1. This brochure was produced with consideration for the environment. It is printed on paper that is
100% recycled and has an FSC accreditation. Renewable energy consultants
All information correct at time of print February 2012
Technical by nature...
ONSHORE WIND SErvices
www.gl-garradhassan.com

2. Contents 2 About GL Garrad Hassan About GL Garrad Hassan
4 Services and products
6 Global credentials
1
0 Research and development
12 Technical excellence
1
4 Supporting the project developer
The acknowledged technical
1
9 Supporting the owner/ operator
2
4 Supporting the investor/ lender
2
6 Strategic and policy advice
authority on onshore wind
27 Training couses
2
7 More GL Garrad Hassan brochures
Put quite simply, GL Garrad Hassan has
advised on more onshore wind projects
around the world than any other organisa-
tion. Its experts have been leading the
technical understanding related to
generating power from wind from the outset
and this, combined with a heavy investment
in R&D, has secured its position as the
authority on wind energy.
GL Garrad Hassan’s client list boasts all of
the wind industry’s major players whether
they be developers, owners, operators,
investors, lenders or manufacturers. It also
regularly provides strategic and policy advice
THE WORLD’S LARGEST DEDICATED
to Governments, NGOs and industry bodies.
“Wind energy is no longer an eccentric
observer of the electricity industry; it
RENEWABLE ENERGY CONSULTANCY has arrived in the main stream. The
technology has changed – wind
GL Garrad Hassan is the world’s largest dedicated renewable energy consultancy, offering independent technical turbines are now the world’s largest
and engineering services, products and training to the wind, wave, tidal and solar sectors. From a network of local
offices right across the globe, its experts deliver unrivalled breadth and depth of service to clients at all stages of the
rotating machines; the owners and
renewable energy project lifecycle. manufacturers have changed – no
longer are they farmers and landowners
supplied by backyard companies; they are
A rich heritage now the same suppliers and the same
GL Garrad Hassan is the renewable energy division of the GL Group and has a rich heritage. It was created by the
customers as in conventional generation.
integration of Garrad Hassan and the GL renewables entities of Noble Denton, Helimax and WINDTEST. Each of these
organisations was at the forefront of its respective specialism and combined, they offer solutions that meet the
current and future needs of the burgeoning renewable energy industry as it becomes main stream. GL Garrad Hassan has been involved
from the outset and so has taken the
very same journey. The organisation is
now designed to provide a comprehensive
Independent advice guaranteed global service to a sophisticated
GL Garrad Hassan is a consulting company. It has no equity stake in any device or project. This rule of operation is
client base whilst drawing on the last
central to its philosophy which sets it apart from many competitors and underlines its independence. 30 years of experience, which
underpins everything that we do.”
2 3
Dr. Andrew Garrad, President

3. Services and products
World-class
Comprehensive stakeholder solutions for products
the life of the project
Project development Operational projects Investors/lenders Government/NGOs
Project development partner Asset management consulting Banks’ Engineer Market intelligence
Strategic and policy advice Performance and condition monitoring Project/portfolio due diligence Policy and regulatory studies
Training courses Fault diagnostics Company due diligence Specialist strategic studies
Operational energy assessment Construction monitoring
Feasibility Short-term forecasting Pre-construction energy assessment
WindFarmer
Constraints review Turbine inspection Turbine due diligence
Wind farm design software
Conceptual wind farm design Power performance measurements Interconnection review WindFarmer has been developed to ease
Wind mapping and energy analysis Electrical measurements Inspections and audits the design of wind farms. It maximises
the energy production of the farm whilst
Financial analysis Acoustic measurements Market intelligence minimising its environmental impact. Users
of WindFarmer gain the competitive
Grid connection review Strategic and policy advice Strategic and policy advice advantage and accuracy of 30 years of
Training courses Training courses expert wind energy know-how.
Development Advanced, validated models for informed
decision-making
Environmental impact assessment
Robust, reliable software with local technical
Comprehensive wind monitoring service support
Wind farm layout design Multiple language versions
Energy yield and site conditions assessment
Grid connection support
Turbine selection
Pre-construction
Contract tendering and procurement
Civil and electrical design reviews
Management of grid connection
Formal energy yield assessment
Technical due diligence
WindHelm
Construction Portfolio management solution
Project management WindHelm puts users firmly in control of
their wind farm portfolio, regardless of its
Construction monitoring scale or the different turbine models used.
