Hollybush, United Kingdom
Hollybush, United Kingdom

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Branlard E.,Technical University of Denmark | Pedersen A.T.,Technical University of Denmark | Mann J.,Technical University of Denmark | Angelou N.,Technical University of Denmark | And 5 more authors.
Atmospheric Measurement Techniques | Year: 2013

The aim of this study is to experimentally demonstrate that the time-average Doppler spectrum of a continuous-wave (cw) lidar is proportional to the probability density function of the line-of-sight velocities. This would open the possibility of using cw lidars for the determination of the second-order atmospheric turbulence statistics. An atmospheric field campaign and a wind tunnel experiment are carried out to show that the use of an average Doppler spectrum instead of a time series of velocities determined from individual Doppler spectra significantly reduces the differences with the standard deviation measured using ordinary anemometers, such as ultra-sonic anemometers or hotwires. The proposed method essentially removes the spatial averaging effect intrinsic to the cw lidar systems. © 2012 Author(s).


Smith M.,Zephir Ltd | Harris M.,Zephir Ltd | Medley J.,Zephir Ltd | Slinger C.,Zephir Ltd
Energy Procedia | Year: 2014

Lidar (light detection and ranging) technology allows remote sensing and measurement of the wind field at ranges from 10 m up to 300 m upstream of a turbine. These lidar measurements can facilitate determination of turbine performance, optimisation of energy capture, protection against extreme gust events and minimization of structural fatigue loading. This paper describes some of the system-driven requirements for such lidar systems and gives a retrospective view of the resulting technical developments - developments that now permit capable, accurate, reliable and economical turbine-mounted lidar systems to be realised. Example turbine performance measurement results from various lidar-on-turbine trials will be presented. © 2014 Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.


Mikkelsen T.,Technical University of Denmark | Angelou N.,Technical University of Denmark | Hansen K.,Technical University of Denmark | Sjoholm M.,Technical University of Denmark | And 6 more authors.
Wind Energy | Year: 2013

A field test with a continuous wave wind lidar (ZephIR) installed in the rotating spinner of a wind turbine for unimpeded preview measurements of the upwind approaching wind conditions is described. The experimental setup with the wind lidar on the tip of the rotating spinner of a large 80 m rotor diameter, 59 m hub height 2.3 MW wind turbine (Vestas NM80), located at Tjæreborg Enge in western Denmark is presented. Preview wind data at two selected upwind measurement distances, acquired during two measurement periods of different wind speed and atmospheric stability conditions, are analyzed. The lidar-measured speed, shear and direction of the wind field previewed in front of the turbine are compared with reference measurements from an adjacent met mast and also with the speed and direction measurements on top of the nacelle behind the rotor plane used by the wind turbine itself. Yaw alignment of the wind turbine based on the spinner lidar measurements is compared with wind direction measurements from both the nearby reference met mast and the turbine's own yaw alignment wind vane. Furthermore, the ability to detect vertical wind shear and vertical direction veer in the inflow, through the analysis of the spinner lidar data, is investigated. Finally, the potential for enhancing turbine control and performance based on wind lidar preview measurements in combination with feed-forward enabled turbine controllers is discussed. Copyright © 2012 John Wiley & Sons, Ltd.


Pedersen A.T.,Technical University of Denmark | Montes B.F.,LM Wind Power | Pedersen J.E.,NKT Photonics A S | Harris M.,ZephIR Ltd. | Mikkelsen T.,Technical University of Denmark
European Wind Energy Conference and Exhibition 2012, EWEC 2012 | Year: 2012

A short-range continuous-wave coherent laser radar (lidar) has been tested in a highperformance wind tunnel for possible use as a standard component in wind tunnels. The lidar was tested in a low as well as a high speed regime ranging from 5-35 m/s and 40-75 m/s, respectively. In both low and high-speed regimes very good correlation with reference measurements was found. Furthermore different staring directions were tested and taking a simple geometrical correction into account very good correlation was again found. These measurements all demonstrate the high accuracy of the lidar and indicate a possible future for short range lidars as a complement to LDA and other standard equipment in wind tunnels.


Barker W.,Natural Power Consultants Ltd. | Pitter M.,ZephIR Ltd. | Burin Des Roziers E.,ZephIR Ltd. | Harris M.,ZephIR Ltd. | Scullion R.,ZephIR Ltd.
European Wind Energy Conference and Exhibition 2012, EWEC 2012 | Year: 2012

A significant body of work has been amassed in support of the ability of lidar systems to accurately measure wind speed for wind resource assessment. Lidar measurements at heights significantly greater than those achievable with industry-standard mast anemometry enable reduction of project uncertainties through direct measurement of resource at hub height and reduction of uncertainty in measured shear profiles. Measurement of turbulence intensity (TI) at hub height also plays a role in wind resource assessment methodologies, site classification and turbine selection studies. Presented are the results of a comparison of TI measurements from ZephIR 300 and an IEC compliant 91.5m anemometer mast. The data was collected over more than 5000 hours of operation at the U.K.'s only dedicated lidar and sodar test site, operated by Natural Power in Worcestershire. Turbulence intensity measured by ZephIR 300 at typical turbine hub height is shown to be in good agreement with that measured by industry-standard anemometry. This is maintained across the wind speed and turbulence intensity ranges encountered during the test period over a full calendar year. Maximum variation between ZephIR and mast mean TI values of less than 15% is observed with variation in atmospheric stability conditions and measurement height for a typical one month deployment across the year. This is of the order of reported accuracy for industry-standard cup anemometry in the measurement of wind speed variance and demonstrates the ability of ZephIR 300 to measure TI values in flat terrain to an accuracy suitable for use in wind energy applications.


