The wind pays for the asset.
The measurement decides how much.
Wind farms, solar sites and hybrid generation depend on measurement that holds up from the resource campaign through to the operating record. Gill ultrasonic wind measurement, 3-axis turbulence sensing, solar and environmental monitoring and machinery condition sensing are built for exactly that.
We aim to respond in one working day.
Yield assumptions become contracts, and contracts get audited
A renewable asset is financed against a yield model, and that model is built on measured wind. Every stage after it, power curve verification, availability warranties, performance ratio reporting and settlement, refers back to a measurement someone took.
That makes instrument selection a commercial question rather than a technical one. A sensor that drifts, ices or seizes does not just produce bad data. It produces data that cannot be defended when a warranty claim or a curtailment dispute turns on it.
The measurement therefore has to do three jobs: stay reliable where a visit needs a crane and a weather window, reach the controller or platform that acts on it, and stand up when a warranty claim or a curtailment dispute turns on it.
Renewable energy runs on measurement
From the wind arriving at the rotor to the condition of the machinery converting it into power, renewable assets depend on measurements that have to stay reliable in difficult environments and over long operating lives.
Ultrasonic wind measurement, three-axis sensing, environmental monitoring, non-contact position sensing, liquid level measurement, oil debris monitoring and independent calibration cover the whole renewable-energy measurement chain.
Wind. Turbulence. Position. Irradiance. Environment. Machinery condition.
The measurement changes with the application. The engineering discipline does not.
Where independent verification is required, Labcal provides UKAS-accredited calibration for equipment from multiple manufacturers across six measurement parameters, so a site can manage its whole instrument schedule with one specialist laboratory.
Access is a crane and a weather window
A nacelle sensor cannot be reached without stopping the turbine, and on an offshore or upland site without a weather window too. Anything that needs regular attention gets attended to late.
0 moving parts to seize or replace
Icing turns a wind sensor into a liar
A cup and vane anemometer that ices up stops rotating and reports calm. The turbine acts on that reading, and the loss is invisible until someone compares it against a neighbour.
Icing tested to MIL-STD-810F
Turbulence is where the yield model fails
Wake effects, shear and flow inclination are what separate the modelled yield from the measured one, and none of them are visible to a 2-axis sensor.
WindMaster Pro measures all three axes to 32 Hz
The number has to survive an audit
Power curve verification, availability warranties and curtailment disputes all turn on a measured wind speed. Traceable calibration is what turns a reading into evidence.
UKAS-accredited, ISO/IEC 17025:2017
Every renewable decision starts at a measurement point
A renewable site measures across the whole asset. Wind at the nacelle and on the mast. Turbulence and shear across the rotor. Irradiance across the array, ambient at the substation, and the condition of the machinery below.
Nacelle-mounted wind sensor
Yaw and pitch are set from the nacelle reading, so an error there is not a data problem, it is lost yield on every hour the turbine runs.
- WindObserver 75 turbine-control accuracy 1 percent within 25 degrees of datum
- WindObserver 90 0 to 90 m/s where the site sees extreme gusts
- WindSonic M heated aluminium, operating to -40 degrees C
Met mast at hub height
The hub-height reading is the reference the whole power curve is argued from, and it has to survive a decade on a mast nobody climbs lightly.
- WindObserver 75 316 stainless open head, no moving parts, IP66
- WindMaster Pro 3-axis to 32 Hz for turbulence intensity
- MetConnect THP adds air density from temperature, humidity and pressure
Lower mast levels and the shear profile
Wind shear across the rotor is what turns a good site into a marginal one, and you only see it by measuring at more than one height.
- WindObserver 70 heated head for a second and third measurement level
- WindSonic 60 0.5 kg, low cost per additional level
- MetConnect THP WMO-compliant separation of sensors by height
Blade pitch and yaw position feedback
Pitch and yaw actuators run millions of cycles across a turbine life, and a position sensor with contacting parts is a scheduled failure.