Owners’ Engineer Using SCADA data, WindHelm provides
Feasibility Development Preconstruction Construction Operation advanced analysis and reporting to facilitate
optimisation of assets.
Sophisticated SCADA control of any multiple
of mixed manufacturer turbines
Tracks availability, efficiency and resource
targets
Daily, weekly and monthly statistics plus
customised reports
Tailored project development services for the lifetime of your project 5
Feasibility Development Preconstruction Construction Operation

4. Global credentials
GL Garrad Hassan GL Garrad Hassan GL Garrad Hassan
Americas Asia & Pacific Europe, Middle East & Africa
Austin Bangalore Barcelona
Montreal Beijing Bristol
Ottawa Melbourne Cairo
Peterborough Navi Mumbai Cape Town
A unique global perspective
Portland Newcastle Copenhagen
Porto Alegre Seoul Cork
Querétaro Shanghai Glasgow
San Diego Tokyo Hamburg
based on experience
Santiago Wellington Heerenveen
Vancouver Hinnerup
Imola
Izmir
Kaiser-Wilhelm-Koog
Leiden
Lisbon
London
Madrid
Energy assessment
Oldenburg
analysing 20,000 MW of new projects per year Paris
25% of all projects worldwide Sint Maarten
70% of UK installed capacity Slough
75% of Irish installed capacity Warsaw
Zaragoza
60% of Indian installed capacity
52% of Italian installed capacity
50,000 MW in US
98% of Australian installed capacity
Operational assessment
15% of the world’s installed capacity
38% of Canadian installed capacity
Due diligence
over 25% of the world’s project financed wind farms
world’s largest wind farm portfolio acquisition
world’s first wind energy bond deal
Independent engineer
45% of US wind farms
the world’s five largest wind farm financings
42% of Italian installed capacity
65% of Spanish installed capacity
34% of Portuguese instaleld capacity
39% of Canadian installed capacity
67% of Latin American installed capacity
62% of Australian installed capacity
the first project financed offshore wind farm
Short-term forecasting
over 20% of the world’s operational wind capacity
Measurements
power curve measurements on 500+ turbines
load measurements on 100+ turbines
founding member of MEASNET
first ever load measurements on offshore wind farm
Products/ software solutions
world’s largest independent SCADA supplier operating 6,000 MW
industry standard wind turbine design and simulation software - Bladed
Bladed used to design world’s largest turbine
950+ staff, in 42 locations, across 24 countries
6 7

5. Global credentials Case Study: Multiple services across the lifecycle for projects in UK, Spain,
France and Italy
Client: Falck Renewables PLC, UK
A trusted partner providing GL Garrad Hassan has provided a wide range of services
to Falck Renewables PLC, a large independent developer,
tendering support, owner’s engineering services, due
diligence for project finance, asset management and
solutions internationally owner and operator of wind farms in Europe. Projects are
located in the UK, Spain, France and Italy.
optimisation, measurement services, inspection and
portfolio management software.
The services provided have been associated with all stages
of the project life cycle and include energy assessment,
Case Study: Technical due diligence and construction monitoring in multiple
countries including UK, Ireland, France and Germany
Client: Nord/LB - UK/Germany
Case Study: Provision of global energy development services to the
After structuring financing for UK wind farms in 2005, From issues associated with contractual coverage
world’s largest operator
Nord/LB further expanded its coverage in international of project risks, potential project delay events and
renewable energy project finance in 2006 with addressing construction related remedial works on site, Client: Iberdrola, Spain
investments in the Bindoo wind farm project in Ireland. through to input for a bankability advisory for a new
This was a significant step in establishing its relationship turbine entering the market , experts from GL Garrad Iberdrola is the world’s largest operator of wind power around the world, both onshore and offshore. Its experts
with Airtricity Renewables and in confirming its place Hassan have provided Nord/LB with reliable technical plants with a capacity of over 12,000 MW. GL Garrad have now worked in this technical advising capacity for
in the wind financing market. Since then, Nord/LB has advice – and, importantly, have proven that they are Hassan works closely with Iberdrola’s technical team to around 5000 MW of Iberdrola’s wind projects.
maintained its presence as a leading renewables lender able to react quickly and effectively in time pressured provide energy resource analysis for their wind farms
and debt advisor in Europe and North America, and GL transaction closings.
