GEF/UNDP/DOE CBRED PROJECT
“Philippines: Capacity Building to Remove Barriers to Renewable Energy Development”
MANUAL FOR ENGINEERING SERVICE
PROVIDERS IN WIND ENERGY
DEVELOPMENT
Prepared by:
International Resources Group – Philippines, Inc.
Unit 2303 Medical Plaza Ortigas Condo.
25 San Miguel Ave., Ortigas Center
Pasig City 1600
Revised First Interim Report
Training Modules for Wind Energy Development
Manual for Engineering Service Providers in Wind Energy Development
Introduction
This manual is presented as a guide to local Philippine wind consultants in providing the various services
required by wind farm developers in various stages of project development. It is a comprehensive approach
and is meant solely to give a general idea of the activities relevant to each stage and the resources that may
help in further defining such activities thereafter.
General Wind Energy Information
Various literature and websites provide information on wind energy as a science and industry. For
introduction to wind energy, one of the best resources online is found in the official website of the Danish
Wind Industry Association, www.windpower.org. It provides an easy-to-follow discussion on the topics of
wind resource, history of wind energy, wind turbine generators (electro-mechanical) and wind farms, among
others.
An updated version of Wind Energy – The Facts can also be downloaded from the official website of the
European Wind Energy Association (EWEA), www.ewea.com. Aside from discussions on the development of
the wind industry, it also provides a discussion on the various support mechanisms that enabled the success
of the wind industry in different countries.
Publications such as Wind Energy Handbook by Burton et. al. (Wiley Publications) and Wind Energy Comes
of Age by Paul Gipe (Wiley Publications) also provide excellent discussions on wind energy but in most parts
tend to be very technical.
Pre-Feasibility Study
The pre-feasibility study generally covers the identification of a potential wind farm site and an initial
assessment whether a short-term (12 months minimum) in situ measurement should be carried out, i.e. wind
measurement campaign, to further validate the wind resource.
Several criteria are observed in qualifying a site for further investigation. Among these are:
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physical evidence of strong wind, e.g. tree flagging
previous / existing wind measurements within or near the site
access to site
land classification / availability
proximity to grid connection
orography (i.e. simple or complex terrain) / elevation
vegetation or forest cover
power demand
protected areas
In the Philippines, it is also advisable to check the zone in which the site is located as defined in the National
Structural Code of the Philippines (NSCP). Zone 1 areas are those that are normally along the typhoon paths
and require very high survival wind speeds, exceeding those of IEC Class 1 wind turbines. Those in Zone 2
typically require turbines with at least IEC Class 2, but it is possible that Class 1 or S (site specific) would be
CBRED Project: RE Engineering Service Industry Development (ESID Subcontract)
Subcontractor: International Resources Group – Philippines, Inc.
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Training Modules for Wind Energy Development
required. Class 3 are rarely hit by typhoon but they almost always have low wind resources as well.
(International Electrotechnical Commission www.iec.ch)
It is also recommended to contact the local government units (LGU) that have jurisdiction over the proposed
site during this stage. The LGU’s can normally provide development plans and zoning within their
jurisdiction, a factor that would greatly affect the extent of any future wind farm development. Once the initial
project boundaries are defined, it would be advisable to make initial contact with the relevant landowners as
well.
A location for the installation of a meteorological mast must be established during this phase. The area has
to be representative of the general terrain of the development site, but at the same time must have sufficient
area for laying out and assembling the mast during erection. This flat area would depend on the height of the
mast and the specifications of the fabricator. Two fabricators of complete systems are NRG
(www.nrgsystems.com) and Second Wind (www.secondwind.com), both based in the United States.
Once the mast is installed and operational, the feasibility study stage begins.
Feasibility Study
The feasibility study is done to ascertain the viability of developing a wind farm within a pre-selected area.
