Annexure 11 - I-maritime Techno-Eco Feasibility Report

8/9/2019 Annexure 11 - I-maritime Techno-Eco Feasibility Report

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Maharashtra State Power Generation Co. Ltd

Maharashtra State Power Generation Co. Ltd

Techno-Economic Feasibility Report

For Imported Coal Based Thermal

Power Station at Dhopawe(Executive Summary)

Prepared By

i-maritime Consultancy Private Limited

Techno-Economic Feasibility Report - Dhopawe

206, Hermes Atrium Tel : +91-22-2757 9611Sector 11, CBD Belapur, Fax : +91-22-2757 9612Navi Mumbai E-mail : [email protected] Website: www.imaritime.com

i-maritime Consulting 1


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Maharashtra State Power Generation Co. Ltd Techno-Economic Feasibility Report - Dhopawe



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1. Executive Summary

1.1 Introduction

Maharashtra State Power Generation Company Limited (Mahagenco) was formed by separating thedistribution and generation functions of Maharashtra State Electricity Board (MSEB) into two companies,namely MSEDC Ltd. for distribution and Mahagenco for generation.

1.2 Project Background

Mahagenco envisages setting up an imported coal based thermal power plant of capacity 2 x 800 MW atDhopawe, District Ratnagiri. Mahagenco has awarded i-maritime Consultancy Private Limited (i-maritime)the assignment of preparing the Techno Economic Feasibility Report for the coal import facility.imaritime consultancy is India's leading business consulting firm in the maritime sector.

1.3 Data sources and References

Following charts and reports have been referred in the appreciation of the site

Hydrographic chart 2011- Port Dabhol of scale 1:25000 (Reference 1)

TEF Report for the development of Anjanvel port by CES, 1996 (Reference 2)

Hydrographic Survey data along river Vashishti, chart No-654/2003, MaharashtraMaritime Board of scale 1:10000 (Reference 3)

1.4 Location of power plant site

The coordinates of the proposed power plant are as follows:

Table 1-1 Proposed power plant - site coordinatesCoordinates of site for proposed power plant

Point Latitude Longitude

A 170 34' 06"N 73 0 11' 15" E

B 17 0 33' 48" N 73 0 10' 48" E

C 170 32' 45" N 73 0 10' 48" E

D 17 0 32' 30" N 73 0 12' 12" EE 17 0 32' 30" N 73 0 12' 06" E

F 17 0 33' 09" N 73 0 12' 12" EG 17 0 33' 48" N 73 0 11' 24" E

1.5 Site characteristicsThe entrance to the Vashisti River is bound by hills to the south and north. At the entrance to the river, asandbar of 750-850m widths has been formed from gradual accretion, with depths from -3.0m to -1.5m. The10 m contour in the open sea is approximately 3.0 km from the mouth of the river.



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1.5.1. Wind

Based on the field observations carried out by the National Institute of Oceanography, Goa in 1994,non monsoon wind onshore could reach maximum up to 11.0 m/s with extreme speed of 16.0 m/s.During monsoon, offshore wind reaches up to 18.0m/s.

The predominant wind direction is from N-NW to S-SE during fair season and from W-NW to E-SE duringmonsoon. Wind rose diagram reproduced from reference 2 is shown in drw.no 2. Wind records forcyclonic conditions are not available for analysis. However, it is anticipated that significantly higher windspeed would be prevailing during cyclonic conditions.

1.5.2. Tides

Tidal data for Vashishti River as obtained from reference 1, Hydrographic chart no 2011 published byNaval Hydrographic office, Dehradun (Vashishti River) is shown in Table 1-2.

Table 1-2 Tidal Variation - Naval Hydrographic OfficeParticulars Naval Hydrographic OfficeMean High Water Spring + 2.74 m CD

Mean High Water Neap + 2.19 m CDMean High Low Water Spring + 1.16 m CDMean Low Water Neap + 0.61 m CDMean Sea Level + 1.70 m CD

1.5.3. Waves

Past study of Central Water and Power Research Station, Pune (CWPRS) indicates that:

Direction of waves are from W-SW to E-NEWaves exceeding 2.0 m occur frequentlyWave height of about 4.0 m with period ranging 12 to 14 sec is reported to be occurring duringmonsoon

As these readings have been taken in the quadrant lat 15 0 48 N to 20 0 48 N and long 60 0 0 73 0 0 N,fresh readings need to be taken at the site.