Garrad Hassan has provided technical due diligence and
The relationship that has developed with Nord/LB
construction monitoring to support it throughout the
demonstrates GL Garrad Hassan’s commitment to its
journey.
clients, as well as its ability to deliver the first-class quality
The effort and time in arranging finance for a small scale review product needed when making large investment
wind farm can be comparable to that of a large wind decisions. Its expert presence on the transaction teams
portfolio and GL Garrad Hassan’s due diligence activity contributes to a smooth review process, and supports the
for Nord/LB has been across the spectrum of investments. ongoing performance of the asset once the investment is
Case Study: Provision of services across the project lifecycle to a large North
made. American developer/owner/operator
Client: Horizon Wind Energy LLC, North America
Horizon develops, constructs, owns and operates wind assessment of energy production and provided expert
farms throughout North America. Based in Houston, opinion related to specific turbine technology risk;
Texas it currently has over 20 wind farms across the operation and maintenance planning and commercial
United States and has developed more than 3,400MW contracts.
and operates over 2,800MW of wind farms. GL Garrad
In addition, GL Garrad Hassan evaluated the foundation
Case Study: Provision of multiple services for development projects in Japan, Hassan has acted as a technical advisor to Horizon across
design and the electrical substation and collection
its portfolio, providing a range of services across the
South Korea, USA, UK, Italy, Spain, Norway project lifecycle, including: energy assessment, technical
system design to identify related risks. It also provided
construction monitoring services whilst verifying
Client: Eurus Energy Holdings Corporation, Japan due diligence, construction monitoring and end of
substantial completion of the wind farm in accordance
warranty inspection.
with the project documents and is responsible for
Eurus Energy is one of the pioneers of wind energy and now has 1,902MW of operational capacity globally Experts from GL Garrad Hassan have delivered a range verifying the condition of the turbine equipment in
development. Eurus stepped into the world of wind with projects in the USA, the UK, Italy, Spain, Japan, of specific studies and reports to Horizon. They have relation to expiring turbine supply, warranty, and
energy in 1987 in Mojave, California, USA. Since then, it South Korea and Norway. acted as technical advisors to support debt and equity operating and maintenance (O&M) contracts.
has been continually expanding its wind farm portfolio participation in the project, conducted independent
9

6. Research & Development
Dedicated to delivering the future
A selection of internal R&D projects
Wind energy is developing very rapidly. The start of the recent In parallel to these engineering developments has been
era can be dated back to the late 1970’s and hence is only the development of standards and certification. GL Garrad Lost production estimation during turbine downtime
really 30 years old. In that time, turbines have grown from Hassan has been a big contributor to this activity and remains Ongoing development of methodology to accurately calculate the production impact of significant downtime
diameters of 10 to 15m with power levels of 50 to 100 kW to committed to it as a central part of the development of the and investigate the applicability of nacelle anemometer wind speed for lost energy estimation.
the present size of 120-130m with power levels of 5,000 to industry as a whole.
7,000 kW - a growth of many orders of magnitude in just a .............................................................................................................................................................................................
A commitment to the science of wind energy is evident in
few decades. At the same time, wind farms have grown from Investigation of the use of remote sensing in complex terrain - LIDAR
every aspect of GL Garrad Hassan’s work. It is the driving
1 MW to 1000 MW! Such growth combined with a major
force behind many of the IEC committees and EU initiatives Ground-based remote sensing measurements in wind resource assessment has been gaining pace in the last few
improvement in reliability has only been achieved as a result
and was a founding member of the specialized wind turbine years. Other than price, which is likely to change, the main obstacle to its widespread use is the full
of a huge research and development effort. Meteorology,
measurement group known as Measnet. It is also recognised understanding of its behaviour in complex terrain. This ongoing project aims to address that topic.
aerodynamics, dynamics, control and civil, electrical and
for its pioneering work on all aspects of wind turbine and wind
mechanical engineering and material science have all played a .............................................................................................................................................................................................
farm modelling both onshore and offshore.
part.
