Study on Economic Partnership Projects. in Developing Countries in FY kV Lines in West Java, in Indonesia SUMMARY.

Transcription

1 Study on Economic Partnership Projects in Developing Countries in FY2007 Study on Upgrading Transmission Capacity of Existing 500kV Lines in West Java, in Indonesia SUMMARY March 2008 Tokyo Electric Power Services Co., Ltd. Mitsubishi Corporation

2 Chapter 1 Summary 1.1 Needs and background of the project In 2006, the electricity demand of Indonesia Java and Bali Island was 15,954 MW which is about 1/12 of the electricity demand in Japan. Almost 60% of the electricity demand in Indonesia, if Java is divided into three areas between western, central, and eastern part, exists in western Java where Jakarta is located. On the other hand, the installed capacity of West Java is about 48% of the total capacity in Java- Bali. Currently West Java region is short of power supplies and depends on such insufficiency of the electric power supply from other areas, especially from eastern part Java. Currently, large volume of electricity has been transmitted over 800km from eastern part of Java to Jakarta and has forced the network system to carry an enormous power, which has been a problem. In order to solve this situation, transmission line reinforcement is required. However, since the new transmission line construction in overpopulated area is much difficult and cannot expect completion as scheduled. By examining the current situation, the philosophy of electric power development was changed into promoting the power supply sources near the demanded areas. The electricity demand forecast shows 6.5% increase per year and by the year 2016 the demand will increase to 30,080MW, which is 1.9 times more than the current electricity demand. Considering such forecast, approximately 80% of the planned power plant development up to 2016 amounting to 18,176MW will be constructed in western Java area. Moreover, power development plan up to 2011 from Jakarta and to the west is expected to increase capacity by 2,400MW. Currently existing transmission lines in the West Java area consist of 110km of 500kV 2 circuits from Suralaya Power Plant to Gandul Substation, near Jakarta area and 1 circuit of 500kV transmission line from Suralaya Power Plant to Cibinong Substation via Cilegon Substation. Since Suralaya - Gandul Line has been constructed in the early stage of 1983, the transmission capacity is 1,980A (1,628MW), which is not sufficient to transmit the power from the developing new power plant, therefore overload is expected in near future. In conclusion an increase in the transmitting capacity will be required. According to the Long Term Development Plan 2007(RUTPL 2007) issued by PT. PLN(Persero), power flow in Suralaya - Gandul Line is mentioned to be 2,500MW and as long as the 2 circuits are under operation overload will not occur. However, under contingency condition due to fault occurrence etc., power flow in the remaining circuit will exceed the capacity which will cause the transmission line to overload. Since the facilities configuring bulk power network system such as 500kV lines should not be overloaded even under contingency condition of one unit of other facilities to supply electricity stably and avoid black out. Considering such philosophy, Suralaya - Gandul Line needs reinforcement up-rating of the transmission line system.

3 In addition, during the first Feasibility Study Team s visit to Jakarta, PT. PLN (Persero) requested the Team to also conduct the feasibility study on the 500kV transmission line between Cibinong Substation and Muara Tawar Power Plant via Bekasi Substation and Cawang Substation since the line is expected to be overload in near future. As the Team investigated the future plan, the Team found out that PT. PLN plans to shutdown the aged Tanjung Priok Oil Firing Power Plant after development of coal firing power plants. Considering such situation, the Team decided to conduct the additional feasibility study on the 38km transmission line between Cibinong Substation to Bekasi Substation (transmitting capacity : 1980A(1628MW)). 1.2 Basic policy to determine the project As a countermeasure against a transmission line overload by new power plant development in a western Java area, PLN included the plan to develop a new 500kV 1 circuit between Suralaya and Gandul in Long Term Development Plan However, due to increasing opposition movement and a large amount of compensation on land cost, construction of a new transmission line has been facing difficulties. For this reason, the plan to develop 1 circuit between Suralaya - Gandul Line has been deleted in the Long Term Development Plan 2007, due to the expected difficulty of construction near Gandul Substation which is located in the overpopulated area in Jakarta suburbs. As for Cibinong - Bekasi Line, which is located in Jakarta suburbs, the construction of a new transmission line is also impossible, therefore countermeasures other than the construction of new transmission line to increase capacity is inevitable. Under this situation, PLN shows their interest for the countermeasures against overload by utilizing the existing transmission line. Since the most difficult content which is the land acquisition being unnecessary for this Project, there are merits (ex. the possibility of delay for the construction can be minimized and construction cost to be less) to up-rate the transmission line. 1.3 Outline of the Project In order to up-rate the transmission line capacity it is usual to build a new overhead transmission line using the existing transmission line route. However, there is a technology developed in Japan to double the capacity of electricity current while securing the ground clearance of existing transmission line, by just re-conductoring the existing conductor. By utilizing this technology, increase in capacity of the existing 500kV Suralaya - Gandul and Cibinong - Bekasi transmission line will be achieved. As for the use of up-rating conductors, this feasibility study had been studied under the premise of utilizing either the Concentric-lay-stranded super thermal resistant aluminum alloy conductors, aluminum-clad invar reinforced which has many track records all over the world or Concentric-lay-stranded gap type thermal resistant