The significant wave height permissible at the jetty for large vessels is about 1m and permissible waveperiod is less than 10 sec. This phenomenon could not be studied due to non-availability of waverecordings at the proposed site. This needs be done during the Hydrographic survey.

1.5.4. Currents

In the river, the current at peak flow and at ebb is reported to be of the order of 2.0m/s. At the river mouth,this is reported to be of the order of 0.75 m/s to 0.85 m/s at the maximum as per Reference 2 cited above.On open seacoast, the currents are reported to be 0.55 m/s to 0.65 m/s flowing in the N-S direction.

This phenomenon needs to be carefully studied to ensure safe berthing operation. This is because ingeneral the maximum current should not exceed 4 knots (2m/s) where possible. Where the currentvelocity exceeds this value, it may be necessary to adjust the channel cross section to maintain anoptimum flow.



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1.5.5. Soil

Previous study at the sand bar located near the entrance to the Vashishti River indicates there is no rockdown to -10m depth (source: Reference 2). Further investigations may be carried out at the sand bar,approach channel and the jetty site before undertaking dredging and detailed design of civil works.

1.5.6. Littoral Transport

The general direction of drift is from N-S @ 0.2 million cu. m. per year (source: Reference 2). As per thestudy carried out by MMB, the sand bar formation at the river mouth has been found to be have formedover the period of last 100 years.

CWPRS study estimates moderate filling about 1.0m-1.5m in the river channel over a year if dredging isresorted to. This quantum will vary according to depth of dredging and therefore needs to be investigatedduring Detailed Project Report (DPR) preparation.

1.6 Functional requirements

1.6.1. Approach Channel

For handling a panamax vessel, with one-way movement, and considering the site characteristics, anapproach channel of width 250m and dredged up to -15.5m is required. The semi-restricted channelneeds to be provided from the 15 m contour, which is approximately 5 km from the mouth of the river.

1.6.2. Turning circle

The turning circle shall be located where the river width is about 1.5 times the width of the turning circle. Tohandle panamax class vessels, a minimum diameter of 460m is required. The depth of the turning circlehas to be 1.2 times the maximum draft of the vessel, which is -15.5m.

1.6.3. Dredging

Capital dredging is a requirement for the proposed berthing facility .The capital dredging for various sitesare as follows.

Table 1-3 Capital dredging in million cu.m

Anjanvel Bay Veldur Bay Dhopawe BayCapesize 25.33 29.08 30.88Panamax 19.08 21.33 22.41Lighterage 0.20 0.20 0.20

1.7 Berthing facility

1.7.1. Direct berthing

The berthing facility suggested consists of a jetty of length 270m x 28.7m wide for panamax vessels. Fourrows of 1200 mm diameter concrete cast in-situ piles are provided. The area alongside the jetty is to bekept dredged to -15.0m depths to provide safe berthing of design vessel. The alignment of the jetty willhave to be such that it would minimize effects of current, wind and wave on the berthing vessel, for whichfurther investigation is recommended. These investigations need to be taken up in the DPR stage.



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1.7.2. Barge unloading

The berthing facility suggested consists of a jetty of length 200m x 23m wide. Four rows of 1200 mmdiameter concrete cast in-situ piles are provided. The area alongside the jetty is to be kept dredged to 5mdepths to provide safe berthing. The alignment of the jetty will have to be such that it would minimize effectsof current, wind and wave on the berthing vessel, for which further investigation is recommended. These

investigations need to be taken up in the DPR stage.

1.7.3. Approach Jetty

The main jetty is likely to be sited where depths are naturally available. To connect the main jetty to theland a 13.5m wide approach trestle has been provided. Four rows of 1000mm diameter vertical piles willsupport this approach trestle. A roadway of width 4.5m has been provided.

1.8 Coal import facility

Based on the above site features, shipping trends, economics of logistics cost and envisaged throughputrequirements, possibilities for development of port facilities are evaluated with regard to the two options oflighterage and direct berthing respectively. It may be noted that this is based on existing available dataand analysis of pertinent site conditions.

1.8.1. Option I - Lighterage operations with barges

This essentially involves double handling of cargo. Imported coal is transported by vessels of panamaxand capesize category to unloading port. The unloading of cargo from the mother vessel is done at thenatural deep-water anchorage by ships own gear. Further unloading of coal from barges would be carriedout at the barge berth located inside the river.