In order to retain its position at the forefront of the industry, Health monitoring of wind turbines using SCADA data
GL Garrad Hassan has been at the forefront of this
GL Garrad Hassan champions R&D internally, as well as An assessment of the potential for using component temperature information typically available from a SCADA
development on the theoretical front and also via validation of
externally. In addition to its collaborative work with specialist system to conduct health monitoring of wind turbines.
new computational tools through its measurement activities.
institutions and consortia on externally funded R&D projects, it
The advent of Computational Fluid Dynamics (CFD) as a .............................................................................................................................................................................................
also has a dedicated internal R&D fund to allow its experts to
standard tool in wind farm evaluation and the introduction
apply for support to pursue advancement in areas related to Technology watch of grid codes
of LIDAR and SODAR remote sensing are good examples
their individual specialisms.
of the way that science has changed every day life in wind Active monitoring of the development of grid codes in Europe and participation in EWEA harmonisation working
farm development and analysis. GL Garrad Hassan has been group.
involved in every stage.
.............................................................................................................................................................................................
Icing research on operational projects
Production losses as a result of icing events can be quite significant in cold climates. Icing events can be
identified via site monitoring and weather forecasts and much can be learned to help predict losses during the
pre-construction energy assessment by directly comparing the performance of operational turbines during icing
events with the icing behaviour of pre-construction anemometry measurements.
.............................................................................................................................................................................................
Long-term wind speed trends in North Western Europe
Ongoing project since 2006 to record and analyse long-term wind speed trends.
.............................................................................................................................................................................................
Mesoscale modelling development
Mesoscale wind flow modelling can provide significant value in the early stages of project development. GL
Garrad Hassan undertakes continual development of knowledge and tools to support the commercial application
of mesoscale modelling with the aim of providing clients with accurate and practically applicable services.
.............................................................................................................................................................................................
WInd shear, uncertainities and thermal stability
Advanced methods are being developed to improve the vertical extrapolation of wind speed at real world wind
farm sites located in very different wind regimes.
10 11

7. Technical excellence
A selection of GL Garrad Hassan’s technical papers and presentations
• Validity check of numerical site calibration according to IEC 61400-12-1 ED.1 and MEASNET PPMP v4
Technical by nature • Influence of topographic maps on energy production assessments
• Enhanced ramp event forecasting using upstream wind measurements
• How to determine the portfolio effect based on wind regime dependency: European examples
• Wind tunnel measurements of the flow upstream a wind turbine: effects on the power production
• New developments in large wind farm modelling
GL Garrad Hassan is respected for its technical excellence The internal focus on technical rigour and quality has resulted
whether it be its depth of knowledge and service offering, in the development of many of the analytical methods that
its detailed measurements and data analysis, its analytical have now become industry standard tools. They are used both
modelling capability or market knowledge. The by-words of its by the experts within the company and by the industry as a
operation are technical rigour and independence. This stringent whole. Many of the tools which were originally developed to
approach is at the core of the business and influences all areas allow GL Garrad Hassan to provide an excellent consultancy
of activity. service have now become products for much wider use.
Since GL Garrad Hassan has no equity stake in any turbine or Given GL Garrad Hassan’s technical depth and its global
wind farm and does not patent its innovations it frequently breadth, it is able to provide solutions to any challenge in
publishes technical papers and its staff are regularly invited to the renewable energy field. GL Garrad Hassan only works in
speak at conferences and meetings around the world. It is a renewable energy and its management and staff are firmly WindFarmer
member of all the relevant associations and professional bodies committed to the fullest possible use of renewables globally –
and it serves on all the essential standards committees. harnessing the power of nature around the world. Both their Wind farm design software
approach and their impact are truly technical by nature!
Case Study: Setting European measurement standards - MEASNET GL Garrad Hassan’s wind farm design software, WindFarmer, This internal focus on detailed technical approach has resulted
originates from its pioneering wake modelling studies in the in the development of many of the analytical tools which are
A collaborative approach late 1980’s. Through spearheading R&D, WindFarmer has used by the experts within the organisation on a day to day
maintained its technological leadership in wind farm design basis. They were specfically designed to aid them in the process
ever since. Developed as an in-house tool, as early as 1993 of delivering technical excellence to GL Garrad Hassan’s clients.
