Generating Station Uses OPC to Automate Processes

Santee Cooper’s Rainey Generating Station chose OPC solutions from MatrikonOPC to gain a step change in efficiency and meet the 98 percent uptime emissions reporting requirements.

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South Carolina’s Santee Cooper is a state-owned electric and water utility that generates the power distributed by the state’s 20 electric cooperatives. It serves more than 138,000 retail customers in Berkeley, Georgetown, and Horry counties, and supplies power to the municipalities of Bamberg and Georgetown, 32 large industries, and one military installation in North Charleston. Santee Cooper’s Rainey Generating Station (RGS), located near Anderson, S.C., is the company’s first natural gas-fuelled combustion turbine generating plant.

The main goal at the Rainey plant was to maximize the efficiency of operations. It also needed a method to send environmental data to the Continuous Emissions Monitoring System and reduce manual data collection processes. This was inefficient in the past, because there were many isolated data sources that could only be accessed manually.

A significant part of that challenge was collecting and accessing the data required for U.S. Environmental Protection Agency (EPA) reporting. Says William R. Finn, the team leader of the Performance Services Engineering Group at Santee Cooper, “We use Continuous Emissions Monitoring Systems (CEMS) to collect data for the Environmental Group at Santee Cooper. The CEMS provides information on gas turbine operation to ensure environmental standards are enforced.” Finn continues, “This system is critical. It must function correctly and the data stream must be continuous. Emission reporting requires a minimum 98 percent uptime. Failure to meet reporting standards could result in fines and other penalties.”

At Santee Cooper, generation power meters were isolated data sources. Control room operators manually read the meters, recorded the data on paper, keyed the data into an Excel spreadsheet and transferred the resulting hourly data to a corporate intranet web site. This process was prone to operator input error.

To answer these challenges, says Finn, the company needed to automate processes and make data easily available to all levels of the operation. “We wanted a solution with vendor neutral architectures that enabled us to use existing legacy hardware. We were also looking for a scalable solution based on standardized technology that allows us to upgrade both software and hardware systems. MatrikonOPC, [located in Edmonton, Alberta, Canada], provided the solution we needed.”

Now, the station retrieves the data in real time from devices through a firewall between the control network and the corporate network. Data is retrieved from gas turbines through the MatrikonOPC Server for GE MarkVI, passed through the MatrikonOPC Redundancy Broker and MatrikonOPC Data Manager to the MatrikonOPC Server for Modbus.

The data is pushed into Data Logger where it is recorded and then used for reporting. The client applications are custom developed using Microsoft Visual Basic for real-time display. Notes Finn, “We configured Microsoft Excel to accept the OPC data being generated and display it in an Excel spreadsheet interface. By adding some Visual Basic code, we were able to turn Excel into a real-time data visualization tool.” Operators can access real-time environmental data in a user-friendly interface. MatrikonOPC ScadaModbus feeds the data into this Excel spreadsheet for real-time data calculation.

Continues Finn, “Before OPC, we had no way of accessing real-time data. Now it is readily accessible and we are reading and writing to 14,000 points every five seconds. Real-time data was also added to an existing RTX data historian for future analysis. The MatrikonOPC Redundancy Broker and Data Manager solution makes our system fully redundant, addressing our need of continual data for emissions reporting.”

Improved Plant Efficiency

OPC technology provides ease of access to the wide variety of devices in the enterprise, eliminating costly custom or proprietary interfaces and providing a flexible and scalable solution to build on for years to come. Adds Finn, “We are confident and secure in our ability to meet the 98 percent uptime emissions reporting requirements. Now that these manual processes are automated, we are saving approximately four hours of resource allocation in a 24-hour shift rotation.”

Rainey was the first Santee Cooper plant to implement the OPC solution. The success in automating what were once manual tasks at RGS will be employed across all of the Santee Cooper plants. “We will be connecting a weather station that is currently an isolated data source, using OPC to see ‘real-time’ data and use the historical data to better forecast dike maintenance. The Performance Services staff at Santee Cooper is extremely excited about benefits of OPC, its ease of installation and simplicity of use,” Finn concludes.

MatrikonOPC, a charter member of the OPC Foundation, is a developer, trainer and distributor of OPC products. For free downloads or more information visit www.matrikonopc.com.

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