Operator of UK wind farms selects Sodar to better plan operations

One of the UK’s biggest renewable energy companies is using Second Wind’s Triton Sonic Wind Profiler to evaluate wind farm sites and position wind turbines for maximum productivity and profitability. Triton, a remote sensing system, uses sodar (sound detection and ranging) technology to measure wind at greater heights than the previous tower-based standard. Triton’s compact form, ease of deployment, low power requirements and reliability give wind power companies the versatility to streamline wind-farm developments.

Sodar will let the company forecast more confidently annual energy production by measuring wind at the heights covering the full rotor sweep of a commercial turbine, which yields the most accurate portrait of wind resources on a particular site.

“Used in conjunction with tower-mounted sensors, we expect the wind data will let us obtain better project financing terms,” says RWE npower renewables analyst Annabel Gammidge.

“Beyond project financing, we see the portability of the Triton system as an advantage. We can move them around our site to obtain a stronger characterization of the wind, rather than being stuck with the data from one hard-to-relocate tower,” says Gammidge.

Before deploying its first Sodar unit on a wind measurement campaign, RWE tested the unit against data collected from a 60-m met tower in northern England. The Triton and met tower data correlated well with a correlation coefficient of 0.986. There was a differential in average wind speed at 60 meters of less than 0.9%, and the Triton system demonstrated a reliability of 99.8%. The Triton performed as well as promised so RWE was able to move it to a wind farm development site in Wales that was under evaluation.
RWE npower renewables
www.npower-renewables.com
www.rweinnogy.com.

Second Wind
www.secondwind.com

Sodar sensing for hub-height wind used more widely

Remote wind sensing is winning broader acceptance as wind farm developers use it to measure wind characteristics such as in-flow angle and turbulence. Investors are also putting confidence in remote sensing data. This message emerged from the annual Triton User Group sponsored by wind technology company and sodar manufacturer Second Wind.

Independent engineers, consultants, and Second Wind Triton Sonic Wind Profiler customers envisioned a broader role for remote sensing (sodar) in their comments at the Triton User Group and workshop sessions held prior to the American Wind Energy Association’s annual conference. Users agree that remote sensing is a logical option as the wind industry searches for ways to reduce the uncertainty of evaluating and financing wind-power projects.

Second Wind’s Triton, an advanced remote sensing system, uses sodar (sound detection and ranging) to measure wind speed and direction. The company says measuring wind speeds at the turbine hub height and higher lets the units reduce uncertainty in annual energy production (AEP) forecasts. Easy to install (two men and a pickup) and with autonomous operation, these sodar unit are used throughout the wind industry, alone or with met towers, to streamline wind-farm development and to improve their operations. The panel included representatives of AWS Truepower, Chinook Wind, DNV Renewables, and GL Garrad Hassan.

A concern echoed by multiple panelists is that the portability of the remote sensors might encourage wind prospectors to shorten measurement campaigns. “We cannot complete a wind-resource assessment in a week!” said one panelist. His message was reinforced by another assertion that “Short-term measurement campaigns won’t reduce uncertainty but can lead to incorrect conclusions.”

Evaluating complex terrain was a recurring subject. More than half of the users at one session said they are using sodar on topographically complex sites and finding that the results correlate well with conventional tower-mounted instruments.

Throughout the conference, discussions focused on the importance of reducing uncertainty in wind resource assessments, and the increasing role that remote sensing systems play in reducing uncertainty. During a panel discussion on the future of resource assessment, Gisela Kroess, Managing Director, Project & Commodity Finance, UniCredit Bank AG, said the main source of the widely reported 10% underperformance of North American wind farms in recent years is due to overestimating wind speeds, a consequence of using flawed methods of measurement and extrapolation.

Second Wind
www.secondwind.com

Triton sonic wind profiler makes its way to the UK

One of the UK’s biggest renewable energy companies is using Second Wind’s Triton Sonic Wind Profiler to evaluate wind farm sites and position wind turbines for maximum productivity and profitability.

RWE npower renewables operates 23 wind farms and 18 hydroelectric plants in the UK. Its parent company, RWE Innogy, is one of Europe’s leading energy companies, supplying electricity to 16 million customers. RWE npower renewables uses two Triton units to profile wind speed, direction, shear, and other variables at existing and prospective wind power sites. Using the Tritons, RWE npower renewables can more confidently forecast annual energy production (AEP) by measuring wind at the heights covering the full rotor sweep of a commercial turbine, which yields the most accurate portrait of wind resources on a particular site.

“We’re using Triton because we’re confident that the new generation of remote sensing technology will reduce the uncertainty in our wind resource assessment,” says Annabel Gammidge, Regional Analytical and Monitoring Strategy Manager at RWE npower renewables. “Used in conjunction with tower-mounted sensors, we expect that the Triton data will allow us to obtain better project financing terms.”

Triton is a remote sensing system that uses sodar (sound detection and ranging) technology to measure wind at greater heights than the previous tower-based standard. Triton’s compact form, ease of deployment, low power requirements and high reliability give wind power companies the versatility to streamline the wind farm development process.

“Beyond the project financing applications, we see the portability of the Triton system as an advantage. We can move Tritons around our site to obtain a stronger characterization of the wind all over the site, rather than being stuck with the data from one hard-to-relocate tower,” Gammidge says.

Before deploying its first Triton on a wind measurement campaign, RWE npower renewables tested the unit against data collected from a 60-meter met tower in northern England. The Triton and met tower data correlated extremely well with a correlation coefficient of 0.986. There was a differential in average wind speed at 60 meters of less than .9%, and the Triton system demonstrated a reliability of 99.8%. The Triton performed as well as promised so RWE npower renewables was able to move it to a wind farm development site in Wales that was under evaluation.

Second Wind www.secondwind.com

 

 

University plans to put West Virginia surface mine sites to wind use

Triton Sonic Wind Profiler and SkyServe wind data service provide accurate, versatile platform for documenting wind resources in ‘brownfield’ areas too rugged and isolated for met towers.
Coal mined from West Virginia’s mountains has powered this country for decades, and now Second Wind’s wind data collection equipment is helping former and active coal mining sites find second energy-producing lives as homes for wind farms and other renewable energy facilities. Marshall University’s Center for Environmental, Geotechnical and Applied Sciences (CEGAS) is using Second Wind Triton Sonic Wind Profiler and SkyServe satellite wind data service to evaluate the wind energy potential on former surface mine sites. Working with the West Virginia Division of Energy and the Appalachian Regional Commission, CEGAS has used the Second Wind technology to evaluate two former surface mine sites around the state, and is presently evaluating a third. The university’s goal is to help surface mine property owners determine whether they can make strip-mined land productive again by converting it to renewable energy uses, with wind being one of the primary energy resources.

The CEGAS staff chose Triton because, they said, it reliably measures wind at turbine hub heights of 80 meters and higher, and its mobility allows using it at hard-to-access sites. CEGAS also uses SkyServe to collect data from the Triton, eliminating the need to travel to sites and collect data manually. As part of deploying the Triton, CEGAS confirmed its performance with multiple three-week studies, correlating Triton data with data from nearby met towers. That gave the university a versatile, cost-effective alternative to met towers, which would have been difficult and expensive to erect on the surface mine sites, according to CEGAS Environmental Manager George Carico.

“West Virginia is a rural state and travel can be tough,” he said “Triton is super easy to operate and has great mobility. We take it to remote surface mine locations on a trailer pulled by a four-wheel drive vehicle and have it working within a few hours. Some of these sites are miles off the electric grid, so Triton’s solar panels and deep-cycle battery units save us from setting up and refueling remote generators. SkyServe also makes the system easy to use because we can retrieve data from our Triton remotely, export it straight into spreadsheets and consolidate it with data from Windographer and AWS Truepower Wind. It puts everything we need right at our fingertips.”

Triton, an advanced remote sensing system, uses sodar (sound detection and ranging) technology to measure wind in the areas that most affect a wind turbine’s performance. By measuring wind speeds at the turbine rotor’s hub height and beyond, the unit reduces uncertainty in annual energy production (AEP) forecasts.

SkyServe Satellite Wind Data Service is a remote communications system that lets Triton users view wind data in near-real-time. SkyServe uploads wind data every 10 minutes, via Globalstar satellite, to a secure web server. SkyServe adds a GPS location and time stamp to all data as it’s recorded, eliminating the inaccuracy or guesswork that can accompany remote data without GPS information. Its suite of reporting tools translates wind data into information.

“Marshall University’s work on the reuse of surface mines underscores an important fact in the wind power industry, which is: you have to go where the wind is and sometimes it’s in a challenging location,” said Second Wind CEO Larry Letteney.

Second Wind LLC
www.secondwind.com

Wind prospecting in Poland

As Poland’s wind energy industry accelerates its new project development initiatives to meet European Union mandates and exploit the country’s promising wind resources, project developers are being offered expanded access to technology that will help drive the development process. Poland has vast onshore and offshore wind resources and is doubling its wind power capacity every year. Spurred by its own economic growth and European Union renewable energy mandates, Poland is predicted to expand its wind power twentyfold by 2020.

Renewable energy consulting firm Wind Prospect will be taking delivery of two Second Wind Triton Sonic Wind Profilers this month to provide developers in Poland’s growing wind power market with fast, economical access to hub-height wind measurements.

Wind Prospect will make Second Wind’s Triton sodar system available through rental contracts. The rental option enables developers to collect wind data using the wind industry’s market-leading remote sensing technology under flexible financing terms. Wind Prospect will initially be using these two Tritons to support five wind development projects in Poland.

“Using Second Wind’s Triton, we are able to offer developers a simple, reliable and cost-effective means of collecting data at hub height either to supplement data from an on-site mast or for early stage site prospecting,” says Gabriel Amiel, Commercial Manager for Wind Prospect. “In particular, many wind developers are seeking to increase the value of their projects by measuring wind speeds at 120 meters or more for a few months and correlating this with the data from their mast. A Triton is the ideal technology for this.”

“Wind Prospect is filling an important niche in Poland’s wind energy market by providing Tritons to developers through rental agreements,” says Jason Wood, Second Wind’s director of European sales. “Wind developers have to figure their budgets very closely in the prospecting and assessment phases, and there sometimes isn’t room for equipment purchases. Renting is the perfect solution.”

Second Wind www.secondwind.com

 

Community program gives access to resource assessment

A manufacturer of wind measurement systems has developed a turn-key community wind information service to provide community wind project developers with analysis of wind power potential. Second Wind says its program will fuel the growth of community-scale wind power projects. The Community Wind Information Service uses leading-edge wind measurement technology to provide comprehensive wind resource analyses to individuals and groups who are considering wind turbines on sites such as farms, industrial facilities, landfills, schools, wastewater treatment plants, and community lands.

The service will enable community wind developers to decide quickly and cost-effectively whether the wind resource at their site will make their proposed wind power project economically viable. The process begins with Second Wind deploying a Triton Sonic Wind Profiler to conduct a wind measurement campaign. Second Wind then analyzes the Triton data and other wind information sources to produce a Wind Information Report. The report includes detailed wind resource data, energy estimates, and capacity factors of turbines that the customer is considering. With minimal environmental impact, few permitting requirements, and a fast installation process, Triton can accelerate the development process. Because Triton units are easily relocated, Second Wind can evaluate multiple sites in a single community faster and at a lower cost than meteorological towers.

“Community wind project economics are very tight,” says Matthew Cumberworth, Sr., vice president wind energy at WPCS, an international design-build engineering firm that provides meteorological tower and Triton installation, maintenance, and data services to wind farm developers. “Many projects don’t have a budget for consulting and equipment purchases for site evaluation. A service like Second Wind’s can make the difference between a productive project and a project that’s shut down after a year.”

Triton is a remote sensing system that uses sodar technology to measure wind at higher heights than the previous tower-based standard. By measuring wind speeds at the turbine rotor’s hub height and beyond (up to 200 m), Triton reduces uncertainty in annual energy production (AEP) forecasts.

The Community Wind Information Service is available to municipalities, private landowners, engineering firms, or anyone developing community wind projects. It is cost-optimized for projects with small capital budgets involving low numbers of small turbines – 1 or 2 MW. The assessment period can last anywhere from 3 to 12 months, and all service options are priced under $50,000 USD.

Second Wind www.secondwind.com

Sodar measurements speed European wind-farm development

Formed in 2007 to finance the development of wind farms in Central and Eastern Europe, Continental Wind Partners (CWP) uses the Triton Sonic Wind Profiler as a part of its standard wind resource assessment practice. The developer is using advanced remote sensing (with eight Tritons) to expedite wind farm development, reduce project uncertainty and streamline project financing at sites in five Eastern European countries.

Triton is a sodar-based (sound detection and ranging) remote sensing system that measures wind at higher heights than most tower-based devices. By measuring wind speeds at the turbine rotor’s hub height and beyond (up to 200 m), the sodar unit reduces uncertainty in annual energy production forecasts. Its ease of deployment also streamlines wind-farm developments. The design have been in commercial use since April 2008 with over 200 installed worldwide.

“Although met-tower data remains a key part of wind project financing, remote sensing is becoming more necessary to reduce uncertainty by measuring hub height wind conditions,” says Konrad Gorzkowski, Wind & Site Engineer at CWP. “We like the unit because of its low power requirements, mobility, and data reliability.”

CWP uses the sodar units to support its project development activities, and in doing so has accumulated nearly 100,000 hours of data in Central and Eastern Europe. On sites with existing met towers, CWP has deployed a Triton at several locations around the site to better map the available wind resources, an approach known as micro-siting. “Triton always correlates well to the met tower measurements and provides valuable information on each site’s large height shear profile,” says Maciej Baginski, Wind Measurement and GIS Specialist at PS Wind Management, CWP’s Poland-based development group.

CWP expects the sodar units to give an advantage in securing project financing. In one example, a single unit was deployed at five different locations on a greenfield site that already had a met tower. Triton measurements reduced this project’s resource uncertainty by three percent, compared with use of the met tower data alone, which directly led to a considerably higher P75 figure.

Second wind Inc.
secondwind.com

Sodar, data loggers, and sat comm solve remote-sensing problem

Realizing that managing data communications presents a problem, developer Competitive Power Ventures (CPV) brought in monitoring equipment to collect large accurate data sets for evaluating wind power potential even in remote sites. Expanding into more remote wind-site areas meant the company needed more data collection points unified by a communications network that allowed remote monitoring and management.

CPV VP and Manager of Canadian Operations for Wind Paul Wendelgass evaluated the company’s measurement strategies and recommended wind assessment equipment such as Nomad data loggers and the SkyServe satellite data service from Second Wind Inc. CPV had also previously adopted the firm’s Triton sonic wind profiler. “After evaluating our situation, we realized we needed flexible products that didn’t rely on spotty cell phone networks for communication and had an additional reporting element,” he says. “The Nomads provided a level of flexibility for adding wind vanes, temperature sensors, and barometers without additional work. The satellite service provides communication capabilities, real-time diagnostics, and when necessary, an ability to fix a problem soon after it’s detected.”

CPV’s renewable energy division is developing nearly 7,500 MW of wind power projects across North America with plans for more. For instance, the company recently began construction on a 152-MW wind farm in Woodward County, Oklahoma which is slated to go on-line later this year. Oklahoma Gas and Electric bought the first phase of the project and is delivering electricity into the grid.

“It can take up to a year of data collecting and development activity to get a site approved,” says Wendelgass. One way to maximize its investment is with the data loggers and sodar units because once they have served their purpose at one site they can easily be moved to a new destination and put to work almost immediately. SkyServe then combines real-time and historical information for a comprehensive assessment of a site’s performance. “The Triton’s compact design means we don’t need special transports or armies of people to relocate them. Using them at several sites translates into a quicker return on investment,” adds Wendelgass.

Competitive Power Ventures Holdings LLC
www.cpv.com

Second Wind
secondwind.com

Sound intelligence in the search for wind power

Reprint Info >>

The wind industry’s need for wind measurement has grown beyond the 60-m reach of standard meteorological (“met”) masts. To reduce uncertainty for wind projects that can cost anywhere from $100 million to $1 billion, the industry needs data from the entire rotor sweep that can’t be gleaned from 60, 80, or even 100-m met masts.

A 60-m met mast outfitted with sensors measures only about a quarter of the rotor sweep of a typical commercial turbine mounted on an 80-m tower. Taller masts are obtainable, but permitting and aircraft obstruction regulations make them challenging to site. And even where an 80-m mast is feasible, it only monitors the lower half of the wind powering the turbine. Is there a solution to met mast shortcomings?