For much of the last decade, the leading European To address this situation, the most experienced
WindFarmer featured an automatic layout optimiser, noise
wind test centres have been involved in developing European wind energy institutes worked collaboratively Most of GL Garrad Hassan’s industry standard software
modelling and a CFD representation of a wind turbine wake.
measurement standards to ensure that measurements as MEASNET in order to identify methods and rules to products were also initally developed to support its consultancy
In 1998 WindFarmer gained a first class interface, financial
performed are of high quality. ensure that high quality measurements carried out by business. There is probably no organisaton better placed
modelling and great visualisation tools. The first decade of
them were accurate and comparable. to understand the practicalities related to the development
Over the same period, several national and international the new millennium saw the release of a continuous stream of
and operation of wind farm projects which means that its
recommendations, standards and requirements for Today, MEASNET approved measurements are central to powerful new features: shadow flicker, electrical layout, design
technological solutions are grounded in years of physical
measurement procedures for wind speed and wind international wind turbine and wind farm development. turbulence, data cleaning, long term correlation, uncertainty,
consulting experience.
turbine systems have been developed or are still in The name MEASNET is associated with the high quality wake models for close spacing, offshore wind farms, very large
development. of measurements required by banks and investors to wind farms. There are many others in development to ensure
underpin their financing decisions. Results and energy that WindFarmer clients can continue to be assured of a
As a result, for certain measurements, there are several
predictions based on such measurements diminish the competitive edge.
different formal procedures related to the gathering
project risks and therefore considerably improve the
and evaluating of data and these can lead to different
financing conditions of the respective wind farm projects.
measurement results.
Wind turbine performance and loading measurement
Experience also showed that measurements performed
experts from GL Garrad Hassan’s WINDTEST services
by different institutes did not lead to comparable results,
were founder members of MEASNET and remain actively
even if they took the same recommendations into
engaged in the programme.
account.
12 13

8. Supporting the project developer
Case Study: Mesoscale Mapping
Client: Multiple - India
Project development solutions The process of identifying new potential wind farm
sites is time consuming and expensive.
even before it has been visited. Having analysed wind
projects all around the world, GL Garrad Hassan has an
unprecedented level of experience, bringing invaluable
GL Garrad Hassan supplies wind maps, based on
local knowledge to meso-scale work.
state-of-the-art meso-scale modelling techniques that
can significantly reduce this burden by providing a The map below was developed for the Indian market
Flexible support across all phases of the project preliminary prediction of the wind speed over a large and was given as a gift at the launch of one of GL
area. These predictions can be delivered before any Garrad Hassan’s Indian offices. Many other national
Wind farm developers have varying needs. GL Garrad Hassan recognises this fact and therefore
measurement equipment has been installed at a site or wind maps are also available.
offers flexible support. It operates a network of experts with specialist technical expertise. Any
combination of them will work together on a project dependent on a client’s requirements.
Together, their knowledge and skills can cover the entire project lifecycle, allowing clients to
mitigate the risks and avoid the delays and increased costs that developers commonly encounter
when trying to deliver their projects.
An experienced project development partner
Where clients require broader support across projects, GL Garrad Hassan offers engineers who are
specifically tasked with working across multiple internal specialist teams to deliver developers with a
seamless relationship from the feasibility stage right through to an operational project.
Case Study: Project development solution across five projects totalling 790MW
Client: Cartier Wind, Canada
GL Garrad Hassan began its relationship with Innergex programme, met mast installations and remote sensing
in 1999, prior to the inception of Cartier Wind, when equipment deployment and commissioning, data quality
the two companies involved in the partnership sought control and analysis, federal, provincial and local county
assistance in the different phases of project development permitting support, environmental assessments, specialist
of several of their projects. As part of its unique studies such as noise, visual, flicker, electromagnetic
systemic approach, it assisted, and is still assisting, this interference and land use issues, GIS mapping and
wind developer with several services including wind constraints analysis.
engineering and environmental permitting on 6 projects, High
In addition GL Garrad Hassan’s experts have provided
5 of which were awarded a PPA following a competitive
measurement services to assess pre- and post-construction
bidding process. GL Garrad Hassan acted during all
noise and electromagnetic fields at the site; they also
the phases of project development, construction and
provided wind farm layout optimisation, and conducted
operation to provide advice and developer’s tailored
an independent assessment of the energy production
consulting services.
at the wind farm, as well as carrying out performance
The services that GL Garrad Hassan has provided testing, including power curve measurements and
include: site prospecting and identification, design operational performance analysis, and acting as technical
and optimisation of the wind resource assessment expert to provide testimony at public hearings.
