Economic growth in Asia will require the construction of thousands of MW of new capacity
Although Asia has a need to add 700 GW of new capacity by the year 2010, the big question that remains is who will provide the financing
Douglas J. Smith
With double-digit growth, countries throughout Asia have a need for new electric power capacity. As industrial and commercial sectors grow and improve, they are quickly outstripping the existing power generating capacity. Asia as a whole is projected to need 720 GW of new capacity between now and the year 2010. Currently Asia has approximately 500 GW of installed capacity.
Today Asia accounts for approximately 50 percent of the world`s population and by volume is responsible for about 25 percent of the commercial activity worldwide. Asia currently consumes about 20 percent of the world`s total primary energy supplies. The area has 4 percent of the world`s proven oil reserves, 6 percent of its natural gas reserves and 27 percent of the proven coal reserves.
Unfortunately, these reserves are not evenly distributed in the region. Three countries: China, Indonesia and Malaysia own the majority of the region`s energy reserves. As a consequence, most of the Asian countries are heavily dependent upon fuel imports for electric generation. Figure 1 shows the growth of energy sources in Asia through the year 2020, while Figure 2 shows the breakdown by energy sources. With forecasts indicating that Asia has the highest economic growth rate of any region of the world, the market for electric power generation is tremendous. However, the big question that still has to be resolved is where the money will come from for financing new power plant development.
Regional power trends
According to a paper presented by Harza Engineering Co. at POWER-GEN Asia `94, the Philippines will need 21,000 MW of new capacity between now the year 2005. It is expected that most of the new capacity will be private power projects. Up until quite recently the Philippines` two main islands were plagued by power shortages and brownouts.
Although the Philippines` economy is estimated to be growing at an annual rate of 4 percent, the country is having problems in supplying sufficient electric power to keep up with demand. With current economic growth, the Philippines has a need to add around 9,000 MW of additional capacity by the year 2000 and 11,000 MW by 2005.
Up until 1993 the Philippines was plagued by shortages of electrical power which forced the country to schedule brownouts of up to 12 hours per day. However, with the addition of 1,100 MW of new capacity in 1993 and 1994, the Philippines has been able to reduce brownouts. According to official estimates, the brownouts were costing the country up to (US)$5 billion a year in lost economic activity.
In addition, the government is encouraging private power projects, especially build-own-operate. Private power is expected to supply most of the new Philippine capacity between now and 2005.
The National Power Corp. (NPC), the Philippine-owned company responsible for power generation and transmission throughout the country, is trying to lease many of the country`s existing thermal and hydropower projects to private companies. These leases are to companies who agree to rehabilitate and operate the power plants and sell the power and energy produced to NPC.
Several privately owned new projects are also under development in the Philippines. However, for constitutional reasons the projects must be developed by Philippine-controlled groups. As a result, local utilities and local project developers are active in these projects.
India is another country actively looking at the private sector to supply the country`s ever-increasing need for new electric capacity. Electric power generation and distribution is primarily handled by state government boards and corporations in India. India also has several private electric utilities and a number of central government corporations. National Thermal Power Corp., National Hydropower Corp., National Nuclear Power Corp. and Power Grid Corporation of India are all central government corporations primarily responsible for large regional projects. Table 1 shows the status of private power projects in India.
India`s central and state governments are now encouraging the development of private electric generation capacity and are implementing private power changes in legislation and regulation governing the power sector. As a result, it is now becoming easier to develop private power projects using international financing.
Developers of private power projects must involve state governments and the Central Department of Power if they are to successfully develop private power. In addition, clearances to begin construction are required from a number of state and central government organizations.
Pakistan looks promising
In 1958 the Water and Power Development Authority (WAPDA) was created to coordinate the development of water and electric power resources of Pakistan. Except for the Karachi service area, the electric power side of WAPDA has the responsibility for planning, constructing, operating and maintaining power generation, transmission and distribution facilities in Pakistan.
Karachi metropolitan area`s electric power is supplied by the Karachi Electric Supply Corp. (KESC). KESC`s generation capacity is about one-fifth that of WAPDA. However, KESC does exchange power with WAPDA whenever possible.