Barker W.,Natural Power Consultants Ltd. | Slinger C.,ZephIR Ltd. | Pitter M.,ZephIR Ltd. | Burin Des Roziers E.,ZephIR Ltd. | And 2 more authors.
European Wind Energy Conference and Exhibition, EWEC 2013 | Year: 2013

A significant body of work has been produced in support of the ability of lidar systems to accurately measure wind speed for wind resource assessment. Lidar measurements at heights significantly greater than those achievable with industry-standard mast anemometry enable reduction of project uncertainties through direct measurement of resource at hub height and reduction of uncertainty in measured shear profiles. Measurement of turbulence intensity (TI) at hub height plays a role in wind resource assessment through the estimation of energy losses due to turbine wakes and is also a key component of site classification and turbine selection studies. In the work presented here deviation in TI measurements observed at the ZephIR Ltd. IEC compliant tall mast test facility are considered in the context of a typical wind farm Energy Yield Analysis (EYA) methodology to determine the associated deviation in net Annual Energy Production (AEP) for calculations based on data from ZephIR 300 and the mast. For a typical turbine separation, wind speed distribution and direction distribution the deviation in net AEP with observed deviation in measured TI is small compared to that associated with the uncertainty attributed to other inputs to the EYA methodology. Analysis of the wake model implemented suggests that the results obtained should hold for general turbine layouts within the scope of the model. This result is considered as evidence of the ability of ZephIR 300 to measure TI values in non-complex terrain to an accuracy suitable for use in a typical wind farm energy yield analysis.


Slinger C.,ZephIR Ltd. | Leak M.,ZephIR Ltd. | Pitter M.,ZephIR Ltd. | Harris M.,ZephIR Ltd.
European Wind Energy Conference and Exhibition, EWEC 2013 | Year: 2013

Power curves are an important way of measuring turbine performance. IEC standard 61400-12- 1 describes procedures to measure absolute power curves using ground-based metmasts. However, in many situations, it is more convenient and efficient to use turbine-mounted lidars to measure power curves. This arrangement ensures measurement of wind incident on the rotor irrespective of the wind direction, avoids the considerable difficulties associated with offshore metmast deployment, allows rapid measurement at multiple upwind ranges from the turbine and permits straightforward measurement of both hub height and rotor equivalent wind speeds. A circular scan lidar also permits a sampling of the wind field around the full rotor disk, and wake visualisation is also possible. Power curves derived from these measurements can allow turbine performance to be measured and compared pre- And post- intervention / adjustment / maintenance. The lidar measurements also allow calibration of other turbine instrumentation and permitting accurate measurement of yaw alignment and the investigation of the impact of atmospheric effects such as vertical wind shear and turbulence. This paper presents the results of measurements from a nacelle-mounted, circular scanning continuous-wave ZephIR lidar, operating on a 2 MW onshore, horizontal axis turbine in Jutland, from January to April 2012. Lidar measurements at ranges from 10 m, 30 m, 50 m, 100 m and 180 m were taken (corresponding to ranges from 0.14 D to 2.5 D). Hub height wind speeds, wind yaw direction and vertical wind shear time series were obtained from these measurements. The measurements helped identify a consistent 14 to 16 degree yaw misalignment of the turbine. The pre and post yaw wind vane sensor calibration power curves are compared in the paper. The influence on power curves of lidar-measured high and low vertical wind shear, high and low atmospheric turbulence are also shown. By examining the wind speed at various ranges upwind of the turbine, the effects of turbine blade induction were also observed and measured. Turbulence and wind shear are found to have significant effects on the power curves. The measurements confirm that turbine-mounted, circular scan, continuous wave lidar can be a useful tool for turbine characterisation and instrumentation calibration. Measurement of turbine power curves, particularly offshore, is an important application area for turbine-mounted lidars.


Grant
Agency: GTR | Branch: Innovate UK | Program: | Phase: Collaborative Research & Development | Award Amount: 696.98K | Year: 2015

WinTIL will develop the technology for the first generation of LIDAR systems suitable for integration into wind turbines, in order to provide advance information about the incident wind field across the entire rotor area. This data can then be used by turbine control systems to minimise fatigue loads and to optimise energy extraction. Reductions in fatigue loads on turbines and components will enable optimised service intervals and extend service life for onshore and offshore turbines. More efficient, safer and more reliable energy generation will reduce costs and improve public perceptions of wind energy. It is currently impossible to use lidars in this way due to technology limitations and the need for systems to be cheaper, more reliable and compact. WinTIL will integrate continuous-wave (CW) lidar into the turbine and reduce system complexity through innovations such as automatic scanning, optimised optical transceivers and data processing algorithms. The WinTIL consortium has experience of incorporating current wind lidars into turbines for research purposes, and is ideally placed to move these concepts to a market-ready design.


