technology watch
Melogale™ Wind Farm Performance Optimisation for Operational Site Management
Transforming SCADA data in to vital management information.
Background
In the operation of a wind farm it is essential that wind farm owners and operators can trace every kWh of generation achieved or lost as an analysis will allow targeted site expenditure on a past and future cost basis.
The aim of wind farm performance analysis is to provide a clear picture of the multi-faceted performance of a wind farm and its constituent wind turbines, and thus inform the decision-making of the management. An added benefit is to enabling direct comparison across a mixed portfolio of wind turbines.
Can I get this information from a site SCADA system?
There are a variety of SCADA systems particular to different turbine manufacturers and models, all designed to track performance in an automated fashion. Unfortunately, the reporting modules of SCADA systems rarely have the ability to resolve alarm cascades for a root cause; accurately categorise activity external to the turbine; or have the ability to combine intelligently with a work control system. Ironically, data loss by most SCADA systems is generally linked to periods of turbine downtime, meaning that the reporting accuracy is lowest when most required.
What is Melogale™ and how does it work?
Melogale™ is an analytical system, developed by Natural Power's Asset Analysis department. It takes the raw data generated by site SCADA, and, using a combination of automated and human processing, produces the most accurate picture possible of site performance from a variety of perspectives. Every period of turbine downtime is evaluated and categorised, and a power performance model derived for the site in order to accurately measure the cost of losses.
This can provide:
- A full picture of the impacts of turbine downtime, subdivided by subsystem and failure type, with the associated actual lost generation;
- A full list of downtime evaluated according to the warranted availability contract, for use in negotiations with manufacturers;
- Actual generation lost due to infrastructure and grid downtime;
- An evaluation of the reasons for deviations from periodic budget generation figures, with recommendations for budget revisions given known performance;
- A turbine-by-turbine assessment of power performance, showing where production is being affected either by power limitation or directional sensitivity and turbulence;
- Post-construction yield analysis, for deriving future projected yields;
- An analysis of trends in critical elements of the wind turbine to identify developing problems.
Melogale™ in current use
Melogale™ is currently in monthly use on 220MW of wind plant, covering 4 turbine manufacturers and7 models, as well as being applied to a large number of sites for bespoke analysis.
"Melogale™ has helped us to effectively target our site management and allows us to continually trace the gain and loss of generation and performance throughout our portfolio."
Where can I find out more?
Simply sayhello@naturalpower.com
ZephIR® - now RERL approved for wind measurements!.
The Renewable Energy Research Laboratory at the University of Massachusetts/Amherst (UMass) has successfully prepared and released an Assessment Report on Natural Power.s ZephIR® laser anemometer which is based on LiDAR technology. UMass has undertaken a data validation experiment which finds that the system achieves correlation of 0.98 up to the tested height of 118m in comparison to traditional cup anemometers.
In addition, ZephIR® was shown to perform strongly in a comprehensive uncertainty analysis with approximately 50% less overall wind speed measurement error to that of the in-situ cup anemometer. Based on a total of six months wind resource assessment, UMass reported that the system is acceptable for use in wind resource assessment applications.
Highlighted in the report, UMass believes that:
"the resource assessment portion of any wind energy project development process could be improved and streamlined by the substitution of LiDAR-based measurement in place of cup anemometers
The most important benefit associated with lidar wind resource assessment is that the LiDAR is capable of measuring wind speeds at the hub height of a modern wind turbine. When hub height data are available for analysis, access to financial capital for wind project development becomes less restrictive because wind shear extrapolation is one of the most detrimental sources of measurement uncertainty in a given wind resource assessment campaign."
It is for this reason that ZephIR® has now been approved to be added to the Renewable Energy Research Laboratory (RERL) suite of wind speed measurement devices.
The full report can be downloaded here: