The yield assumption is made
years before the first unit of generation
Three-axis wind measurement, multi-level masts and air density for pre-construction resource campaigns, with the calibration record a financing decision can be reviewed against.
A campaign that under-measures is discovered years too late
A resource campaign produces one number that everything downstream relies on. The energy yield assumption sets the financing, the turbine selection and the warranty position, and it is fixed long before anything is built.
The error in that number is rarely a dramatic failure. It is a mast that was slightly sheltered, a sensor that iced through three weeks of February, or a turbulence figure taken from a class of instrument that cannot resolve it. None of those announce themselves in the data.
By the time the site is generating, the campaign is history and the shortfall is a commercial argument between parties who each have their own view of what was measured.
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
Shear, turbulence and air density are three separate measurements
Hub-height wind speed is the headline, but it is not the whole assumption. Shear across the rotor decides how much of the wind the machine actually sees, and it changes with terrain, surface roughness and atmospheric stability through the day.
Turbulence intensity drives the loads the turbine is certified against, and it is the figure most often taken from an instrument chosen for wind speed alone. A cup anemometer averages away the variation that a turbulence figure is supposed to describe.
Air density converts wind speed into power, and it moves with temperature and pressure across a season. Measuring it on site rather than assuming a standard value is what separates a yield figure from an estimate.
The campaign also has to survive. An upland mast is visited rarely and at cost, so an instrument that keeps reporting through icing is worth more than one with a better bench figure.
Turbulence needs the vertical component
Turbulence intensity and flow inclination are three dimensional quantities. A 2-axis anemometer measures the horizontal vector and cannot resolve the vertical component that carries much of the information.
WindMaster provides 3-axis measurement at 20 Hz with options up to 32 Hz, and WindMaster Pro measures 0 to 65 m/s at 32 Hz in a stainless steel head with a PRT. Where the campaign supports a research programme, the Research range provides 50 Hz and 100 Hz output at 14-bit resolution.
The vertical component, measured rather than assumed
Explore wind sensorsSpecify for the winter you will not visit
A resource mast is instrumented once and then left. Access is by track, in conditions that set their own schedule, so every service visit is a cost and a risk that was designed in at specification.
Ultrasonic measurement removes the rotating element that ices and seizes, and a heated variant keeps the record continuous through the weeks that matter most to a seasonal average. MetConnect separates the sensors by height and accepts third-party, analogue and Pt100 inputs, which is what a multi-level mast needs.
One campaign, one continuous record
Compare weather stationsA yield assumption gets audited
Lenders, insurers and turbine suppliers all review the campaign data, and they ask the same questions: which instrument, sited where, calibrated when, and by whom.
That is a specification decision rather than a paperwork one. An instrument supplied with traceable calibration, and kept on an interval, turns a measurement into evidence that holds up when the project is refinanced or the warranty is tested.
Labcal is an independent UKAS-accredited laboratory operating to ISO/IEC 17025:2017, and it calibrates equipment from any manufacturer, which matters on a mast carrying instruments from three suppliers.
What a resource campaign carries
Three-axis wind measurement for turbulence and shear, multi-parameter stations for air density, and the accredited calibration behind both.
Wind measurement
WindMaster
3-axis ultrasonic anemometer
Three-axis measurement for turbulence intensity, flow inclination and shear, where the vertical component is part of the answer rather than an assumption.
Research range
50 Hz and 100 Hz 3-axis anemometers
Where the campaign supports a research programme or a flux measurement alongside the resource record, and the sampling rate has to resolve the structure of the flow.
WindSonic
Lightweight 2-axis ultrasonic anemometer
The practical choice for the secondary measurement levels on a mast, where horizontal speed and direction are what the shear profile needs.
Air density and site conditions
MetConnect
Separable sensors for WMO-compliant siting
A multi-level mast needs its sensors separated by height rather than stacked in one housing, and it usually needs to bring third-party instruments into the same station.
MaxiMet
All-in-one weather station, no moving parts
Where the requirement is one unit, one cable and one output string for the supporting meteorological record beside the primary wind measurement.
TruMet PW100
Infrared optical rain gauge
A solid-state alternative to the tipping bucket on a mast that nobody will visit between commissioning and decommissioning.