Remote sensing is a credible alternative to mast-based measurements. Remote sensors are ground-based, and use sound or light to measure wind speed and direction at various heights. They can reveal the extent of wind shear events and wake effects. Developers prospecting new sites can use remote-sensing equipment to quickly identify the most promising turbine locations while eliminating marginal locations. With that intelligence, they can use fewer met masts and site them more effectively.

Beyond their height limitations, masts are firmly anchored to their location. If they’re not set up in the right area to measure the best wind on the site, it’s a cumbersome process to move them. Remote sensors, on the other hand, can be relocated in just a few hours. That makes them increasingly used for rapid wind prospecting, detailed wind resource assessments, and operations and maintenance studies.

Remote sensing

The “remote” in remote sensing refers to the separation between the devices and what they measure. Remote wind sensors operate on similar principles, whether radar, sodar, or lidar. They all emit signals of one form or another in a beam pattern. The emitted signals encounter variations in the air, reflecting back to the sensing equipment. Frequency changes from the original signals are interpreted as Doppler shifts, indicating that the sensed winds are moving towards or away from the instrument. Processing the Doppler shifts, elapsed times, and geometries of the emissions and reflections yields a profile of wind conditions.

Remote sensors used in the wind industry are based on either sodar (SOund Detection And Ranging) or lidar (LIght Detection And Ranging) technology. Radar isn’t used in wind energy applications because it can’t resolve wind speeds within a few hundred meters of the ground.

Sodar is a form of sonar, like that used for echolocation by dolphins and bats. Sodar sends audible acoustic pulses into the air, which reflect off encountered temperature differences. Microphones detect the resulting “back-scatter.” Calculating the time it takes for the sounds to travel back to the microphones yields the heights where the reflections occurred. Measuring the frequency change from the emitted pulse allows calculating wind speed towards or away from the instrument. Sending acoustic pulses in three or more different directions allows translating steeply angled wind speed measurements into horizontal wind speeds and directions over the measurement range.

Second Wind’s Triton is one example of a next generation sodar system. The Triton is built around a 36-element array of piezoelectric trans-ducers, which operate as either highly efficient speakers or microphones. In speaker mode, the array emits sonic “chirps” that reflect off an internal sound mirror and into the atmosphere. Switching to microphone mode, the arrays record echoes from the sound scattering.

The array is called “phased” because individual transducers are operated in acoustic phase with each other. Phased arrays are used in radio astronomy and other precise imaging applications, because they substitute inexpensive and efficient small transducers for more costly, larger equivalent devices. The transducers can create a better-directed beam and listening cone than a single speaker-microphone, thanks to the physics of interference patterns. Only one array is needed for three different beam directions. Triton achieves this by introducing time delays between rows of transducers, there being three-row orientations 120° apart in the hexagonal array pattern.

The U.S. Department of Energy’s National Renewable Energy Lab reports that sodar delivers accuracy comparable to tower-mounted meteorological instruments. The lab recently tested a Triton and found its wind speed and direction data correlated well to instruments mounted on meteorological towers.

“We see Triton as a valid stand-alone system for wind measurement studies,” says NREL Principal Scientist Dennis Elliott. “In addition, the sodar unit was reliable, with an uptime of more than 98%.”

The Energy Research Center / Netherlands came to a similar conclusion after comparing Triton data to data from a 100-m meteorological tower mounted with four anemometers and wind vanes at different heights. While maintaining 98.85% operational availability, the sodar unit provided data on wind speed, direction, shear, and turbulence intensity that qualified it as “a stand-alone system for wind resource assessments, especially given the industry’s tendency toward higher hub heights,” states the report.

Lidar, like sodar, measures wind speeds by processing the Doppler shifts of its emitted beams. A lidar either pulses or continuously fires a solid-state infrared laser while motorized mirrors or optical waveguides maneuver the beams. These strike particles in the air, “aerosols,” which reflect back to the source instrumentation where photosensors detected them.

In the case of lidar, the Doppler shift takes the form of a slight color change in the radiated laser light. The shift is generally not directly measurable due to light’s ultra-high frequency. Measurements are using various electronic and optical modulation and detection techniques.

Like sodar and sonar, lidar technology has been in use for years in applications other than wind power. Meteorological lidar has been used successfully to measure narrow regions of air, sometimes to distances as great as 15 km. Such systems have been built with color-tunable lasers, high-power requirements, and great expense, typically upwards of $1 million.