Due to financial constraints and the increasing demand for more generating capacity in Pakistan, WAPDA has been unable to keep up with demand. In addition, due to constraints on the construction of hydroelectric power projects, a shortage of electric power was experienced in the mid 1980s. The end result was the central government`s decision to invite the private sector to develop new power generation projects.
Under privatization, all of the power produced by private power plants is purchased by the government and pooled into the National Grid for transmission and distribution. The World Bank, together with co-financiers, are helping Pakistan to finance power generation projects. One of the projects that is being financed is the 1,292-MW Hub Power project.
There are several thermal power projects seriously being considered–including a 6×300-MW gas-fired, combined-cycle power plant at Sahiwal; a 350-MW oil-fired steam plant at Jamshoro; a 3,600-MW coal-fired plant at Gadani, which will burn imported coal; and a 2×210-MW plant at West Wharf, Karachi. However, financing of these projects is still under discussion.
Although the projects just mentioned have yet to receive financing, the following projects are actively being developed by private developers:
– the 584-MW Uch combined-cycle, low-calorific, gas-fired project
– a 450-MW combined-cycle, oil-fired plant at Jamshoro
-a 134-MW gas-fired, combined-cycle plant at Kabirwala
-the 350-MW Fauji plant at Hub and
-a 120-MW oil-fired plant near Lahore.
According to the National Development Finance Corporation of Karachi, there is more than 30,000 MW of potential hydroelectric power that may be economically developed in the northern part of Pakistan. However, only 15 percent of this has been developed.
The Pakistani government is actively promoting the development of private power and has implemented a package of incentives for private power generation projects. Although investors are free to propose the site, technology and fuel, approval for a project will depend upon the long-term availability of fuel, cooling water, infrastructure, environmental impact and the economics. Proposals for hydroelectric, solar, wind and geothermal power projects will also be considered by the government. Figure 3 shows the procedures for processing power generation projects in Pakistan.
In addition to the promotion of private power development, the government of Pakistan offers incentives to companies for self-generation. To accelerate the setting up of self-generation plants in industry, Pakistan is looking at enacting legislation similar to the United States` Public Regulatory Policies Act of 1978 (PURPA). This legislation would encourage small- to medium-scale power production in the industrial sector.
Combined-cycle power for Asia
According to GEC Alsthom Combined Cycles Ltd. in the United Kingdom, where a reliable long-term supply of natural gas is available, it is economically and ecologically advantageous to consider the use of gas-fired, combined-cycle power plants. A combined-cycle power plant can also be utilized to supply a variable load demand, which is often the need in Asia. In combined-cycle, the gas turbine can be used to provide fast initial load ramps, while the steam turbine can be utilized to follow load at a slower rate.
GEC Alsthom`s combined-cycle projects incorporate a 226-MW ISO-rated frame 9FA gas turbines and a 350-MW steam-turbine generator on a common shaft. The 9FA gas turbine features a reverse-flow, 18-chamber, dry, single-stage, dual-mode, low-NOx combustion system which can operate with either gaseous or liquid fuels. This type of unit generally has dual-fuel capability with distillate fuel as a backup to natural gas. The Black Point project in Hong Kong uses this basic design.
The shaftline of the combined-cycle unit is supported on an elevated, reinforced concrete foundation with the feedwater and steam piping routed within the foundation to the heat-recovery steam generator (HRSG). Each of the generating units have dedicated ancillary equipment located along the shaftline and around the HRSG.
Optimum output and efficiency of the combined-cycle power plants, when base-loaded, is achieved through a three-pressure reheat cycle. To facilitate a reheat cycle, a specific gas turbine exhaust temperature is chosen. Where combined-cycle projects operate with low load factors (or variable loads) and have low-fuel costs, GEC Alsthom believes that a lower-cost, two-pressure, non-reheat cycle may be justified.
Power plants with multiple-generating units operating at reduced loads have lower overall efficiencies. However, by reducing the number of units, a power plant`s overall efficiency can be increased. The disadvantage is it takes longer for the plant to pick up load.
Multiple, single-shaft units can be located in a common building with the control room and central administrative buildings constructed adjacent to the first unit. Although it is possible to have unlimited single-shaft units in one building, the space required for the cable connections to the central control room for more than six units would be excessive.