- Blade position sensors non-contact inductive, linear and rotary
- Blade60 contactless linear position feedback
- Blade360 contactless rotary position feedback
Gearbox and main bearing condition
A gearbox failure means a crane, a weather window and weeks of lost generation. The wear shows up in the oil long before the vibration.
- WearDetect oil debris sensing for ferrous wear particles
- WearDetect with display local indication alongside the output
- LevelPro lube and hydraulic level with no moving parts
Hydraulic and lubrication fluid level
Level in the tower base is checked on a service visit, which on a remote site can be months apart.
- LevelPro capacitive level sensing, no moving parts
- LevelLite level measurement for smaller reservoirs
- DD1615 level display local display for the level output
Substation and grid connection
Transformer ratings derate with ambient temperature, so the substation needs its own measurement rather than the site average.
- MaxiMet GMX500 wind, temperature, humidity and pressure in one unit
- MetConnect THP accepts Pt100 and analogue inputs from existing kit
- WindSonic 60 a local wind reference for the compound
Solar array irradiance and soiling
Performance ratio is only meaningful against measured irradiance, and a soiling loss you cannot see is a soiling loss you do not clean.
- MaxiMet GMX301 solar radiation only, 0 to 1600 W per square metre
- MaxiMet GMX551 wind, T, H, P, solar and rainfall in one station
- MaxiMet GMX501 wind, T, H, P and solar without rainfall
Battery storage containers
Battery containers are rated on ambient temperature and airflow, and derating on a hot still day is a commercial event, not a technical one.
- MetConnect THP temperature to 0.2 degrees C, humidity to 1.5 percent RH
- MaxiMet GMX300 temperature, humidity and pressure, no wind
- WindSonic 60 airflow reference at the container face
Control building and SCADA
The measurement is only useful once it is inside the system that acts on it, in the protocol that system already speaks.
- MetConnect One Modbus RTU and ASCII, SDI-12 v1.3, NMEA 0183
- WindObserver 75 RS422 and RS485, Modbus RTU variant available
- MaxiMet GMX551 one cable, one output string into the logger
Crane pads and construction lifts
A nacelle lift stops at a defined wind speed. The argument afterwards is always about what the wind actually was.
- WindSonic 75 0 to 75 m/s, full-range accuracy published
- WindObserver 90 0 to 90 m/s for exposed lifts
- MaxiMet GMX200 wind only, 0.5 kg, for a temporary works mast
Turbulence and wake effects
Wake losses across a row are the difference between the yield model and the revenue, and measuring them needs the vertical component.
- WindMaster Pro 3-axis, 32 Hz, 0 to 65 m/s, stainless steel
- WindMaster 3-axis to 20 Hz with a 32 Hz option
- R3-50 50 Hz research-grade 3-axis for detailed studies
Icing and cold-climate operation
An iced cup anemometer reports a false calm, and a turbine that trusts it stops earning while the wind is still blowing.
- WindObserver 75 heated head, icing tested to MIL-STD-810F
- WindSonic M heated aluminium body, operating to -40 degrees C
- WindObserver 70 heated, operating to -55 degrees C with heating
Precipitation and site conditions
Rainfall matters for erosion, access and soiling, and on a remote site the maintenance burden of the gauge matters as much as its accuracy.
- TruMet PW100 optical, 0 to 200 mm/hr, no moving parts to block
- MaxiMet GMX551 rainfall alongside wind, T, H, P and solar
- MetConnect THP contact-closure input for the TruMet pulse output
Site assessment and pre-construction survey
The measurement campaign that sets the yield assumption is the single most expensive number in the project, and it is taken years before revenue.
- WindMaster Pro 3-axis for turbulence intensity and flow inclination
- WindObserver 75 the long-duration reference on the mast
- MetConnect THP air density from temperature, humidity and pressure
Calibration and verification
A power curve warranty is argued from measured wind. Traceable calibration is what makes that measurement admissible.