4 aluminum alloy conductors, steel reinforced Required transmitting capacity There are 3 circuits which transmits electricity from Suralaya Power Plant to Jakarta including North Line with 2 circuits from Suralaya Power Plant to Gandul Substation (transmitting capacity per circuit of 1628 MW) and South Line with 1 circuit from Suralaya Power Plant to Cibinong Substation via Cilegon Substation (transmitting capacity of 2033 MW). Since electric current will flow in accordance with the Ohm s Law, once the North Line s capacity is excessive, South Line will overload. In this sense, it is important to keep the balance between North Line and South Line. In case, Suralaya - Gandul Line s transmitting capacity per 1 circuit is equaled to 3,246MW, both North and South Line s transmitting capacity will be balanced. This is 1.99 times the existing transmission line capacity of 1,628MW, is nearly equal to the technical limit of up-rating conductors. In conclusion required transmission capacity and technical limit will be also balanced. Since the route of existing Cibinong - Bekasi line is most important to the Jakarta suburbs, the required transmitting capacity in this study has determined 3,246MW under the technical limit, which is the same figure of Suralaya - Gandul line Network operation during the re-conductoring work The construction period for re-conductoring 110km Suralaya - Gandul line is expected to take one and half years. The re-conductoring work is carried out under no operation condition, which will force the other lines to overload. Therefore during the construction, output of Suralaya Power Plant shall be decreased by 1,200MW to avoid such overload. As the output of the power plan decrease it will have great influence to the supply-demand balance, construction work is considered to start from 2010 when a new power plant is expected to start commercial operation and the tight condition between supply and demand will be mitigated temporally. Even if a fault occurs during the construction period the network must still be able to operate stably. As a result of stability analysis under the conditions of output decrease of the Suralaya plant by 1200 MW stable operation is achievable. Re-conductoring of a Cibinong - Bekasi line shall be carried out in 2012 after the end of reconductoring construction of a Suralaya - Gandul line in order to avoid duplication of construction from a viewpoint of construction power reservation. Although it is expected that the overload of other 500kV transmission lines will not occur during the re-conductoring work, in order to keep the safety of the construction works, 150kV transmission line running under the 500kV line will need to be out of operation. The way to avoid the overload of 150kV system shall be sufficiently considered.

5 1.3.3 Ground clearance and other clearances The ground clearance of the transmission line constructed more than 20 years ago, has been designed at 15.0m with enough margin satisfying the current regulation at 12.5m. In addition to the ground clearance, the clearance between the conductor and buildings or roads also fulfills the current Indonesia s clearance regulations. However, the crossing of the 70kV/150kV transmission lines are designed with less clearance compared with the current regulations. In this situation, since minimum clearance has been measured as approximately 8.0m and the current regulation regulates 8.5m; further study shall be carried out Selection of appropriate conductor (1) Types of conductor The current requirement for the power transmission capacity is twice (3,246 MW) the capacity of the existing transmission line, but even if twice as much capacity transmission line is established it is still necessary to satisfy the standard with the present ground clearance and clearance with other structures. Moreover, it is necessary to also satisfy standards for electricstatic field strength and electromagnetic field strength, corona noise, radio noise. The following two conductors are recommended which fulfill the above standards 1 Concentric-lay-stranded super thermal resistant aluminum alloy conductors, aluminumclad invar reinforced (ZTACIR) When the current in the conductor increases the temperature of the conductor will proportionally increase and therefore the conductor will be elongated. As the conductor elongates, the ground clearance of the conductor decreases and when the clearance is at the standard height, the transmission line capacity is decided. Therefore by controlling the elongation caused by the temperature change, transmission line capacity can be increased. For Invar type conductor by applying an invar wire with lower co-efficient of linear expansion property in the core wire portion, the elongation of the conductor can be restrained. 2 Concentric-lay-stranded gap type thermal resistant aluminum alloy conductors, steel reinforced (GTACSR) A usual conductor is composed by double structure of a steel wire and an aluminum wire, since both are closely stranded; by a rise of the temperature, the elongation of the conductor is determined by both of steel s and aluminum s behavior. By adopting a gap between the layer of the steel core wires and the layer of inner aluminum wires, the Gap type conductor has attained the purpose by controlling the elongation of only steel which is half of the aluminum. (2) Transmission loss Although up-rating conductor s cross sectional area and resistance are similar to existing

