Meeting the challenge of operational excellence

Paul Boughton

Operational excellence and sustainability are major goals for modern power plants and are being achieved both by modernisation of existing facilities and new builds. Sean Ottewell reports.

A major control systems and technology upgrade at 12 Puerto Rico Electric Power Authority (PREPA) sites has been completed by Invensys Operations Management. With 5839MW of generating capacity, PREPA is one of the largest public utilities in the USA and the sole provider of electricity for 1.5 million customers in Puerto Rico.

Under the terms of an agreement originally signed in 2010, Invensys supplied its Foxboro I/A Series distributed control system (DCS), including its new Foxboro Control Software solution, to help PREPA diversify its production capabilities and become more nimble as it begins to add renewable energy to its power mix (Fig.1). Invensys also provided field service and start-up support, as well as design, testing and implementation services, including access to its Power Centre of Excellence in Foxboro, Massachusetts, USA.

PREPA's total production capacity is expected to grow to 6719 MW by 2014. As a result, it has undertaken a multi-phase initiative to expand gas firing at all its generating plants, which will reduce air emissions, drive down the costs of other fossil fuels and spur wider economic benefits for the island.

Additionally, in order to meet new US Environmental Protection Agency hazardous air pollutant criteria, Puerto Rico's energy diversification law states that 12 per cent of PREPA's total output will have to come from renewable sources by 2015. This number increases to 15 per cent by 2020 and to 20 per cent by 2035. PREPA's current modernisation initiative will provide the company with an automation infrastructure that will make it much easier to integrate renewable fuels into its power production line.

"We recently initiated a long-term strategy to expand the use of natural gas and renewable fuels at our generating plants, which required modern systems and technology," said PREPA chief engineer Jose Mulero. "Invensys Operations Management's Foxboro I/A Series control technology, particularly its Foxboro Control Software, gives us the flexibility we needed to complete dual fuel conversion at all our targeted units, and we can do it sooner and with fewer costs. Because of the open nature of the technology, Foxboro solutions will help us provide reliable, cleaner energy in a safe, responsible and sustainable manner, as well as meet our long-term strategic objectives and comply with future regulations," he added.

"Our Foxboro DCS and Control Software offerings perfectly illustrate our commitment to innovation and open technology," said Gary Freburger, president of Invensys Operations Management's systems business. "Power companies are facing new, ever-more complicated challenges, even as their equipment and workforce continue to age. Instead of continuing to make like-for-like replacements or undertaking a major end-of-life installation in an attempt to meet these challenges, many of our customers, like PREPA, are choosing to modernise their existing systems. That can be the most cost-effective transition to improving real-time plant efficiencies and profitability. We are pleased to serve as PREPA's trusted partner and excited about the value we are able to deliver to them and their customers," he added.

Meanwhile Yokogawa Electric Corporation's subsidiary Yokogawa Middle East has received an order to supply control systems and operator training simulators for the Shoaiba II combined cycle power plant, which is being built in the Kingdom of Saudi Arabia (KSA) for the Saudi Electricity Company.

Located south of Jedda on the Red Sea coast, Shoaiba II will have ten gas turbines and two steam turbines with a combined output of 1200 MW (two blocks of 600 MW each) and is scheduled to start operation in June this year.

The order was placed by Daelim Industrial and covers a comprehensive solution comprising a CENTUM VP control system and a simulator which will be used to train operators under complex simulated plant operating conditions. The control system at the plant will be for the integrated control of heat recovery steam generators (HRSGs) and gas turbines. For the systems and products that make up these solutions, Yokogawa Middle East and its subsidiary Yokogawa Saudi Arabia will be responsible for project execution, including engineering, testing, installation and commissioning.

Yokogawa Middle East says it was able to secure this order due to factors such as its top platinum rating for 'Saudisation' under the Saudi government's Nitaqat programme. This began in 2007 with the establishment of two Yokogawa companies, Yokogawa Saudi Arabia and Yokogawa Services Saudi Arabia, to provide sales, engineering, and after sales services in the KSA. Also taken into consideration were Yokogawa's activities to promote professional education and provide employment in the country.

The company also points to additional contributing factors such as the engineering capabilities acquired since 2007, the close project support afforded through the global cooperation of the Yokogawa Group and the high functionality of its plant simulation solution for control function testing and operator training.

Encouraged by its success in being awarded this contract, Yokogawa says that it now aims to expand its controls business in the KSA by further targeting the power plant sector and other energy-related markets. [Page Break]

Indian coal power

Alstom Bharat Forge Power (ABFPL), the joint venture company between Alstom and Bharat Forge, has secured in India an order worth over EUR350 million to supply three units of 660 MW supercritical coal turbine islands to Nabinagar Power Generating. This is a joint venture between NTPC and Bihar State Electricity Board in Nabinagar, located in the state of Bihar.

ABFPL's scope of work includes engineering, manufacturing, supply, erection and commissioning of three 660MW supercritical units. This order is part of the NTPC bulk tender for the supply of 11,660MW turbine generator islands. This award follows the EUR250 million order won by ABFPL in April 2012 for the supply of two 660MW supercritical units to NTPC Solapur site in Maharashtra, India.

Alstom's supercritical technology uses steam with very high temperatures and pressure, resulting in a much higher efficiency (above 40 per cent) than conventional sub-critical coal fired plants. This means that a supercritical unit burns much less coal.

In the USA, Fluor Corporation has won a five-year contract from Oklahoma Gas and Electric (OG&E) to provide maintenance and construction services for all seven of its power generation plant sites in Oklahoma. The value of the contract was undisclosed.

The contract involves Fluor supplying supervision and craft personnel to support ongoing base crew maintenance as well as major outage and project work, construction services and plant modifications.

AMECO, Fluor's equipment, tool and fleet management unit, will provide complete craft support services at all OG&E project site locations associated with this contract.[Page Break

Contract operation and maintenace

Contract operation and maintenance services need to provide all the personnel and management systems necessary to safely commission, manage, operate, maintain, and administer the business and technical aspects of a power generating facility.

Over the years, Sterling Energy has gained experience and expertise operating a wide range of plant types including biomass, combined cycle combustion turbine, cogeneration, and aeroderivative-based peakers. The company has operated those plants in a variety of business contexts and so has built up a familiarity with merchants, power purchase agreements, and tolling.

For example, the company is currently commissioning and will operate a combustion turbine cogeneration plant in Canada.

The plant includes two LM6000 combustion turbine generators and two once-through steam generators. The cogeneration facility will sell energy into the Ontario merchant market and will provide steam to the Ford Motor Company.

In addition to mobilising and operating the new facility, Sterling Energy will continue to manage the adjacent Ford power plant - a situation that has been ongoing since 2007.

"We understand that the mission of every power plant business is two-fold. First, to provide exceptional returns to the investors by seeking every reasonable opportunity for increased revenues and reduced expenses, while optimising the balance between them. Second, preserve the value of the plant through cost-effective maintenance and the improvement of its human and physical assets," says the company.

Sterling says it also recognises that each step in the evolution of a power plant - from the development phase through maturity - presents a unique set of management issues, priorities, dangers, and needs for critical management systems.

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