- UKAS-accredited air velocity calibration traceable certification for anemometers
- Multi-parameter calibration six parameters, equipment from any manufacturer
- Recalibration scheduling intervals, reminders and turnaround
Find your renewable application
Six renewable energy applications where measurement, integration and calibration meet the demands of an asset life measured in decades.
Wind Turbine Control
Point the rotor at the wind that is actually there
Yaw and pitch control act on the nacelle wind measurement continuously, so a small persistent error becomes a large annual number. The sensor has to hold accuracy through icing, salt and a decade of service intervals that need a crane.
Engineering: Ultrasonic wind measurement, turbine control accuracy, traceable calibration.
Site Assessment and Resource Measurement
Build the yield model on measured conditions
A pre-construction campaign sets the yield assumption years before the first unit of generation. It needs hub-height wind, shear across multiple levels, turbulence intensity and air density, recorded continuously and defensibly.
Engineering: 3-axis turbulence measurement, multi-level masts, air density measurement.
Turbulence and Wake Measurement
Measure what the wind model cannot see
Wake interaction between rows, terrain-driven shear and flow inclination all reduce yield in ways a single wind-speed reading cannot show. Measuring the full three dimensional vector is what makes the loss visible and arguable.
Engineering: 3-axis and research-grade anemometry, flux-style measurement, integration.
Solar and Hybrid Sites
Performance ratio needs measured irradiance
Solar performance is reported as a ratio against available irradiance, so the reference measurement is doing commercial work. Add wind, temperature and rainfall and the same station supports soiling, tracker limits and module derating.
Engineering: Solar radiation measurement, compact weather stations, environmental monitoring.
Drivetrain and Machinery Condition
Know what is happening inside the machine
Renewable assets depend on machinery that has to run reliably for long periods, often where inspection is difficult. WearDetect trends fine and coarse ferrous debris in the oil between inspections, while level and position sensing cover the hydraulic, pitch and yaw systems around it.
Engineering: Oil debris monitoring, capacitive level sensing, non-contact position feedback.
Construction and Major Component Lifts
Make the measurement behind the decision defensible
Nacelle and blade lifts stop at a defined wind speed, and the decision is made from a temporary mast on an exposed site. Both the reading and its traceability matter when a stoppage is costed afterwards.
Engineering: Ultrasonic wind measurement, temporary installations, UKAS-accredited calibration.
insight
Why renewable measurement is a 3-axis question, not a wind-speed one
Most site conversations start with wind speed and stop there. The yield model does not. It depends on turbulence intensity, wind shear across the rotor and the inclination of the flow, and those need the vertical component that a 2-axis sensor does not measure.
The WindMaster Pro measures the full three-dimensional wind vector at up to 32 Hz across 0 to 65 m/s, in a stainless steel head. For the operating turbine, the WindObserver 75 carries a turbine-control accuracy of 1 percent within 25 degrees of the datum, with 1 degree on direction.
Gill was amongst the first to commercialise ultrasonic wind measurement, removing the bearings and moving parts that wear, seize and foul. That matters most where the sensor is at the top of a tower and the maintenance visit needs a crane.
The vertical component is what turns a wind record into a yield explanation. Without it, the gap between the modelled number and the measured one has nowhere to go.
Renewable energy technologies
Products and services engineered for renewable sites, spanning wind measurement, 3-axis turbulence sensing, solar and environmental monitoring, industrial sensing and calibration across Gill.
Meteorological Technology
WindObserver
Heated 316 stainless open-head 2-axis anemometer
The nacelle and mast workhorse. The WindObserver 75 carries a turbine-control accuracy specification, and the range is heated and icing tested.
WindMaster
3-axis ultrasonic anemometer
Measures the full three-dimensional wind vector, so turbulence intensity, shear and flow inclination become measurable rather than modelled.
MaxiMet
All-in-one weather station, no moving parts
One unit, one cable, one output string. The GMX301 is the solar-only node; the GMX551 adds wind, temperature, humidity, pressure and rainfall alongside it.