6 conductors, the up-rating conductor doubles the electricity current, and therefore transmission loss of the electricity for Gap conductor will be twice as much and for Invar type conductor 2.5times Method of re-conductoring Transmission Line (1) Construction method of candidate conductors An Invar type conductor can be re-conducted by means of the conventional paying out and sagging method which is the same as a conventional conductor. On the other hand, the paying out method is the same for Gap type conductor, but for sagging work, task which installs a tensionclamp so that the conductor s tension may not be applied on the aluminum wire is necessary. (2) Conventional tension stringing method (in the general location) This method is conducted by connecting the up-rating conductors to the existing conductors, and then by pulling out the existing conductors to replace to the up-rating conductors. To implement this method the construction workers will have to be cautious with the obstacles in the line crossings by setting up the sufficient scaffold on top of the obstacles to avoid contact with replaced conductors. But as a merit, this method can be paid out all 4 conductors simultaneously and therefore the time of construction will be minimized. (3) Cradle block stringing method (for urban housing area or important line crossing) For the urban housing area or important line crossing, the location to set up the scaffold will be very difficult to obtain. Therefore the construction will be conducted by means of so-called cradle block system method. The cradle block system is a method to distribute twin rollers in 20 to 30 meters intervals in the relevant span, to hang upper roller on the existing conductor and to replace the up-rating conductor by means of the roller installed underneath. By using this method, the sag of this conductor will be restrained by the existing conductors therefore even if there are urban housing area or important line crossing it is not necessary to set-up any scaffoldings to pay out the up-rating conductors. However for his method the construction speed will be slower since the each individual conductor can be re-conducted one by one. (4) Construction Period If the construction is conducted under conventional tension stringing method, paying out of 4 conductors can be simultaneously carried out which progress of about 8km/month per group / circuit is expectable. On the other hand, when a cradle block system is adopted, since this method needs to pay out conductor one by one, it will only progress about 4km/month / circuit can be expected. When the both methods are chosen half by half and by implementing two groups; the

7 construction period excluding a design and product manufacture is estimated at for Suralaya - Gandul line is about 16 months and for Cibinong - Bekasi line is about 4 months Total Project Cost The components used to calculate the total Project cost is constructed by the construction cost of transmission line, construction cost of substation, engineering cost, administration cost. The components of the Project cost were calculated using past similar projects and the result is as shown in table 1-1. Table 1-1 Total Project Cost Unit:US$ Mil Component Cost Construction cost of transmission line 83.0 Construction cost of substation 24.0 Consulting cost 5.4 Administration cost 10.7 Total The following items are not included in total Project cost. EIA implementation cost Public official approval cost and license acquisition cost Tax Escalation Content and result of Economical Evaluation The alternative plan method was applied to make economical evaluation of this Project. As an alternative plan for this Project, to establish a new transmission line with similar transmitting capacity was used. As referred in Table 1-2 EIRR was 12.72% (over 10% of the average judging standard of the discount rate (opportunity cost of capital) in developing countries, determined by the World Bank and the Asian Development Bank) and B/C also was (more than 1.0),and as a result this project has high potential. Moreover, when benefit decreases 5% and expense increases 5%, by conducting a sensitivity analysis EIRR becomes 8.34% and 8.53%, respectively, and it can be said also in these cases that this project has sufficient economic benefits.

8 Table 1-2 EIRR Result EIRR (%) B/C Ratio B-C (Thousand $) , Content and result of Financial Evaluation The calculation for the index of financial return is calculated by using FIRR (Financial Internal Rate of Return) which resulted at 12.6% (greater than Japanese Soft Loan interest) and the Benefit Cost Ratio which resulted to (greater than 1) shows that the financial return is sufficient. In addition, the sensitivity analysis which was calculated by increasing the financial expense by 10% and decreasing the financial benefit by 10%, as a result the FIRR still surpassed 10% at 10.4% therefore this Project return will still make sufficient profit A comparison result and the reason for optimal proposal selection with alternatives In Indonesia, the overload of existing transmission lines is expected by the great number of power plant development from Jakarta and to the west, and for a stable supply of electric power, the increase in transmitting capacity is an important issue. There are two methods to increase transmitting capacity, establishment of a new transmission line and up-rating an existing transmission line, the latter has the following merits. 1 A comprehensive cost of construction is low. 2 The land acquisition which is a major factor of completion delay is unnecessary, and completion as scheduled can be expected. 3 Since the number of transmission line routes does not increase, the impact to environment is small Environment and social impact Since this Project only consists of up-rating the conductor using the existing transmission lines, compared with constructing new transmission lines, there are no need to obtain new land and the necessity for the removal of residence. Since the current of the transmission line increases, electromagnetic field strength will also increase to 53.1μT. This value is still well under regulation value of 100μT. On the other hand, the electrostatic field strength is same as the existing conductor Dove (5.5kV/m), and is slightly larger than the regulation value 5kV/m. However if the conductor s ground clearance is raised 1m, the electrostatic field strength will be less than the regulation value at 4.9kV/m. Actual ground clearances have enough margin in most sections, and it is possible to take some countermeasures at section where the clearance is severe. Therefore the environment and social impact are very small.