Where resource measurement does the work
Pre-construction campaigns
Multi-level masts on upland and coastal sites, measuring the shear and turbulence the yield model is built on.
Existing sites, new machines
Measuring what the site actually delivers before committing to a larger rotor on the same ground.
Resource and co-location
Wind and meteorological measurement alongside irradiance where a hybrid site shares one grid connection.
Met masts and platforms
Exposed installations where salt, icing and access all argue against a mechanical sensor.
Financing and refinancing
Campaigns whose data will be read by lenders and insurers years after the instruments came down.
Flux and boundary layer
Sites where the resource campaign runs alongside atmospheric measurement at 50 Hz or 100 Hz.
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.
For a resource campaign that includes anemometers, Pitot tubes, thermal probes, pressure instruments, temperature and humidity probes and data loggers, a single accredited laboratory keeps a mixed mast on one traceable schedule.
Gas meters · Mass flow controllers · Dispensing systems
Anemometers · Pitot tubes · Thermal probes
Flow meters and sensors · Process control equipment
Gauges · Transducers · Manometers · Transmitters
Thermometers · Probes · Thermocouples · Data loggers
Hygrometers · Probes · Transmitters
Getting a season of data off the mast
A resource campaign produces a continuous record that has to arrive intact, month after month, from a location with no mains power and no one on site.
Gill supports environmental monitoring, industrial sensing, embedded electronics and systems integration, so developers, consultants and met mast contractors can bring measurement into loggers, telemetry and the campaign database.
Whether the requirement is SDI-12 into a low-power logger, Modbus into a site system, or a digital output feeding a research acquisition chain, Gill engineers can support integration from specification through commissioning.
Outputs and options
- SDI-12 & serial : Low-power loggers on remote masts
- Modbus RTU : Site systems and SCADA
- Analogue : Existing logger channels
- Traceable calibration : So the record holds up on review
What the specification looks like in practice
The vertical component is measured
Three-axis ultrasonic measurement resolves turbulence intensity and flow inclination rather than averaging them away, which is what a loads assessment actually needs.
Rate to match the question
WindMaster provides 20 Hz with options up to 32 Hz, and the Research range provides 50 Hz and 100 Hz at 14-bit resolution.
Nothing rotates, so nothing seizes
There is no rotating sensing element to ice, foul, wear or seize, which is the failure mode that lets a campaign record drift quietly rather than fail obviously.
Sited the way the standard expects
MetConnect separates the sensors by height and accepts third-party, analogue and Pt100 inputs, so a multi-level mast can be built the way the siting guidance describes.
Built for a season alone on a hill
Heated variants keep the record continuous through the icing weeks that carry the most weight in a seasonal average.
Evidence when the project is refinanced
Independent UKAS-accredited calibration across six parameters, for equipment from any manufacturer, so a mixed mast sits on one traceable schedule.
Questions about resource measurement
Turbulence intensity and flow inclination are three dimensional quantities. A 2-axis instrument measures the horizontal vector only, so the vertical component that carries much of the turbulence information is not resolved.
WindMaster provides 3-axis measurement at 20 Hz with options up to 32 Hz. WindMaster Pro measures 0 to 65 m/s at 32 Hz.
It depends what the data supports. WindMaster provides 20 Hz with options up to 32 Hz, which suits turbulence and shear for a resource campaign. Where the site also supports a research or flux programme, the Research range provides 50 Hz and 100 Hz.
R3-50 and HS-50 operate at 50 Hz, and R3-100 and HS-100 at 100 Hz, all at 14-bit resolution.
From temperature and pressure measured on site rather than assumed. MetConnect and MaxiMet both provide temperature and pressure alongside the wind measurement, and MetConnect allows those sensors to be separated by height.
Heated variants are available across the range, and WindObserver is heated 316 stainless tested to MIL-STD-810F for icing. The relevant point for a campaign is that a stopped cup anemometer reports calm rather than reporting a fault.
Yes. Labcal is an independent UKAS-accredited calibration laboratory, Lab 0625, operating to ISO/IEC 17025:2017, and it calibrates equipment from any manufacturer across gas and air flow, air velocity, liquid flow, pressure, temperature and humidity.
They are usually redeployed. Because the sensing elements do not wear, an instrument that came off a resource mast can be recalibrated and reused on the operating site, on a repowering campaign or on the next project.
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