MetConnect
Separable weather station with third-party inputs
The answer when sensors have to sit at different heights for a shear profile, or when existing site instruments need to feed the same station.
Industrial Sensors
WearDetect
Oil debris sensor
Monitors lubricating oil for ferrous wear particles, so gearbox and bearing wear is visible before it becomes an unplanned crane visit.
Blade position sensors
Non-contact inductive position sensing
Linear and rotary position feedback with nothing in contact, for actuators that run millions of cycles across an asset life.
Level sensing
Capacitive liquid level sensors
Lube, hydraulic and coolant level with no moving parts, for reservoirs that are only seen on a service visit.
UKAS-accredited calibration for six measurement parameters
Labcal is an independent UKAS-accredited calibration laboratory, Lab 0625, operating to ISO/IEC 17025:2017. It provides calibration across gas and air flow, air velocity, liquid flow, pressure, temperature and humidity, all under one roof.
For renewable measurement that includes anemometers, Pitot tubes and thermal probes, alongside pressure gauges and transducers, thermometers, temperature and humidity probes and data loggers. Labcal supports equipment from Gill and other manufacturers, so a site can consolidate an instrument schedule that was never bought from a single supplier.
01 · Gas and air flow
Gas meters · Mass flow controllers · Dispensing systems · Low-flow laboratory to higher-flow industrial
02 · Air velocity
Anemometers · Pitot tubes · Thermal probes
03 · Liquid flow
Flow meters and sensors · Process control equipment · Water used for the accredited capability
04 · Pressure
Gauges · Transducers · Manometers · Transmitters
05 · Temperature
Thermometers · Probes · Thermocouples · Data loggers
06 · Humidity
Hygrometers · Probes · Transmitters
The measurement has to reach the controller that acts on it
Renewable measurements are almost never read by a person standing next to them. They feed turbine controllers, SCADA and asset management platforms, so the interface is part of the specification rather than something to solve after the sensor has been chosen.
Whether the requirement is Modbus into an existing SCADA, an SDI-12 network across a met mast, or a bespoke embedded solution, Gill engineers can support integration from specification through commissioning.
Outputs and options
- Modbus & SDI-12 : Multi-sensor masts and SCADA networks
- RS422 / RS485 : Serial into turbine controllers and loggers
- Analogue & Pt100 : Bringing existing site instruments into one station
- Heated variants : Cold climate and icing conditions
Why renewable programmes specify Gill
Accuracy where it earns money
The WindObserver 75 carries a turbine-control accuracy of 1 percent within 25 degrees of the datum, and the WindMaster Pro measures all three axes at up to 32 Hz.
Engineering expertise
Gill was founded in Lymington in 1985 and was amongst the first to commercialise ultrasonic wind measurement, with the same measurement principle now used across wind, marine, aviation and research.
Built for the access problem
No moving parts to seize, 316 stainless and IP66 on the WindObserver range, heating options and icing tested to MIL-STD-810F, for sensors that need a crane to reach.
The whole asset, not just the wind
Solar irradiance, temperature, humidity, pressure and rainfall, alongside oil debris, level and position sensing for the machinery inside the nacelle.
Designed to integrate
Modbus, SDI-12, RS422, RS485 and NMEA 0183, with analogue, Pt100 and contact-closure inputs where existing site instruments have to join the same station.
Evidence when the yield is questioned
Independent UKAS-accredited calibration across six parameters, for equipment from any manufacturer, so a whole site schedule can sit with one laboratory.
Renewable energy application notes
9 numbered application notes for this sector. Each is the original engineering document, with its PDF.