One major activity in this stage is the wind measurement campaign where a meteorological mast is installed
at the site to measure for at least one year. Wind speeds and direction (10-minute averages) are recorded
and stored in a data logger for extraction on a regular basis, e.g. monthly. Though several systems are now
equipped with GPRS downloading capability, it is still recommended that a monthly visit to the site is carried
out for inspection of the mast to maintain a high degree of data reliability.
Data to be used for wind resource analysis must be full-year data so as not to introduce seasonal bias in the
analysis. A data recovery rate of at least 90%, random missing data, should also be observed.
Several softwares can be used to process the wind data in conjunction with terrain description to produce a
regional wind climate. The most basic software is WAsP (Wind Atlas Analysis and Application Program) by
Risoe National Laboratory of Denmark (www.wasp.dk). Other available softwares are WindPro by EMD
(www.emd.dk) and WindFarmer by Garrad Hassan and Partners (www.garradhassan.uk). These softwares
can also be used for micro-siting (defining the location of the wind turbines in a wind farm) and estimating the
annual energy production (AEP).
The AEP determines the revenue level of the proposed project and is used accordingly in the financial and
economic analysis of the project. The profitability criteria used are typically the financial internal rate of return
(FIRR), economic internal rate of return (EIRR), return on equity (ROE) and net present value (NPV).
Other activities that should be carried out during this phase are:
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System Impact Study
Geotechnical Studies
Contour Mapping
Environmental Impact Assessment
Information Campaigns
System Impact Studies are carried out on contract by the National Transmission Corporation (Transco),
www.transco.ph.
CBRED Project: RE Engineering Service Industry Development (ESID Subcontract)
Subcontractor: International Resources Group – Philippines, Inc.
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Training Modules for Wind Energy Development
Design & Construction
Once the viability is confirmed and a suitable financing is secured, the project can proceed to the design
phase. A typical way of developing the project is through an EPC (Engineering, Procurement & Construction)
contract, also known as a turnkey contract. Several firms, sometimes the wind turbine fabricators
themselves, can provide this service which is recommended when the owner has insufficient experience in
building a wind farm.
Leading wind turbine / wind farm suppliers are Vestas (Denmark), Enercon (Germany), GE Wind (USA),
Gamesa (Spain), Bonus-Siemens (Denmark), Nordex (Germany) and Suzlon (India).
Wind turbine generators should be designed to withstand the conditions at the project site including, but not
limited to, survival/extreme wind speed, lightning strokes, seismic factor, wind regime, grid restrictions
(Philippine Grid Code) and corrosion. Some of the applicable codes for the design of a wind farm are the
following:
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American Concrete Institute – ACI
American Gear Manufacturers’ Association – AGMA
American Institute of Steel Construction – AISC
American National Standards Institute – ANSI
American Society of Civil Engineers – ASCE
American Society for Testing & Materials – ASTM
American Welding Society – AWS
Association of Structural Engineers of the Philippines – ASEP
British Standards – BS
Det Norske Veritas – DNV
Germanischer Lloyd – GL
National Electric Code – NEC
Philippine Electrical Code – PEC
National Electrical Safety Code – NESC
National Electrical Manufacturers Association – NEMA
International Electrotechnical Commission – IEC
Institute of Electrical and Electronics Engineers – IEEE
International Organization for Standardization – ISO
Underwriters Laboratory – UL
In particular, IEC 61400-1 defines the safety parameters considered in designing a large wind turbine. This in
turn is used by certifying bodies such as Risoe National Laboratory, Det Norske Veritas (DNV) and
Germanischer Lloyd (GL) to certify a particular wind turbine design.
Commissioning & Testing
Once the wind farm is built, functional tests of the individual components are carried out prior to acceptance.
Depending on the component (i.e. electrical, mechanical, structural, etc.), the applicable standards are used
for drafting test protocols.
One particular test that should be carefully carried out is the power curve test. This is due to the fact that a
wind turbine’s power curve is a guarantee item and as such has to be verified by the owner. The accepted
CBRED Project: RE Engineering Service Industry Development (ESID Subcontract)
Subcontractor: International Resources Group – Philippines, Inc.
