostatic precipitators are used.

What is the electrical output of the plant? Where is the electricity transmitted?

The project consists of three stages (300MW×3) and stage 1 is currently operational. Construction of stage 2 (600MW) is now under way. Once completed, the entire site will cover 92 hectares (242 acres). Each 300MW generator is expected to generate 2200 million units of electricity per year. Generating voltage is 20kv and for transmission, this will be stepped up to 220kV. The generators used are two – pole, cylindrical rotor type synchronous machines. Each has a closed circuit hydrogen cooling system to cool the stator core and rotor, including direct hydrogen cooling of field winding. Output of stage 1 will be transmitted via a 155km double circuit line to Veyangoda Grid Substation. Once stage 2 is completed, it will be connected to Anuradhapura Grid Substation. However, an additional intermediate switching station will be required at Chilaw for this purpose.

Obviously, there are going to be environmental concerns involved in coal power generation. What remedial measures have been taken to avoid those?

As mentioned above, Electrostatic Precipitators are used to remove the particulate matter in the flue gas. once the flue gas pass though a set of charged place electrostatically charged ash particles get attracted to the side plates and finally get collected at the bottom ESP.What it does is, subject the exhaust gas to a strong electric field and charges them. Afterwards, the charged particles can be attracted and extracted by charged plates in the system. Efficiency of the ESP system used in the plant is 99.8%.

Gas coming out from the ESP then is treated for sulphur content in the Flue Gas De-sulphurization Plant (FGD). Inside, the flue gas is allowed to move vertically while a strong ocean water spray is aimed at it. Sulphur Dioxide in exhaust gas will be absorbed by this method with an efficiency of 99%. After these two purification plants, final exhaust gas dispersed to the environment conforms to the environmental regulations.

Ash collected in the ESP is sold to cement manufactures that use it as a raw material in their industry. Leftover in the boiler bottom area, which is referred to as bottom ash, can be used to make bricks.

Lakwijaya Power Plant has a desalination unit to meet the plant's entire requirement of water. Also seawater is used to cool the steam in the condenser of the turbine plant. For this purpose is pumping to the condenser at a rate of 17.5 cubic meters per second and after condenser heat it is again discharge to the sea while maintaining a seven degree temperature difference between the seawater inlet and outlet . In this power plant ground water is not used in any form.

How did the plant affect dwellers in the area? What actions were taken to in resettling aspects and developing the suburbs?

Plant site spreads over 9928 hectares. Eighty families had to be resettled and relocated at Dalduwa – about 14 kilometres from the project site. Each family unit was provided, furnished house constructed on 20 perch land and additional 2-acre plot of land per family to carry agricultural activities. Overall, quality of life of the resettled people improved from the previous status. On our visit to the plant, we noticed that the road network near the project has improved, especially the Palavi – Kalpitiya road and the access road from Narakkalliya junction. Moreover, CEB statistics state that the plant generated over 300 direct and indirect job opportunities. We are lucky to have this kind of a new energy technology in Sri Lanka to meet the future energy demand on country without depending on the either related hydro resources and the diesel plants.