- Application note AN0065Oil debris monitoring for renewable energy drivetrains
- Application note AN0064Early warning of stator wedge failure in wind turbine generators
- Application note AN0003WindMaster for wind turbine site assessment
- Application note AN0005WO WS for Wind Turbine control
- Application note AN0024MaxiMet & MetPak monitoring at Solar Farms
- Application note AN0035MaxiMet provides measurements to support a solar car race
- Application note AN0036WindSonic used with Solar Tracking Farms
- Application note AN0041Bioethanol process from Pannonia Ethanol in Hungary monitored by MaxiMet
- Application note AN0050Remote data collection – Meteor Communications
Renewable measurement questions, from resource campaign to operating record
Nacelle-mounted sensors feed yaw and pitch control, so accuracy close to the datum matters more than top-end range. The WindObserver 75 states a turbine-control accuracy of 1 percent within 25 degrees of the datum and 1 degree on direction, in a heated 316 stainless open head.
A 2-axis sensor gives horizontal wind speed and direction. A 3-axis sensor adds the vertical component, which is what turbulence intensity, flow inclination and wake analysis depend on.
The WindMaster Pro measures all three axes at up to 32 Hz across 0 to 65 m/s.
They have no rotating element to freeze, which is the main failure mode of a cup and vane sensor. Heated models keep the transducer paths clear. The WindObserver range is icing tested to MIL-STD-810F and operates from -55 to +70 degrees C with heating.
It reports a lower wind speed than reality, so the turbine yaws late or derates. The loss is continuous and invisible, because the control system has no way to know the reading is wrong.
By measuring wind speed at more than one height on the same mast and comparing them. Two levels give a shear exponent, three or more give a profile.
MetConnect separates sensors by height in line with WMO recommendations, which is the reason to choose it over a compact single-housing station.
Pitch and yaw actuators cycle continuously across a twenty-year life. A contacting position sensor wears. The Blade range is non-contact inductive, in linear and rotary formats, with no wearing parts in the measurement.
Typically hub-height wind speed and direction, wind at two or more lower levels for the shear profile, turbulence intensity, and temperature, humidity and pressure for air density. Rainfall and icing conditions are often added.
With a solar radiation sensor sited to represent the array. The MaxiMet GMX301 measures solar radiation only, 0 to 1600 W per square metre. The GMX501 and GMX551 add wind, temperature, humidity and pressure, and the GMX551 adds rainfall.
Rarely for control, sometimes for reference. Wind varies measurably across a site with terrain and wake, which is the entire reason nacelle sensors exist alongside the met mast.
Ambient temperature, humidity and airflow at the container, because battery ratings and thermal management both derate with them. A compact station or a MetConnect handles it.
Vibration monitoring catches damage once it is developed. Wear particles appear in the oil earlier. WearDetect monitors lubricating oil for ferrous debris, which moves the question from run hours to what is actually wearing.
Most take Modbus or a serial input. The WindObserver range outputs RS422 and RS485 at 1200 to 38400 baud with a Modbus RTU variant available. MetConnect adds SDI-12 v1.3, NMEA 0183 and Modbus in RTU and ASCII, plus analogue, Pt100 and contact-closure inputs.
MaxiMet is compact and all-in-one: one housing, one cable, one output string. MetConnect separates the sensors so they can sit at different heights, and accepts third-party analogue, Pt100 and contact-closure inputs.
Yes. The WindObserver range is 316 stainless and IP66. Lloyd’s Register Type Approval is held on the WindObserver 65, 70, 75, 90 and II, ABS Product Design Assessment on the II only, and the WindObserver IS is certified to ATEX, IECEx and UKEX for hazardous areas on offshore structures.
Intervals are set by the operator and by whatever the measurement is used to argue. Where a reading supports a power curve or an availability warranty, annual traceable calibration is common.
Labcal is UKAS-accredited to ISO/IEC 17025:2017 and calibrates air velocity, temperature, humidity, pressure, and gas and liquid flow.
Six: gas and air flow, air velocity, liquid flow, pressure, temperature and humidity. Labcal, Gill Group’s independent UKAS-accredited calibration laboratory (Lab 0625), calibrates equipment from any manufacturer, not only equipment supplied by Gill.
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