1.8.2. Option II - Direct berthing facilities

This would entail creating berthing structures and navigation channels with mechanized coal unloadingequipments compatible with the throughput requirement of 5.0 million tones per annum (MTPA) initiallyand going up to 10 million tones per annum (MTPA) eventually. Coal is generally imported from Australia,Indonesia, China and South Africa. Based on the current project site, Dhopawe would aim to handlepanamax/cape vessels.

1.9 Evaluating the options

The possibilities for development of marine facilities are evaluated with regard to the two options of directberthing and lighterage based on the following Techno-Economic parameters:

Functional requirementsOperating costCapital costNet present value of Capital Cost and Operating CostOperating EnvironmentOperational ease and efficiencyDowntime factorNautical and Navigational featuresDredging and siltationTerminal capacity



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Three sites have been examined and identified for direct berthing, namely, Anjanvel Bay, Veldur Bay andDhopawe Bay. Two design vessel sizes; panamax and capesize have been considered for importing coal.

The economic parameters are critical, more so when large investment outlay is planned. Therefore, the twooptions are compared on the Net Present Value (NPV) of the Capital Cost and Operating Cost.

Summary of NPV of Capital Cost and Operating Cost at Anjanvel Bay, Veldur Bay and Dhopawe

Table 1-4 Summary of NPV of Capital Cost and Operating Cost Bay (Rs. crore)

Location Panamax Capesize LighterageAnjanvel 2320 2294 2493Veldur 2354 2365 2472Dhopawe 2383 2411 2476

It is suggested that direct berthing option has advantages in the operational and financial aspects. It isclear from the calculations that the panamax vessel based functional requirements and facilities arepreferable to the capesize vessels based facility in view of the relatively huge amount of dredginginvolved in the latter option.

Lighterage option is not the optimal solution based on the operational efficiency and financial viability as ithas the highest financial cost among the options.

1.10 Evaluating development potential of the options

1.10.1. Option I (Lighterage)

Mid-stream operations of handling coal at anchorage are considered less suitable for the proposedvolumes. Cargo has to be handled twice in this option. This double handling of cargo has numerousdisadvantages. Berthing of barges alongside ship and changing of barges involves additional time factor.Besides, handling mid-stream involves cargo pilferage and wastage from some of the coal falling into thewater. The achievable rate of handling is limited and dependant on the on-board crane capacity. Care has tobe taken while chartering the vessels with ship cranes. Therefore based of various factors, the overallefficiency of cargo handling is reduced.

Barge movements from ship to riverside berthing facilities during pre-monsoon to monsoon season wouldpresent navigational difficulties and hence would contribute to downtime. The nautical and navigationalconditions are not considered to be the optimal for efficient lighterage operations.

Lighterage operations with double handling of cargo have inherent limitation. In lighterage option, tosatisfy 5MTPA requirement of coal a minimum of 3 panamax ships have to be working simultaneously atthe anchorages. This increases the number of barges required, the number of barge unloading berths,the coal storage area and the cargo handling equipment. This option does not therefore present theadvantage of capital cost efficiency.

1.10.2. Option II (Direct berthing)

Direct berthing facilities requires tranquil condition. The berthing facility in this option would be locatedalong the banks of the river at Anjanvel Bay, Veldur Bay or at Dhopawe Bay. These berths would bemade accessible by approach channel dredged to satisfy functional requirements.

These locations are protected to varying degree from the wave influence. Shallow water depths at theriver delta could limit the wave penetration effect inside the river. The operation environment is expected



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to allow cargo handling for ten months. Disturbance due to monsoon is expected to be severe for about 2months (June-July).

Direct berthing facility is expected to provide safe mooring of ships and tranquil conditions for unloading.Installation of the rated equipments will meet the desired throughput requirements. This system canaccept future enhancement of capacity and does not entail pilferages.

Operating environment is therefore conducive to cargo operations. Direct berthing allows definite planningand deployment of mechanized equipment. It would therefore be possible to create requisite capacity withflexibility for future enhancement.

Available depths in the river channel are in the range of average 9.0 to 12.0m.Occasionally, higher depthsare also noticed. Substantial dredging is involved to meet the functional requirements of direct berthing.

The location is a delta area of the river. There are possibilities of silt discharge in the location. Therefore,maintaining depths of dredged channel could be difficult. Excessive siltation of dredged channel mayconsequently require high level of maintenance dredging. This phenomenon needs to be carefully studied bymathematical modeling.

1.10.3. ConclusionBased on the above evaluation, it is seen that the direct berthing facility (option II) seems to be a betteroption from technical, financial and operational perspective.

1.11 Berthing facility Location

The riverfront was carefully studied and examined. Certain locations have been identified as potentialsites where the berthing facility could be located. These are shown in drw.no 6 and are identified as

Anjanvel BayVeldur BayDhopawe Bay

All the above three locations seem to be suitable for creating the desired facilities.

1.11.1. Anjanvel Bay

Anjanvel bay is the site closest to the river mouth. Contour of 10m is available immediately at the edge ofthe bay, which offers the advantage of deeper waters compared to Veldur bay and Dhopawe Bay. Therelative dredging costs are lower. However the berth tranquility conditions will need to be studied in detail, asthis site is less protected vis--vis Veldur bay. Anjanvel is the preferred option on account of thedeeper waters, subject to availability of the requisite tranquility conditions.

1.11.2. Veldur Bay

Veldur bay is the second possible site for berthing facility. This site offers 5m contours at the edge of thebay and provides relatively more sheltered waters. Veldur bay is used extensively by fishing craft and is inclose proximity to the passenger jetty. Under these conditions it could be difficult to establish berthingfacility without disturbing the existing system.

1.11.3. Dhopawe Bay

In view of the shallow depths, this site is likely to involve large amount of dredging. This location offers themost tranquil condition. The conveyor length in this option is the least compared to other options. Berthingfacility at this site would need to co-exist with the existing system, namely the cross-river ferries.



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1.11.4. Conclusion

With the available knowledge at this stage and the financial estimations, the sites of Anjanvel Bay, VeldurBay and Dhopawe Bay appear feasible. It is felt that provided the annual sediment transport is 0.2MTPA,numerical study results are encouraging and the river siltation is under desired limits, Anjanvel Bay andDhopawe Bay are preferable sites for the berthing facility. Further detailed investigations, as suggested

needs to be carried out to determine which one is superior vis--vis the other.

1.12 Conceptual Marine Facility

Various components of the proposed functional plan and layout have been developed from the followingproject parameters:

Minimum throughput requirement of 5 MTPA in phase IDirect berthing facility for panamax vesselsFully mechanized cargo handling facilityFlexibility for future capacity building of 10 MTPA in phase II

1.12.1. Design VesselFor the purpose of planning following vessel characteristics have been adopted

Table 1-5 Design vessel sizeVessel DWT LOA (m) Beam (m) Draft (m)

Cape Size 170000 285 45.6 18.3Panamax 70000 230 35 13

Although, smaller vessels like handymax can also be considered, the economics of shipping logisticsfavors Panamax and Cape ships.

1.12.2. Navigation Channel and Turning Circle

The depth of the water required to allow ship movement at any tidal stage is assessed at -15.5 m and -20.0 m for panamax and cape vessels respectively.

The turning circle diameter is 460m for Panamax vessels. Berth pocket will be provided -15m depth at alltimes so that the ship can remain at berth and depart during all tidal stages.

Based on the site characteristics presented in the width of approach channel required is assessed at250m.

1.12.3. Navigation Aids

These shall be provided along the channel, on the adjoining shoals and at lead points as per the IALAsystem applicable to this region.

1.12.4. Berth Layout

Orientation of berth is most suitable to be laid along the bank of river and in the direction of river flow as faras possible.



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To avail maximum advantage of water depth the berth face is envisaged to be located along an average-10m contour of the Anjanvel bay. The berth will be connected to shoreline by a trestle supported onpiles.

The length of berth provided is as follows

PANAMAX: berth length 270mCAPE: berth length 315m

1.13 Cargo Handling Equipment

To achieve 5 million TPA of throughput, fully mechanized unloading system is provided. The suggestedcoal unloading system is comprised of grab unloader to evacuate the ship and conveyor belt to transportcoal to yard. Depending on the equipment planning, maximum of two unloaders with 2000 TPH capacityeach with matching conveyor system would achieve a projected throughput of 12 MTPA given 300working days. At the storage yard, a provision of one stacker/ reclaimer is made for loading coal onward topower generation plant site.

1.13.1. Coal Discharge rates

Power plant at Dhopawe is expected to import 5,000,000 tonnes of coal by 2009-10 and 10,000,000tonnes by 2014-15. It is recommended to have an import conveyor with a discharge capacity of 40,000TPD. The jetty is designed for a load of 5 Tonnes/sq. m. Pressure exerted by the coal unloaders is withinthis working load.