14 15

9. Case Study: Energy production assessment for the first wind farm in Sénégal -
Case Study: Onshore and offshore site prospecting study using GIS tools
the largest project in West Africa
Country: Canada
Client: Sarreole, France
In order to assist in identifying viable onshore and of complexity of terrain, conservation reserves, wildlife
offshore wind sites in the province, the client hired GL management areas, shipping lanes offshore, amongst Sarreole is developing the Taïba N’Diaye Wind Farm in extrapolation of the wind regime, as well as the impact
Garrad Hassan to undertake a detailed site prospecting others. The analysis also included the calculation of the region of Thiès in the west of Senegal and chose GL of significant high temperature shut-down for some
Garrad Hassan to carry out an independent analysis of turbine models.
study using GIS tools, including spatial analysis. The “land available for development” or “offshore area
the wind climate and energy production. 15 months of
approach to this study was to use a multicriteria analysis, available for development”, outside constrained areas, Based on the work, GL Garrad Hassan issued several
wind data had been recorded at the Taïba N’Diaye site
considering environmental, social, and technical factors, in order to identify project sites large enough to host a recommendations in order to reduce uncertainties.
from a meteorological mast up to a height of 50 m.
to identify viable large-scale sites. The analysis included large-scale project. One of the recommendations was to install a taller
The prediction of the variation in long-term wind speed meteorological mast on site in order to improve the
the consideration of the wind resource, the proximity
Finally, GL Garrad Hassan ranked the selected sites based over the site was challenging and experts from GL energy assessment. A new 100 m meteorological mast is
to the grid, and environmental factors such as the Garrad Hassan employed their specialist experience to now in position with further energy assessment planned
on the quality of the wind resource, the proximity to the
presence of protected areas, settlements, airports, radar assist Sarreole in resolving issues related to the limited for 2011.
grid and environmental risk.
installations, water bodies, inaccessible areas because source of consistent long-term wind speed data and the
uncertainty associated with the vertical and horizontal
Case Study: Project Development study and best practice road map for Case Study: Technical advisor for project financing of 56 wind farms in Italy
development in India Client: Multiple Lenders to Italian Vento Power Corporation (IVPC) projects
Client: Vestas Asia Pacific
A team of local and technical experts from GL Garrad execution of land purchase e.g. private land, government GL Garrad Hassan has been the technical consultant to Experts from GL Garrad Hassan have provided technical
Hassan assisted Vestas with its Indian development lease land, revenue land, as well as best practice for the Italian developer, IVPC, since it supported the project support for all 56 wind farms, working on behalf of
activities and delivered a detailed process road map electrical infrastructure, gaining all necessary approvals finance of its very first wind farm portfolio back in 1998. multiple lenders to the projects by providing a range of
that looks at the best practice approach. This road map and permits, and competitive differentiators. Since this initial project, IVPC has developed, constructed services including energy yield assessments, technical due
includes special consideration of the different local state and currently maintains wind farms across Southern Italy, diligence reviews for project financing and construction
The report outlined multiple best practices in relation to
regulations that provide Vestas with the knowledge Sicily and Sardinia with a total capacity of 1040 MW and operation monitoring.
electrical infrastructure that included power evacuation
to deliver world-class projects in Asia. The road map - approximately 20% of the current total Italian wind
schemes, grid availability and compliance, basic layout of
addresses land and infrastructure development and capacity.
the electrical infrastructure, supply, erection, testing and
assesses all the major activities required from conception
commissioning as well as required liaison and interaction
to development.
with local Government, Forest Department, Electrical
Utilising a unique systemic approach, GL Garrad Hassan’s Utility, Electrical Inspectorate of the State and State
experts provided the best route for a wind farm site Regulatory Commission.
development that looks at the different types and
17
16

10. Supporting the project developer Supporting the owner / operator
Operational project solutions
A suite of services to deliver operational success
In order to maximise the potential of a wind farm, it is essential that an owner / operator
monitors the project thoroughly on an ongoing basis and understands and acts upon the wealth
of information that is available to him. As the wind energy market matures, there is increasing
focus on maximising the energy capture and output from tubines, farms and portfolios in order to
support the future financial viability of the sector and its long-term investment appeal. GL Garrad
Hassan has been conducting detailed analysis of the resource and the technologies of operational
wind farms and portfolios for many years and offers a suite of services to deliver owners and
operators with optimal projects.