Lidar systems now at work in wind-energy applications use lasers and optical detectors developed for fiber-optic communications, so they are not tunable for atmospheric applications. They have limited power – typically in the hundreds of watts instead of kilowatts – giving them a range comparable to sodar: hundreds of meters instead of kilometers.

Sodar and lidar each have advantages and disadvantages. Lidar’s strong suit is response time. Light speed permits many more measurements than can be made in the round-trip time of sound waves traveling a few hundred meters. Lidar can make second-by-second wind-speed measurements, which are useful for wind turbine controls. For resource assessments, however, the high response speed possible with lidar has no particular advantage.

Sodar’s technical advantages include an inherently lower cost and power of basic transducers. These are not academic considerations. There are several sodar systems available from $50,000 to $75,000, while the lowest cost complete lidar systems carry price tags of $150,000 to $250,000. The lowest power sodar, Triton, consumes 7W on average. The lowest power lidar system is reported to be 45W. For remote applications this is a substantial difference.

For the wind industry, sodar is inherently better at making precise frequency shift measurements than the lidar technology used in wind applications. Audio frequency measurements of hundreds of parts per million is commonplace. It is difficult to make, within a percent, accurate measurements of fiber-optic laser emissions that have been Doppler shifted by wind speeds of just a few meters per second.

Both sodar and lidar have characteristics that can limit the range and reliability of their data. For example, sodar is susceptible to ambient noise in the range of its operation, especially at lower frequencies. Dry, thermally homogenous air affects sodar’s performance and it can’t compete with a hard rain. Lidar cannot work through a dense fog and its performance drops in clean air, including after rainfall where the aerosols have been washed away. Lidar can also have issues with sunlight and cloud cover.

However, anemometers and wind vanes are also prone to malfunctions and failure from rain, freezing, and dust. They perform nonlinearly in the presence of non-horizontal flow, and can’t measure inflow angles. Mast-mounted sensors are vulnerable to lightning strikes and other environmental hazards – much less of an issue with ground-mounted remote sensors. The reliability of remote sensing systems’ can rival that of the best conventional mast-based systems. And the reliability of 100 m-plus lidar or sodar is greater than extrapolations made from measurements from a 60-m mast.

Reducing uncertainty

The current political and social climate forecasts big growth for wind power. That growth will not occur, however, unless developers can convince investors that wind power is a reliable, profitable power source. There is inherent uncertainty in banking on the wind. Investors don’t like uncertainty, so it’s incumbent on developers to reduce it.

Meteorological towers don’t yield enough data. They don’t reach high enough to measure a modern turbine rotor’s full sweep, which forces developers to rely on extrapolations. There’s no reason to do that when remote sensing can provide the missing data.

Furthermore, the wind-power industry would benefit from a new equation between fixed and remote sensing. The current standard is to erect three to five masts for every remote sensor used on a site. That ratio should be reversed: three to five remote sensors for every mast. Remote sensing equipment should be the primary data gatherer. They’re just as accurate as mast-mounted sensors, gather more data, and are more cost effective, and versatile. Mast-mounted sensors’ proper role right now is providing reliable data baselines for correlating remote units.

Combining remote and fixed sensing in these roles adds up to more comprehensive wind data sets that reduce the uncertainty inherent in wind farm development. Combined, they offer wind-farm developers persuasive facts to attract investors, while offering investors an assurance of a return on their investment. WPE

-Susan Giordano/Second Wind Inc, Somerville, Mass./www.secondwind.com

Wind developer prefers sodar

Spain’s renewable energy economy is flourishing, with some regions generating as much as 82% of their power from renewable resources. Barlovento Recursos Naturales, a Spain-based international wind consultancy, has helped the country step forward in wind energy especially, using Second Wind’s remote sensing systems to assess sites in Spain and Romania. The company’s sonic sensing of wind (or sodar) measures wind speed and direction at different levels up to 200 m and more.

“Remote sensing gives us a much broader and deeper data set than we could collect with tower-mounted sensors alone,” Barlovento founder Rafael Zubiaur says. “Its accuracy provides a detailed profile of wind flow so we can forecast a site’s productivity and how factors like shear and veer may affect wind turbine performance.”

Second Wind
www.secondwind.com