Wind power, also known as wind energy, is the idea of using wind to produce mechanical power with the help of wind turbines. The turbines turn electric generators to give electricity. In more simple terms, it converts the wind’s kinetic energy into electrical energy.
Wind power is one of the fastest-growing renewable energy technologies today. According to the International Renewable Energy Agency (IRENA) 2016, wind energy contributed 16% to the electricity generated by renewable energy sources. Wind Turbines and wind farms are rising to the forefront, becoming an essential source of renewable energy. They are increasingly employed by many countries to reduce the use of fossil fuels.
The popularity of wind turbines emerges from their ability to provide clean energy, use minimal water, and produce no greenhouse gases and no waste products. If we use a one-megawatt turbine instead of one megawatt of energy from fossil fuel, we can save almost 1,500 tons of carbon dioxide.
Wind Turbines are very large structures, reaching over 140 mt all with blades that are 55m long. The wind energy market focuses on the lowest generation cost or Cost of Energy (CoE) which requires highly efficient wind turbines that function smoothly. Structural health monitoring is, therefore, very necessary to reach the efficiency level in the turbines. Moreover, health monitoring also prevents any turbine collapse which can be catastrophic.
The online web-based wind turbine monitoring service provided by Encardio Rite enables critical data at the client’s desk with automatic alerts, to warn the related authorities in case any of the monitored parameters breaches its trigger value. Encardio Rite also has expertise in advanced non-contact technologies used for safety monitoring and risk assessment of structures, such as automatic 3D deformation monitoring using ATS, laser scanning, and surveys using drones.
Encardio Rite offers several sensors that can be used for monitoring the foundations and towers of the wind turbines such as the vibrating wire embedment strain gages, VW sister bars, soil and concrete interface pressure cells, electronic plumb lines, liquid level settlement system, tiltmeters, multipoint borehole extensometers, etc. It also provides an online web-based monitoring service that allows important data at the client’s desk with automatic alerts and warns the related authorities in case the alert levels cross the trigger value. Apart from the sensors and online monitoring service, Encardio Rite also offers advanced non-contact technologies such as automatic 3D deformation monitoring using ATS, laser scanning, and surveys using drones.
Why do we need Wind Turbine Monitoring?
It is very critical to ensure the structural integrity of the tower and its components to ensure the low cost of energy and the safety of the surroundings. Due to the stochastic nature of the load regime faced by a wind turbine, it is essential to have a tailor-made structural health monitoring system. The wind Turbine Monitoring plan should cover monitoring the structural health of the concrete foundations supporting the tower and the tower itself.
Here’s why you need to monitor a wind turbine:
- To receive information on the prevailing state of the rock-to-foundation interface during the operation of its turbines.
- To enhance the turbine performance, improve durability, and reduce the loads.
- Advance decision-making and risk management process.
- Confirm the design and long-term performance of foundations.
- To collect data to discover the effects of natural calamities such as earthquakes, cyclones, and flooding on the wind turbine.
- Generating long-term reliable data
Read More: A Guide on Structural Health Monitoring (SHM)
Structural Monitoring Solutions – Wind Turbines
Encardio Rite offers a comprehensive range of sensors for the accurate performance and structural monitoring of wind turbines. The geotechnical instruments offered are important for the measurement of parameters like distribution along the pile or raft foundation, the effectiveness of lock-off bolts, tilting of the tower, movement between the foundation and the underlying soil/rock material foundation, etc.
Let’s take a look at some of Encardio Rite’s range of sensors and their application.