Advanced technical understanding of all operational matters
GL Garrad Hassan can facilitate both the collection of information pertinent to a project and an
owner/operator’s access to that data. Even more importantly, its experts are highly experienced in
translating information related to equipment, site and external events in order to allow an owner /
operator to take informed decisions and actions that will ensure that the project continues to be as
safe and effective as possible for the whole of its design life.
Case Study: Wind measurement campaign for multiple developers bidding to
build, own and operate Egypt’s first 250MW private wind power project
Client: Various
Case Study: Short-term forecasting worldwide
In 2008, the Egyptian Government championed first privately owned, 250MW Gulf of Suez Wind Power Client: Various
renewable energy by setting itself a target to meet 20% Project.
of the country’s electricity requirement from renewables
To support the individual bids, nine of the shortlisted
by 2020. Of this, 12% is expected to be delivered from GL Garrad Hassan delivers highly accurate and reliable In total, more than 30 clients in 14 countries rely on
developers have formed a steering committee to fund a
wind energy projects. Egypt currently has an installed wind power forecasting services around the clock forecasts to maximise the value of their wind farm
joint wind measurement campaign. GL Garrad Hassan
wind energy capacity of 550 MW which it aims to increase with operational availability in excess of 99.9%. It production. They are used by utilities to optimise their
was selected by the steering committee as the preferred
to 7,200 MW by 2020. To help deliver this goal, there is provides short-term forecasting for more than 33GW of wind power trading, ISOs to help integrate wind energy
consultant to specify, install, monitor and assess the joint
a commercialisation project underway that is focused operational wind projects worldwide including the whole reliably and efficiently, and by owners and operators to
wind measurement campaign. GL Garrad Hassan’s local
on engaging the private sector in phases. As part of the of the UK and Greece and, in the USA, California, the schedule their maintenance.
experts are scheduled to start work on site in November
first phase the Egyptian Electricity Transmission Company ERCOT region of Texas, the MISO region in the Midwest
2010 and the monitoring period is expected to run for a The forecasts adopt a combined physical and statistical
issued an invitation to tender and has shortlisted ten and the BPA region of the Pacific Northwest.
minimum period of twelve months with wind speed and approach - refining weather model inputs from a
potential developers to build, own and operate Egypt’s number of approved suppliers and enhancing the data
energy assessment work to follow.
to produce wind power predictions. This is done using
high resolution wind farm models, to take account of
site-specific conditions, and via statistical routines that
“learn” - adapting to the measured data.
A study published in 2006 revealed the potential benefit
of using GL Garrad Hassan’s forecasting service to be a
€10/MWh increase in the traded value of wind energy.
UK forecasted 24 hours ahead v actual power
18 19

11. Supporting the owner/ operator
Sample power curve measurement
2100,0
1900,0 0,50
power coefficient cp []
Case Study: Editorial for EWEA’s Wind Directions publication
electrical power [kW]
1700,0
1500,0 0,40
| science corner | 1300,0
1100,0 0,30
Optimising 900,0
700,0 0,20
wind farm operating efficiency 500,0
300,0 0,10
100,0
Keir Harman, Head of Asset Management and Optimisation
Services (AMOS), Garrad Hassan -100,0 0,00
0 2 4 6 8 10 12 14 16 18 20
It’s about efficiency, not just availability! Figure 1 illustrates turbine performance through wind speed [m/s]
Monitoring and optimising the operating efficiency time lapse animation. This method provides an
of conventional power generating plants has been overview of an operating wind farm over a whole
common practice for many decades but this has month with the power level, operating state and
not been the case with wind farms, where the turbine orientation shown schematically. A turbine
main focus to date has been on turbine availabil- operating in an abnormal manner can easily be
ity. A modern onshore turbine can be expected detected by comparison with its neighbours.
to be available for as much as 97% of the time Where a malfunction is suspected, tracking
[1] but the key question is ‘How efficient is the average power curves, based on the nacelle ane-
turbine during the time that it is operating?’ mometers, over several months confirms changes Figure 1 – Screenshot from
With Europe’s installed wind power capacity in relative operating efficiency and allows produc- a wind farm schematic time
now exceeding 65 GW [2], investment in availability tion loss estimation. The nature of a change in lapse animation
is ongoing, for example: the EU Reliawind project, shape of the power curve will indicate the type of
focused on improving wind turbine reliability, has malfunction.
