Interview with Peter Clive, technical development officer, SGURR Energy Ltd: Understanding the utility of SCADA data in optimising wind farms performance

The data routinely acquired and stored by SCADA systems represents a vast amount of valuable information about the performance of wind turbines.

The information that can be extracted from this data is potentially of great benefit in terms of enabling accurate revenue variance attribution, well informed O&M strategies and infrastructure configuration, pro-active and pre-emptive intervention to alleviate anomalous performance, and the tuning of operational parameters to maximise revenues.

However, this information has historically been widely neglected because of the resource necessary to extract it from the data, according to Peter Clive, technical development officer, SGURR Energy Ltd.

"It has often been considered worthwhile to analyse the data only once something has already gone wrong with a turbine. However, analysis that have hitherto been conducted in a reactive, post hoc manner to diagnose faults or to progress post investment appraisals are now being automated, radically reducing the resource necessary to conduct them, and new tools have been developed which further enable rapid performance assessment and enhance its value. Rapid performance assessment enables routine performance assessment from which all the benefits of a more pro-active approach can be derived," said Clive, who is scheduled to speak during Wind Energy Operations & Maintenance Summit 2008, scheduled to take place in London on 11-12 November this year.

In a conversation with windenergyupdate.com, Clive shared that one current trend is the move towards data aggregation among owners, operators and network management of multiple wind farms: the data from multiple disparate SCADA systems installed at multiple wind farms is put into a common format for centralised asset control in a "SCADA on top of SCADA" setup.

This enables more efficient review of the performance of portfolios of wind farms and is also used in some instances to assist forecasting.

The full benefits of this trend have not been realised as in general the full potential for performance assessment is not being exploited.

Clive added that another interesting trend is the ongoing investigation of exactly how much information can be extracted from routine SCADA data.

"For example, an active topic of research that is informing our approach to performance assessment is the extent to which the stresses the machine is subject to, arising from, for example, turbulence, wind shear and veer, and flow inclination, can be discerned using standard performance assessment tools. This field is one of the most rapidly progressing fields in a rapidly developing industry and SgurrEnergy engages in continuous innovation to remain at the cutting edge delivering the maximum achievable benefit to its clients," said Clive. 

"One possible benefit of third party performance assessment in the future is the possibility it raises for the continuation of the trend towards data aggregation such that performance assessment in terms of turbine inter-comparison is not conducted relative only to other turbines within the same individual wind farm or even within a single portfolio but rather extended to encompass entire fleets. In this way, the performance of an individual turbine can be routinely compared to the performance of every other turbine of the same make and model to derive the maximum benefit," he said.  

"The development of offshore wind farms poses its own unique set of O&M problems, and the ability to conduct routine performance assessment is of particular benefit in this context, where it may ultimately be viewed as a sine qua non."

A SCADA system should naturally be highly reliable

SCADA systems, which implement Supervisory Control And Data Acquisition, are operational (rather than analysis) tools. "In general, the most valuable analysis of turbine performance are not implemented by the SCADA system per se but by the tools with which the system may be augmented for the purposes of performance monitoring and assessment and which utilise for that purpose the data routinely acquired by the SCADA system," said Clive.

Citing an example, Clive said some limited turbine inter-comparison and performance trending is sometimes performed by reporting modules of SCADA systems but the most sophisticated analysis delivering the greatest benefit are beyond the scope of essential supervisory control and data acquisition implemented by SCADA.

In order to facilitate performance assessment, a SCADA system should naturally be highly reliable.

Event data such as alarms, warnings, and log entries, should adequately record the events they describe, pointed out Clive. The time series data should include status fields recording the duration of specific conditions during each averaging interval. Good retention of and easy access to historical data is a requisite.

 "Simplicity is a key feature when it comes to integrating the system into a data aggregation strategy," shared Clive.

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Wind Energy Operations & Maintenance Summit 2008

Peter Clive, technical development officer, SGURR Energy Ltd is scheduled to speak during Wind Energy Operations & Maintenance Summit 2008, to take place in London on 11-12 November this year.

For more information, click here:  http://www.windenergyupdate.com/wind08/programme.shtml

Or contact Ian Evans (ian@eyeforenergy.com, +44 (0) 207 375 7575)