The Importance of Redundancy

The word redundant has an admittedly negative connotation. Duplicative software and costs are usually the first to fall under the ax of efficiency. If two tools are doing one job, why not drop it?

Let’s explore this in more detail within the context of wind operations.

Wind turbines need attention to keep them in peak operating condition. Anything less and there are energy and revenue losses. Optimum operating condition means the parts and components are in good condition, and the performance of the turbine is as close to the expected power curve. (Note this might not necessarily mean the OEM warranted curve, but the long-term reference curve of each individual turbine. See here: The Importance of the Long-term Reference Curve)

A variety of methods are used to check the condition of the turbine periodically, each having its own importance: inspections (visual, vibration, oil sampling, photo/video) and remote monitoring of the data (real-time and periodic analysis of longer datasets).

Let’s focus on the periodic analysis of SCADA data, both performance and component health. This is normally done by an asset manager using one or more pieces of software to write reports at regular intervals. Most companies, but not all, have data analysts or specialist performance engineers who investigate potential issues and power curve anomalies to come to conclusions about whether there is an issue or defect, and decide if there is a need for a follow-up action which could range from “just watch it” to “stop the turbine and act now.” Note there is a limited number of wind turbines that an asset manager can manage, so the larger the wind fleet the more asset managers are needed or the more the work gets subcontracted. On the data analysis side, the specialist can analyze many more turbines, with no theoretical limit, but it’s the decision-making about the follow-up actions that is complex. Don’t forget the stakes: miss an issue, lose energy; schedule a person to climb a turbine when nothing is wrong, unnecessary costs, a waste of time, and ultimately a loss of energy. Secondly, the frequency of analysis is not always consistent. Does the process need to be triggered manually? Is the entire process repeatable and well-documented? How many people can complete the process from A to Z? What happens during holidays, travel, illness or when unforeseen distractions arise? Having a second person or even more, provides security that important processes can continue without interruption.

Only when redundancy is built into every step of a process does the safety net approach become invaluable. When do you need a safety net? Only when something breaks or an error leads to a fall. Visual inspections sometimes miss temperature issues in SCADA. SCADA data misses something visually obvious. Oil quality sampling can miss a vibration pattern. Vibration monitoring can miss something that an analyst misinterprets. These are just a few examples.

It’s like building a net. There is value in multiple approaches. More methods improve the chances of detecting something potentially costly. The simplistic view that “this is already being done by one person one way” has more risk and potentially more costs over the long-term.

Build in some redundancy to your processes and organization. View each of them as an important rope in the net that you build and improve over time. Strengthen your net with new approaches including low-cost SCADA analytics to connect the dots. Through using many individual initiatives will your net become broad, strong and reliable.