Table 1-6 Typical Calculations for the discharge rates

Typical Calculation for the Discharge RatesCoal unloaders (numbers) 2Total Working Hours / Day 20Coal Discharged (Tonnes/day/unloader) 20000Coal Unloaded (tonnes per day) 40000

1.14 Environmental Aspect

The areas where dust suppression is required areAt ship unloaderBelt transfer points andStock yard

Suitable water spraying system shall be installed at these areas to bring emission levels to acceptableone. The conveyor system will be covered all along to minimize the pollution.

1.15 Marine Civil Works

1.15.1. Deck level of Berth and Trestle

Specific data on wave penetration at the berth location is not available. Therefore, a desk assessmentwas carried out to get approximate idea about wave conditions. Based on this, the elevation of deck isproposed at + 6.0 m CD which will not allow overtopping during severe wave and surge conditions.



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1.15.2. Structural Type

RCC pile structure with combination of in-situ and pre-cast members is suitable from cost andconstruction point of view.

1.15.3. Fender System

Panamax and Cape size vessels are considered for preliminary assessment of structural configurationand size. Detailed structural analysis using STADD software will need to be carried out at DPR stage.

Long rubber fenders would be appropriate. These will be installed on fender panel as shown on thedrawing. The system will be designed for berthing angle not exceeding 10 degrees and vessel speed of0.1 to 0.15 m/s depending on the tranquility levels. To allow berthing during all tide levels, a long rubberfender is provided.

1.15.4. Dredging Aspects

Geo-technical investigation has been carried out in the past by MMB. This borehole data and locationsare presented in drw.no 16 and 17. In order to prepare a technically adequate proposal, the approachchannel shall be provided from-15.0m contour and the turning circle shall be located where the river width isabout 1.5 times the width of the turning circle. To achieve this adequate dredging is required. It appears thatin the channel area the soil is loose to medium fine sand. Dredged slopes could remain stable.However, at DPR stage numerical stability analysis would be required to assess the stability.

1.15.5. Foundations

Geo-technical data in the nearby location shows that gray basalt rock is available at a depth of 14.0 m to15.0 m below seabed (source: Reference 2). However, looking at the dredged depths required at theberth pocket, it is anticipated that the founding level for piles would have to be located about -25m.

1.16 Equipment Details - Import Conveyor System

Belt conveyors and accessories shall be designed, fabricated, erected, tested and commissioned inaccordance with IS 11592.

1.17 Road Map

Hydrographic SurveyNumerical modellingBore hole at proposed sites for berthing and channel and turning circleSoil investigationEnvironmental Impact AssessmentSite Clearance from Maharashtra Pollution Control BoardCoastal Regulation Zone (CRZ) clearance from Government of India

1.17.1. Agencies

NIOTIITMNIOCWPRSIndomer Coastal Hydraulics Pvt Ltd



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1.18 Unconfirmed news that may impact development options

It is learnt that Gas Authority of India Ltd. (GAIL) has issued land acquisition notice to villagers ofNavgaon plans to lay gas pipeline across the river Vashishti from Dabhol side to a point betweenAnjanvel and Veldur.

If this were to actually transpire, it would rule out Dhopawe bay for direct berthing facility as it would not bepossible to dredge to the required depths. This may also jeopardize the location of the turning circleinside the river

1.19 Conclusions

After evaluating the functional requirements, the site conditions, and the capital and operating costs, i-maritime concludes that:

the proposed coal import facility seems technically feasible at Anjanvel Bay and Dhopawe Bay forboth options I and II (lighterage and direct berthing respectively), subject to confirmatoryinvestigations

based on net present value of capital and operating costs, direct berthing is a better (cheaper)option than lighterage and Anjanvel Bay is a better (cheaper) option than Dhopawe Bay

berthing facilities in phase I should be designed to have expandability, as deployment of capesizevessels (to be evaluated in DPR stage) could confer operating cost advantages over panamaxvessels in phase II

coal handling by lighterage option could pose practical difficulties in phase II, and scalability ofdirect berthing is higher than lighterage operations. Therefore, merits of direct berthing out weighlighterage.

1.20 Recommendation

i-maritime recommends that before locating the new facility, the requisite data required fordecision making be obtained through technical investigations at the DPR stage. This includes:Sub-soil investigation at the site, Hydrographic Survey, Wind Observation (direction andstrength), Wave observation (wave height and wave period), Mathematical modeling to studysediment transport from -15m contour line at sea to the turning circle, and Numerical model study toexamine the stability of the sand bar at the river mouth


Annexure 11 - I-maritime Techno-Eco Feasibility Report

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