9 1.4 Project implementation schedule By taking past experience using Japanese Soft Loan, the following represents the Project schedule from the date Japanese Soft Loan Agreement is concluded to the date of which this Project will start operation. Pre-Construction Period Selecting and Appointing the Consultant Field Study EPC Specification Preparation Bid Document Preparation Evaluate Bid Document EPC Contractor Appointment Total(Construction overlap is taken into account) Construction Period Suralaya - Gandul Re-Conductoring Work Cibinong - Bekasi Re-Conductoring Work Substation Construction Total(Construction overlap is taken into account) 12 months 8.5 months 8.5 months 4.5 months 28 months 26 months 13 months 27 months 31 months Gland Total 59 months 1.5 Feasibility of request and implementation of Japanese Soft Loan To strengthen the electricity supply capability of West Java Transmission Line System is an urgent issue in Indonesia. Currently the government of Indonesia is moving forward with a program called the Crash Program which is to plan to create 10,000MW of Coal-fired power plant by the year Since there is an increase in capacity of the power plant, the need for increase in capacity of the transmission system is very high. Therefore there are high potential for this Project to receive a request from Indonesia for Japanese Soft Loan. 1.6 Technical advantage of Japanese companies The major products proposed for this project, the up-rating conductor which can increase the transmission line carrying capacity to double comparing with the existing ACSR keeping the existing ground clearance, was invented and developed in Japan where the utilization of the land for the transmission line is difficult but the density of electrical demand is quite high. The relevant products studied for their application in this project are - Concentric-lay-stranded super thermal resistant aluminum alloy conductors, aluminum-clad invar reinforced

10 - Concentric-lay-stranded gap type thermal resistant aluminum alloy conductors, steel reinforced which are developed by the Japanese technology in 1982 and 1971 respectively. In addition, the (super) thermal resistant aluminum alloy materials, which were also developed in Japan and have been widely used since 1970s, are specified in IEC as an international standard drafted by the Japanese committee and established in February Invar type of conductor is now produced in Japan, Korea and Austria, but the raw material for the invar wire is supplied by a Japanese company. Gap type conductor is now manufactured only in Japan. 1.7 A concrete schedule and a risk of obstructing realization The pledge of the first Japanese Soft Loan to Indonesia was carried out in 1968, and since then the Japanese Soft Loan has accumulated to amount 4,130 billion yen. In order to request the Japanese Soft Loan, there is the need to obtain acceptance from PT. PLN (Indonesia Electricity Company) and Bappenas (National Planning and Development Agency). In this situation that there is no risk of the Indonesia country in the use of the Japanese Soft Loan since the timely repayment schedule which Indonesia has conducted in the past. The following refers to the schedule up to this Project to be realized. 2008/1/31 Completion of the F/S Report 2008/10 Request for this Project to be on the Blue Book to Bappenas 2009/4~6 JBIC Contact Mission 2009/7 Japan/Indonesia Government Pre-Meeting 2009/12 Request to the Japanese Government for Japanese Soft Loan 2010/2~3 Japanese Soft Loan procedures, E/N, Japanese Soft Loan L/A 1.8 Project implementation map of Indonesia This 500kV Project is implemented from Suralaya Power Plant located in the State of Banten in the West Java Area to Gandul Substation located in the State of West Java for the distance of 110km and Cibinong Substation located in the State in West Java to Bekasi Substation which is also located in the State of West Java for the distance of 38km. Please refer to the Fig. 1-1 for the areas for Project implementation in reference to Jakarta.

11 Suralaya S/S BojonegaraP/S (planned in 2014) Remarks :500kV Suralaya-Gandul Line (1circuit 2routes) :500kV Cibinong-Bekasi Line (1circuit ) :express way :railway P/S:Power Station S/S:Substation JJaakkaarrt taa (Ceennt ( teerr) ) Bekasi S/S 1-10 Balaraja S/S (planned in 2009) Gandul S/S Cibinong S/S km Section 1 Summary Fig. 1-1 Project implementation map