Trademark
Zephir Ltd | Date: 2016-03-30

Anemometers; Laser anemometers; Laser doppler anemometers; Ground based laser anemometers; Vehicle mountable laser anemometers; Buoy mountable laser anemometers; Ship mountable laser anemometers; Aircraft mountable laser anemometers; Airborne laser anemometers; Laser anemometers for true air-speed measurements; Laser anemometers for air turbulence measurements; Laser anemometers for measuring wind speed in a wind tunnel; Wind turbine mountable laser anemometers; Optical fibre based laser anemometers; Laser doppler velocimeters; Laser radars; Laser based wind speed measurement apparatus; Apparatus for measuring wind speed using infra-red radiation; Parts and fittings for all of the aforesaid goods. Maintaining and servicing anemometers, radars, velocimeters, laser based wind speed measurement apparatus, apparatus for measuring wind speed using infra-red radiation. Wind speed measurement services; Wind speed measurement services using laser anemometers; Wind speed measurement services using optical fibre based laser anemometers; Laser anemometry services; Laser doppler anemometry services; Ground based laser anemometers services; Vehicle mounted laser anemometers services; Buoy mounted laser anemometers services; Ship mounted laser anemometers services; Wind turbine mounted laser anemometers services; Aircraft mounted laser anemometers services; Laser anemometers services for measuring wind speed in a wind tunnel; Measuring of air turbulence using laser anemometers; Measuring true airspeed using laser anemometers; Laser doppler velocimetry services; Lidar services for acquiring wind speed measurements; Wind speed measurement services using lasers; Wind speed measurement services using apparatus incorporating a source of infra-red radiation.


Grant
Agency: GTR | Branch: Innovate UK | Program: | Phase: Small Business Research Initiative | Award Amount: 29.71K | Year: 2016

Wind Turbine Integrated Lidar – GO LIVE; ‘WinTIL – GO LIVE’. With existing funding from Innovate UK under the WinTIL project, Zephir Ltd. has successfully designed a wind turbine hub-mounted wind speed sensor (ZPINNER) based on Continuous Wave (CW) lidar technology that can be used to reduce turbine loading, optimise turbine performance and increase energy generation. By doing so it reduces the cost of wind energy, reduces carbon emissions and increases the security of energy supply hence addressing the energy trilemma (www.worldenergy.org/work-programme/strategic-insight/assessment-of-energy-climate-change-policy/) and satisfies Innovate UK requirements in the Energy Catalyst funding competition. Over the last 10 years, Zephir Ltd. has become a leading global wind lidar innovator and manufacturer, exporting ~80% of all it produces to more than 50 countries worldwide. This step-change innovation, based on ZephIR’s unique core CW lidar technology, aims to deploy the First of its Kind in a real-world, user-facing project offering several UK-based SMEs within the supply chain a significant route to market. The specific business opportunity is the mass adoption of the ZPINNER wind sensor on wind turbines. There are ~300,000 turbines operating globally as an existing addressable market for ZPINNER and in addition there are ~15,000-20,000 new turbines installed every year. While WinTIL has taken core research from fundamental scientific principles and produced a proof of concept demonstrator (TRL 7) which has proven the technology, it has not overcome all the barriers to entry to bridge the chasm from early innovators to early adopters and on to the mass majority in the product life cycle (TRL 8 & 9). There are three significant barriers to overcome to drive mass adoption and uptake of the ZPINNER that will be addressed by ‘WinTIL – GO LIVE’: 1.) First Of A Kind Deployment (FOAK). While ZPINNER has been proven conceptually on an individual turbine, the value proposition is not evidenced to the level required by the market to perceive a low enough risk to adopt across an entire wind farm. The market is waiting for ‘others’ to adopt the technology before it commits. There is a need to accelerate a First Of A Kind deployment of the technology in a significant enough volume that produces the evidence and demonstrates the value proposition to secure volume sales. Funding this stage of New Product Introduction is currently the most significant barrier to market adoption. 2.) Design for Manufacture. The ZPINNER product design is suitable for small scale manufacture but would benefit from additional improvements to enable it to be manufactured in volume in a cost effective and efficient way to the repeatable high product quality demanded. 3.) UK Supply chain investment. Zephir Ltd. is currently organised to manufacture ~100 lidar units per year. Zephir Ltd. has initiated the build / investment in a larger facility to provide increased production capacity but requires assistance for tooling, calibration and test equipment within the ZPINNER manufacturing line. Investment in UK SME suppliers in our supply chain will give the support required for delivering against the significant opportunity that a FOAK deployment will unlock and the option to onshore currently offshored key ZPINNER components.

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