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procedures for testing the power curve are contained in IEC 61400-12. Normally, a third party with an
expertise in WTG power curve testing is engaged for this purpose to avoid any bias. Some of the companies
that provide such service are Risoe National Laboratory (Denmark), Tripod (Denmark) and DEWI (Germany).
Operation & Maintenance
A modern wind farm can practically operate unmanned or with minimal human interference. It is however
recommended, especially for investors venturing into wind farms for the first time, to hire an operations &
maintenance service provider to run and maintain the plant for at least the first two years. It is usual practice
to hire the WTG fabricator for this task, particularly during the defects liability period (2-5 years).
CBRED Project: RE Engineering Service Industry Development (ESID Subcontract)
Subcontractor: International Resources Group – Philippines, Inc.
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MANUAL FOR POTENTIAL WIND TURBINE
GENERATOR TOWER FABRICATORS
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Subcontractor: International Resources Group – Philippines, Inc.
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Training Modules for Wind Energy Development
Manual for Potential WTG Tower Fabricators
Introduction
In the absence of any local WTG tower fabricator in the Philippines, this manual is presented as an overview
of the typical production process for steel towers. The aim of this document is to give a general description of
the requirements for producing this WTG component.
It would be expected that any local WTG tower fabricator would cater to the requirements of a particular WTG
manufacturer that has secured a supply contract for a wind farm project in the Philippines. In such case, the
design and specifications for the tower would come from such WTG manufacturer and fabricated according to
specs by the local tower fabricator.
The tower design is part of the safety requirements in IEC 61400-1 since the WTG is classified as a whole.
Raw Materials
The basic raw materials for tower fabrication are the steel sheets. Thickness (gauge) is specific to the WTG
model and manufacturer. The tower fabricator shall observe strict quality control standards when receiving
the raw materials for production.
Other components are the steel flanges that connect major tower sections together and to the foundation, the
tower door/door frame, and minor items such as ladders, cable raceways, and landing platforms.
Cutting
The steel sheets are usually cut to banana peel shapes using microprocessor-controlled plasma cutters. This
peculiar shape is necessary to achieve the tapering profile of the tower section once the sheet is rolled.
The provisions for the tower door are also cut from the lower tower section at this stage.
Rolling
Heavy steel rollers are used to form conical subsections from the cut metal sheets. The arc is carefully
measured using steel templates several times during the rolling process. The tricky part in this process is to
keep the tension (pressure) of the steel rollers different at the two sides in order to make the plate bend
properly.
Welding
Each subsection is welded with a seam lengthwise, typically with a powder welding machine. To connect the
subsections together, they are placed on a rolling bed that slowly rotates while two welders simultaneously
weld from the inside and the outside.
Flanges are likewise welded at the ends of the completed tower sections for connection to the foundation
(lower section) and the next section (middle section).
CBRED Project: RE Engineering Service Industry Development (ESID Subcontract)
Subcontractor: International Resources Group – Philippines, Inc.
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Revised First Interim Report
Training Modules for Wind Energy Development
The welding seams are checked either with ultrasonic or x-ray device, with the more important seams
checked 100% while less important ones on a sample basis.
Surface Preparation and Painting
Surface preparation and painting are carried out in accordance with applicable ISO standards to achieve the
level of protection specified by the customer. In coastal areas, special coating against salt corrosion is used
to ensure the 20-year life of the tower.
Balance of Works
Once painted, internal auxiliaries such as ladders, cable raceways, etc. are installed. In most cases, the topmost part of the tower is shipped with the cables rolled up inside. After assembling the tower and the nacelle,
the cables are untied and allowed to unroll downwards.
Shipment to Site
Tower sections can be as long as 30 meters and are very heavy. Shipment to site is best left to a logistics /
trucking contractor who is familiar with the load limits of roads and bridges, traffic regulations, best route,
possible shipping schedules, and loading/ unloading facilities.
CBRED Project: RE Engineering Service Industry Development (ESID Subcontract)
Subcontractor: International Resources Group – Philippines, Inc.
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