€ 7.7 M of funding [3]. However, as the industry
becomes mature, profit margins are narrowing,
Modern turbines offer more flexible power con-
trol with variable speed and active pitch control-
Case Study: Power curve verification of multiple Spanish turbines
driving the need to monitor and optimise operat- led by complex algorithms. This allows a turbine
ing efficiency in order to maximise Return On to remain registered as 100% available while Client: Various
Investment (ROI). operating at reduced efficiency as a result of
either operator changes or automatically, in order
Avoid loss and enhance project value to manage structural loads. Resulting changes in Since 2007, it has been standard practice in Spain to GL Garrad Hassan’s experts have conducted many such
The economic benefit of optimising operating ef- operating efficiency are only effectively detected
ficiency can be illustrated by the following invest- using trend analyses.
verify the power curves of turbines used in large projects. power curve verifications in Spain. Where power curves
ment case: a 50 MW wind farm in Northern Europe More detailed forensic analyses may be For complex terrain, a measurement campaign starts with did not meet the contracted values, improvements were
with a capacity factor of 30%, and a capital cost of required in cases where the underperformance a site calibration as outlined in IEC 61400-12-1 “Power carried out which increased the power output of the
€ 72 M has a typical debt-equity leverage of 75%. is more subtle or intermittent. Figure 2 demon-
Mean annual revenue from energy sales will be strates a power and blade pitch curve for a turbine Figure 2 – Turbine power and
performance measurements of electricity producing wind farms significantly and led to successful power
around € 10 M. This means that, if 2% of revenue with an intermittent malfunction of the pitch blade pitch curves based on wind turbines”, and continues with the power curve curve verification for the contracting partners. Where
were clawed back through detailed monitoring and system. If this fault had remained undetected, 10 minute average SCADA measurement itself. Such measurements have to be manufacturers could not increase the performance, the
optimisation, a 7% (almost € 200 k) increase in revenue loss would have accumulated. data showing intermittent
annual equity distribution would be gained; in turn, Analyses that assess faults using parameters pitch malfunction
undertaken for hundreds of turbines. measurements resulted in the payout of Liquidated
this would increase the ROI from 13% to 14%. The such as blade pitch angle, rotor speed and yaw Damages to reimburse the owner for the missing
costs of the monitoring and subsequent repairs angle often highlight the cause of underperform- Once the initial results are produced, a decision can then revenue.
would be a fraction of this potential increase in ance. Aspects of the control system that com-
project value. monly cause degraded performance include yaw be taken on how to proceed. Naturally, the target for
system misalignment, pitch mechanism malfunc- every turbine supplier is to provide a power curve at In the future, for measurements in complex terrain or
How to monitor operating efficiency tion, sensor error (temperature, vibration) and least as good as the contracted one. The test may well for turbines with very large hub heights, new techniques
Monitoring the operating efficiency of a wind incorrect parameter settings. Once identified,
farm and fault-finding, using tools that utilise the faults can usually be rectified by a simple repair or prove that the measured power curve is at or above the will need to be adopted, such as 3D Sonic Anemometry
SCADA data and fault logs are essential on a re-calibration. contracted standard. If the contracted power curve is not or LIDAR. In order to retain a high quality approach to
modern utility-scale wind farm. Cross-checks with met, the measurement results can provide valuable input measurements, experts from GL Garrad Hassan have
maintenance and service reports, and ongoing dia- The future of monitoring and optimisation References
logue with the operations technicians, will enable In the future, techniques are likely to be auto- 1. Availability trends observed at for the improvement of the turbines and hence increase participated on an ongoing basis, for over 20 years, in
faults to be diagnosed and fixed. mated with low frequency condition monitoring operational wind farms: performance and revenue for the owner. the development and maintenance of both the IEC
systems programmed into the turbine controllers www.ewec2008proceedings.info
guidelines and the MEASNET procedures associated with
There are many techniques for identifying oper- and, ultimately, tasked with identifying problems 2. BTM Consult – www.btm.dk
ating performance issues: at the point that they occur in order to promote 3. EU Reliawind official website – the various different measurement approaches.
immediate remediation. www.reliawind.eu
WIND DIRECTIONS | July 2009 45
21