| Parameter | Instrument | Application Area |
| Foundation’s settlement (z) | Model EPS-12-60 topographical marker/surface settlement points | An upper surface of the wind turbine’s foundation |
| Model ESM-30V vibrating wire liquid level settlement system | The reference vessel is placed outside while the fluid-filled vessel in embedded in the concrete foundation |
| 3D movements (x, y & z) | Model ERT-20P2 mini prism target | Placed at the wind turbine’s tower. |
| Lateral movement (automatic) | Model EAN-52M vertical in-place inclinometer system with several biaxial probes with SDI-12 output mounted vertically in a borehole, connected in a daisy chain manner. | Measuring lateral movements of a pile foundation of the wind turbine during testing. Ideal for long-term monitoring. |
| Lub-surface lateral movement (manual) | Model EAN-26-MV manual inclinometer system containing a bi-axial digital inclinometer probe. |
| Sub-surface relative settlements | Model EDS-70V vibrating wire type multiple point borehole extensometer | In the pile/raft foundation of the wind turbine. |
| Yield-point’s d-EXTO Mk II multipoint borehole extensometer with up to six (6) Linear Variable Inductive Transducers (LVIT). |
| Change in tilt | Model ESDL-30MT or EAN-95MW (RF) tiltmeters | At the upper surface of the foundation and the tower’s body |
| Crack monitoring | Model EDJ-40V vibrating wire crack/joint meters or EDJ-40C2 Mechanical bi-axial crack meter | Across the existing cracks in the foundation |
| Tension in tie-down anchors for stabilizing the foundation | Model ELC-30S resistive strain gage type center hole load cell or ELC-32V vibrating wire type centre hole load cell | Top of the foundation or between the locking nut or wedge plate of the tie-down anchor |
| The load applied on the foundation’s pile during testing | Model ELC-150-SH high-capacity compression load cell | At the top of the pile during testing |
| Stress at the concrete soil interface | Model EPS-30V-I vibrating wire soil-concrete interface pressure cell | At the turbine’s foundation base |
| Model EPS-30V-J jack-out pressure cell | At the base of the pile foundation |
| Strain in the foundation and the tower | Model EDS-20V-E embedment/ EDS-20V-AW arc weldable strain gage/ EDS-12V sister bar strain gage | Set in the foundation attached to the reinforcement cage or fused to the tower’s structure at the base and other essential positions |
| Movement of the top of the tower relative to the foundation | Model EDS-50 normal plumb line with model EPR-01S telecoordinometer to monitor relative horizontal movements in x & y planes | Invar wire of the plumbline to be anchored to the top of the wind turbine’s tower |
Read More: A Guide on Geotechnical Instruments: Types, & Application
Encardio Rite provides data loggers with a GSM/GPRS modem that efficiently stores and transmits data from the sensors to the main server. Model ESDL – 30 SDI-12 data logger has interface cards available for conversion of sensor outputs to SDI-12 digital output, where the sensors do not have an SDI-12 interface output.
Encardio Rite also offers several shielded armored and unarmoured cables ranging from 2 to 40 cores that connect the sensors to the readout unit. Splicing kits, junction boxes, switch boxes, protective enclosures, and covers, and lockable manhole covers are promptly available for all kinds of instrumentation schemes. It also provides multiple solutions to reduce cable lengths by using multiplexers, SDI-12 interface, and wireless transmission.
Encardio Rite protects the sensors against voltage spikes with the help of a tripolar plasma surge arrester built into most sensors. However, for complete security, an additional lightning protection system is recommended. We recommend getting in touch with a local agency specializing in earthing and lightning protection systems to achieve additional protection.
To allow for 24X7 near real-time data access during wind turbine monitoring, Encardio Rite provides an online web data monitoring service (WDMS) that displays the sensor data in the form of graphs, tables, overlaid on georeferenced maps, site plans, etc. It also offers an automatic alarm system to authorized users at different locations, on their computers/laptops.
The data observed from the monitoring and instrumentation of the sensors play a vital role in protecting the structure, surrounding communities, and the environment. It also provides enough time to take collective measures in case of any warnings. If we look at the cost of monitoring solutions and compare it to the loss incurred in case of any wind turbine failure, it would be clear that it is better to monitor that bear the cost.
As the work is of a critical nature, the instruments installed and the manpower deployed for installation, monitoring, and maintenance of instruments must be efficient, reliable, and of high quality. Encardio Rite offers the most robust service owing to its vast range of experience in manufacturing and monitoring in the field. Cloud-based data management solutions offered by Encardio Rite make the processing and analysis of the collected raw data easier and provide quick dissemination of meaningful information to the concerned personnel and stakeholders located anywhere in the world.