Air Power Plant (PLTA) Batang Sinamar developed by PT. Insan Mutiara Energi, located in Nagari Lubuk Jantan, Lintau Buo Utara District, Tanah Datar Regency, West Sumatra Province with an installed capacity of 20.5 MW. Energy production is sold at 95.87 GWh per year. The land needed for development is ± 49,275 Ha. The time needed for development is needed for 36 months and the construction time is 24 months, with construction costs of Rp. 481,839,000,000 ($ 37,064,538 dollars). The assumption of the source of the loan is 70%, the source of the funds is 30%, the interest rate on the bank loan is 14%, the BCR value is 1.06, the IRR is 14.25% while the NPV is Rp. 324,031,448,171 ($ 1,189,888 dollars) and this project will Break Event Points (BEP) in the eighth year.
A. Technical Aspects
Technical aspects include study:
Conduct hydrological analysis through watershed data (DAS), Automatic Water Level Recorder (AWLR) and rainfall around the location to determine the planned discharge for the plant and flood discharge plans for planning civilian buildings in the river channel.
Conducting topographic survey and measurement activities to obtain conditions and situations as well as height differences from a location that will produce a situation map, long section and cross section.
c. Geology: Conduct geological studies to get an overview of the geological conditions of the study area by guiding geological maps, earthquake maps and conducting soil structure checks.
d. Making basic layouts and designs.
B. Machine and Equipment Aspects
Based on the review of technical aspects, the machinery and equipment used will be examined, starting from the machinery and equipment in the Power House to the point of transaction agreed with PT PLN (Persero), including the pole and distribution network, so that the energy produced connected optimally.
C. Environmental Aspects
Environmental aspects include:
a. Identifying field conditions both from the designation of the area / regional status as well as Economic, Social and Cultural.
b. Identifying impacts that will arise both during pre-construction, construction and post-construction (operational).
D. Financial Aspects
Financial aspects include:
a. Make a calculation of estimated investment value needed from pre-construction activities, construction to the Commercial Operating Date (COD).
b. Make calculations of estimated operational costs and estimated cash flows.
c. Make financial analysis of several investment criteria including: Internal Rate of Return (IRR) project, IRR equity, payback period, Net Present Value (NPV), cost of goods manufactured, selling price of electrical energy, Benefit Cost Ratio (BCR) and ratio- other relevant financial ratios.
Geographically the Tanah Datar district is in the position of 00 ° 17 "LS - 00 ° 39" LS and 100 ° 19 'BT - 100 ° 51 BT, with an area of 1,336 km² or 133,600 Ha which has borders with several districts / cities in Sumatra West, namely:
- North: Agam Regency and Lima Puluh Kota Regency
- Southern side: Sawahlunto City and Solok Regency
- West side: Kabupaten Padang Pariaman
- East side: Sijunjung Regency
The planned development of the Batang Sinamar hydropower plant is in the Batang Sinamar River Flow. Based on the studies that have been carried out, civil building facilities are planned on the right and left sides of the river.
Location Area PLTA
Tanah Datar Regency is an area with topographic conditions ranging from flat, undulating to hilly with elevations ranging from 200-1500 m above sea level. Tanah Datar Regency is located in a mountain basin and hills with a height ranging from 100 - 2,891 m above sea level.
The current landscape forms are a reflection of the natural processes that work in the Tanah Datar district area, where the landscape formation process is strongly influenced by the types of rocks, geological structures and process intensity (erosion).
Based on the slope of the land, Tanah Datar regency is grouped into 6 parts, namely:
a) Regions with land slopes of 0 - 3% (Datar) are mostly distributed in Tanjung Emas, Rambat, Lintau Buo, Tanjung Baru sub-districts and Padang Ganting Districts.
b) Areas with slope of 3 - 8% (Slightly Sloping)
most of them are scattered in Lima Kaum, Rambat, Tarab, Salimpaung and Sungayang Districts.
c) Areas with a slope of 8-15% (Corrugated),
mostly spread in Lintau Buo Utara District, Pariangan, Tarab River, X Koto and Batipuh District.
d) Areas with land slopes of 15-25% (Somewhat steep), spread almost in the same sub-district, except the central part of Tanah Datar district area includes; north of Lima Kaum sub-district, Tanjung Emas sub-district and Rambat sub-district, south of Lintau Buo Utara sub-district, Sungayang district, Pariangan sub-district and Sungai Tarab sub-district.
e) Land with a slope of 15-25% is the most extensive and dominant area in Tanah Datar district.
f) Regions with land slopes of 25 - 45% (Steep), mostly spread in X Koto, South Batipuh, Sungayang and Tanjung Emas sub-districts.
g) Areas with a slope of> 45% (Very Steep), mostly spread in the west, north and the eastern part of Tanah Datar. The slope component above 45% makes it difficult to develop the area in Tanah Datar Regency because the area with very steep slopes is potentially threatened by landslides and erosion.
Illustration of changes in energy in a PLTM
In general, electricity-powered power plants are called Minihydro Power Plants (PLTM). The working principle of the PLTM by converting the potential energy of water into mechanical energy on the turbine shaft. Mechanical energy in the form of a spin on a turbine coupled with a generator will produce electrical energy.
Type of Swelling Based on Installed Capacity
The process of changing energy (energy conversion) from the potential energy of water to electrical energy through several stages of the process, starting from the water source (weir) to the power house which is the main building where electrical mechanical equipment is a PLTM. to the burden in this case the connection point of electrical energy transactions with PT. PLN (Persero).
Ilustrasi Sistem Pembangkit Listrik Tenaga Minihidro (PLTM)
Illustration of energy conversion from a PLTM as shown in 3.2. The river flow with a certain height difference in the upstream section is constructed of weirs and intakes. Then the water is channeled to the power house (PH) through the water way and sediment trap. Before arriving at the PH, the water flow is first calmed in the head pond. Furthermore, from the sedimentary bath, the pipeline is distributed rapidly (pen stock) to PH to enter the turbine. After experiencing the energy conversion process in the turbine, the water flowed back to the river through the tail channel. The generator that is coupled with a turbine will emit electrical energy proportional to the potential energy of the existing water. Then the voltage coming out of the generator is raised with the transformer to get the same voltage as the distribution voltage of PT. PLN (Persero). From the transformer the electrical energy is then channeled through the distribution network to the substation (GH) as the point of transaction.