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Construction : Case Study | February 2016 | Source : Infrastructure Today

Against All Odds

Photon Energy Systems successfully carried out an EPC contract for a 5 MW grid connected solar photovoltaic power plant project in Port Blair for NTPC Ltd.

NTPC commissioned a 5MWp grid connected solar Photo Voltaic (PV) power plant project in Port Blair, Andaman & Nicobar (A&N) Islands. The project was executed by NTPC on a build-own-operate basis through a memorandum of understanding (MoU) it signed with the A&N Islands administration.

The project is spread across a 10-hectare plot that has been leased out for a period of 25 years by the A&N electricity department, who is the plant´s customer. NTPC awarded the Engineering, Procurement, and Construction (EPC) contract to Hyderabad-based Photon Energy Systems Ltd. The project was completed within six-and-a-half months from the date of handing over of the land, in spite of several challenges.

Project Objectives
NTPC set out with the objective to produce environment-friendly, sustainable energy that would assist in saving diesel, reducing and saving foreign exchange outflow, and bringing down the country´s carbon footprint.

´This was a highly complex project because of the challenges associated with a compressed project schedule and working in a remote island that is separated from the nearest port by over 1,000 km. We adopted robust project lifecycle methodologies even before the project was awarded to the time it was commissioned,´ said AK Jha, Chairman and Managing Director (CMD), NTPC Ltd.

NTPC floated a tender for the EPC contract based on competitive bidding. Photon Energy Systems Ltd won the EPC contract. The project was monitored and controlled with the help of a proven project monitoring system to avoid any slippages.

The Challenges
The primary challenge was to execute the project that was away from the mainland within the time schedule (within FY 2012-13). Detailed below are the various other project specific challenges:

Logistics in Supply Chain
Transportation by ship from Chennai to Port Blair faced a bottleneck as ships sailed from Chennai to Port Blair only on specified days of the week. This caused delays; certain equipment reached the site just one week before the project was commissioned.

Suppliers
During project execution, one critical supplier of module structures was not able to adhere to the schedule. Its manufacturing capacity could not keep to the quantity required and its process facility was inadequate to meet the specification and quality requirements. The project team had to scout for an alternate source for this structural member.

Human Resources
Port Blair did not have an adequate number of skilled workers. There was a shortage of electricians, cable jointers, and riggers. Coordination between multiple project teams that were geographically scattered was also a challenge, considering that the team had only six months to execute the project.

Communication
This was a project that required NTPC to collaborate at different levels - with the EPC contractor, sub-vendors, the customer, the local administration, and the local community. Limited communication facilities in Port Blair, including slow Internet speed due to limited bandwidth allocation, posed serious communication bottlenecks during the peak of project execution.

Other Challenges
Inclement weather/heavy monsoon rains for almost a month during the peak project construction period of six months added to construction woes.

The project also had to abide by a height restriction of a maximum of two metres from the ground that is imposed by the Airports Authority of India.

Project Management Techniques
R Venkateswaran, Regional Executive Director (South), NTPC Ltd said, ´We followed our internal, Integrated Project Management Control System (IPMCS), which is in line with international standards such as PMI´s A Guide to Project Management Body of Knowledge (PMBOK® Guide). IPMCS helped us transition the project smoothly across its lifecycle through close monitoring, coordination, interface management, and timely decision-making. It was one of the major contributors behind the project´s success in a limited time frame.´

Scope
NTPC overcame scope challenges with a detailed ´sensitivity analysis´ to determine changes in the annual energy generation because of changes in the irradiation level. For the annual generation figure, NTPC based its estimates on the worst case scenario to provide a margin of safety while determining the project viability.

Logistics in Supply Chain
There was close coordination between manufacturing and supplies. To save time on shipments, six main inverters and one spare set were airlifted from Germany to Chennai, and thereafter transported by ship to Port Blair.

Suppliers
Special teams were deputed at the sites of major vendors to inspect, clear, and follow up on critical supplies and equipment due for dispatch. Teams used imaging technology and electronic transfer of documents and images for speedy submission and approval of vendor drawings, data sheets, and work documents.

Human Resources
A full-time Project Management Office (PMO) was set up during execution. Strict implementation of NTPC´s field quality assurance system, safety standards, and commissioning procedures in Port Blair ensured workforce safety. Workers´ safety and wellbeing were also enforced through regular site visits and interactions with supervisors.

Communication
The project management team conducted regular monitoring of the project´s progress. All design and engineering activities including preparation, submission, review, revision, and final approval were fully automated through paperless, Internet-based applications.

Supplementary Solutions
Since the low lying areas on the island are always waterlogged due to regular, heavy rainfall, extensive arrangements were made to clear out the area throughout project execution.

Excavators and rock cutters for earth pits, and drill machines for laying foundations and cable trenches in rocky terrains were used. The project was executed 24x7 under floodlights powered by diesel generators.

Lessons Learned
To ensure that the land is in physical possession without any encumbrance well before the EPC contract is awarded.
To create adequate buffer time for dispatch and delivery activities for projects in remote locations that require multi-mode logistics.
To provide for adequate stock of spares of construction machinery at the site to avoid delays due to machinery breakdown.

Benefits
The NTPC solar PV project supplies clean and green solar energy to the A&N grid that supplies power to the island. It helped reduce carbon dioxide emission by 6,173 metric tonne during the first year of operation.

As a UNFCC registered plant, it received 6,173 CERs during the first year of operation (2013-2014). These tradable CERs have provided NTPC an additional source of revenue in the CER market.

The project was completed not only within the time, cost, and quality prescribed but also with a safety record of zero accidents during the construction and operations phases.

The project went on to win NTPC´s Swarn Shakti Award for excellence in project management for renewable projects that was instituted for the first time in 2012-13.

Energy Export Targets
Net energy to be exported - 69,38,000 kilowatt hour (kWh) units per annum, i.e., 6.938 million units per annum(Equivalent to the requirement of around 6,000 dwelling units)Annual Capacity Utilisation Factor (CUF) on net export basis û 15.84 per cent

A Few Project Highlights

  • 4,440 micro pile foundations
  • 450 metric tons of galvanised iron support structures (888 structures)
  • 21,312 mono crystalline solar PV modules of 235 Wp each
  • 1164 DC lightning arresters (Franklin Rods)
  • About 100 km of power/control cables and optical fibre cables
  • 6 outdoor type inverters of 800 kW each
  • Supervisory Control and Data Acquisition system
  • Control room building of 250 sq metre
  • About 3 km of internal roads

Total manpower employed during peak construction time -100 approximately

 
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