First supercritical power plant in China
On October 22, 1987, a contract was signed in the Great Hall of the People in Beijing, China, between Huaneng International Power Development Corporation of the People`s Republic of China and a consortium of foreign suppliers for the design and construction of the Shanghia Shidongkou Second Power Plant. The 1,200-MW plant has two 600-MW units–each with a supercritical, single-reheat, once-through, supercritical steam generator and a four-cylinder tandem steam generator.
ABB-Boiler Ltd. supplied the supercritical pressure steam generators, while ABB-CE was responsible for the steam generator auxiliary equipment–including the burners, soot blowers, pulverizers and the steam-generator steel structure. The steam-turbine generators, the condensing and feedwater heating systems, associated auxiliary equipment, and the instrument and control systems were supplied by ABB Power Generation Ltd. Sargent & Lundy, Chicago, USA, was the architect-engineer and the consortium`s leader.
The plant has been constructed on the south shore of the mouth of the Yangtze River in the province of Shanghia. Approximately 27 km northwest of the city of Shanghai. Unit 1 has been in commercial operation since June of 1992 and Unit 2 since December 1992. Because of the need for electric power in the Shanghia area, the contract required that the first unit be completed and in full load operation within 38 months of signing the contract. The second unit had to be in commercial operation eight months later.
ABB Power Generation Ltd. designed the plant for a variety of operating modes–including base load, cycling between 35 percent and 100 percent load, and two-shift operation. When operated on a two-shift basis, the plant is shut down at night and restarted hot the next morning. During the day the unit is run at full load. Shidongkou Second Power Plant has a 100 percent high-pressure bypass system and a 65 percent low-pressure bypass system.
Shidongkou plant details
Bituminous coal, supplied from mines in the Shanxi province of China, is shipped by rail to the Port of Qin Huang Dao, a distance of approximately 900 km. From Qin Huang Dao the coal is shipped 600 km by freighter to the plant where it is unloaded and transported via conveyors to the plant`s coal storage area. After being crushed the coal is distributed via conveyors to storage silos. Each unit has a separate storage silo, six coal pulverizers and storage capacity for up to 10 hours of unit operation at full load.
Because the Shidongkou power plant uses supercritical steam generators, the plant is able to save up to 90,000 tons of coal per year. According to ABB Power Generation, the plant has a specific coal consumption of 374 g/kWhr, which is about 15 percent below the average of other Chinese power plants. Figure 4 compares coal consumption for supercritical vs. subcritical units.
The steam flow of the boiler at maximum continuous rating (MCR) matches the steam-flow requirements of the steam turbine at MCR, plus an additional margin. When operating on coal, the steam generators (boilers) are capable of part-load operation down to 30 percent MCR. Below 30 percent MCR, heavy oil is used to support and stabilize combustion. Light oil is used for ignition and startup.
Each of the steam generators has two forced-draft fans, two induced-draft fans, two primary air fans, two air preheaters and two independent ash-removal systems. The bottom ash system removes the ash and slag from the collection hoppers at the bottom of the boilers, and also the pyrites. A pneumatically operated flyash system transports the flyash from the precipitator and airheater hoppers to flyash silos.
In order to restart the steam turbine and to maintain stable steam-generator operation immediately following a partial or total loss of load, the units are fitted with two-stage bypass systems. The bypass system also enables the steam and metal temperatures to be matched during startup of the unit. As a result, startup times are reduced. During an uncontrolled turbine trip, the bypass system prevents a master fuel trip.
The need for more capacity
When put into commercial operation in 1992, the Shidongkow Second Power Plant (Figure 5) was the most efficient and modern coal-fired power plant in China. As a result, it is making more efficient use of the country`s vast coal resources. Today, Asia is looking at adding thousands of MW of new capacity during the next 10 years to keep up with economic growth. China alone is looking at adding more than 150,000 MW of new capacity. However, as I mentioned at the beginning of this article, the big question is: “Who will finance all of the new projects?”
Figure 5. 1,200-MW Shanghai Shidongkou supercritical power plant (right), P.R. China. Source: ABB Power Generation, Ltd., Switzerland.