Concrete Towers - a business case for sustained local investment

CONCRETE GROWTHconcrete materials engineers

Santie Gouws Specialist Consultant –Concrete Materials EngineeringDirector –Concrete Growth

Concrete Towers – a business case for sustained investment (I)

CONCRETE GROWTHconcrete materials engineers

Concrete Towers – a business case for sustained investment (II)

Relevance of Concrete Towers (I)

Global Development of Turbine Capacity

and Tower Height

IPCC – Intergovernmental panel on climate change 2011

CONCRETE GROWTHconcrete materials engineers

onshore

onshore

Offshore Offshore

Relevance of Concrete Towers (II)

US Wind Potential Capacity at 140m hub

height – published late 2014

CONCRETE GROWTHconcrete materials engineers

Relevance of Concrete Towers (III)

South Africa’s first wind farms 2013-2013

• Hub height 80 to 100m, turbine capacity 2 to 3 MW

• Concrete towers cost effective from 90m

• Concrete towers – ‘local’ by their very natureCONCRETE GROWTHconcrete materials engineers

onshore

onshore

Offshore Offshore

Relevance of Concrete Towers (IV)

• Acciona Windpower’s Gouda towers

• Local Investment

• Benefits achieved

CONCRETE GROWTHconcrete materials engineers

Acciona Windpower’s Concrete Towers (I)

• Patented precast concrete tower design,

complete with engineering drawings and

manufacturing specifications

• 100m and 120m hub heights available

• Developed in-house and commercialized over

the past 8 years

• Reproduced internationally through use of local

contractors without the need for specialized

labour or equipment

• Rolled out in Spain, Brazil, Mexico, Poland

• Now also in

South Africa

• 250 towers to

date

CONCRETE GROWTHconcrete materials engineers

Acciona Windpower’s Concrete Towers (II)

Gouda Wind Farm – South Africa

• 46 towers with 100m hub height

• 5 cylindrical 20m concrete sections per tower

• 2 - 4 precast concrete segments per 20m section

• 17 precast concrete segments per tower

• 782 segments in total from 5 moulds ~ 16 500 m3

• ~ 60t per segment

• Manufactured in CT

• Transported 100 km

to Gouda site

• On site assembly

CONCRETE GROWTHconcrete materials engineers

Acciona Windpower’s Concrete Towers (III)

Precast Concrete Manufacturing Process

Acciona Windpower’s Concrete Towers (IV)

On-site Assembly Process

Investment into Localization (I)

Key Local Role Players for Gouda

• Concrete Units (SA) with engineering input from

Windtechnic (Spain) – precast manufacture

• Argent - Megamix - concrete

• RSC and Steeledale - reinforcement

• Afrisam - aggregates

• PPC Cement – cement

• BASF SA - admixture

• Absolute Rigging - transport

• B D Materials – grouting contractor

• Sika SA – grout/epoxy sealant/chord

• Concrete Growth – quality management of

precast manufactureCONCRETE GROWTHconcrete materials engineers

CONCRETE GROWTHconcrete materials engineers

Investment into Localization (II)

Precast capability base prior to the project

• Peak production and logistics

management rate ~ 500m3/week

• Under-roof factory ~ 3000m2

• Open-air factory area ~ 10 000m2

• Handling equipment

• 100t gantry crane

• 10t reinforcing gantry

• Production staff ~ 50/month

• Steel reinforcing tensile

strength of 450MPa

• Concrete design strength of

50MPa

• Normal vibrated concrete

CONCRETE GROWTHconcrete materials engineers

Investment into Localization (III)

Manufacturing requirements for Gouda

• 10 month manufacturing period ~ peak 650m3/w

• Structural concrete to European Standards

• Steel Reinforcing Tensile Strength 500MPa

• Concrete Design Strength of 75MPa

• Self-compacting concrete, no vibration

• Moulds by AWP,

set up by

contractor

• Dimensional

tolerances

to < 1cm

CONCRETE GROWTHconcrete materials engineers

Investment into Localization (IV)

Factory upgrade by Concrete Units

• Additional under roof area ~ 1100m2

• Handling equipment increased

• Two additional 35t gantry cranes

• Additional 16t reinforcing crane

• Time Frame ~ 10 weeks (during project start-up)

• Financial Investment ~

R12 000 000

CONCRETE GROWTHconcrete materials engineers

Investment into Localization (V)

Investment into people and technology

• Technology transfer through Acciona

Windpower’s ‘Manufacturing Instructions’

• ‘how to’ manual based on Spanish

conditions, materials, methods

• Learning by doing and ‘localizing’

• High strength self-

compacting concrete

• Vertical Joints

• Measuring of performance

by Acciona’s Quality

Management System

Measuring the performance

• Acciona Windpower’s Quality Management

System

Investment into Localization (VI)

CONCRETE GROWTHconcrete materials engineers

Benefits realized (I)

CONCRETE GROWTHconcrete materials engineers

Investment into people

• Quality Management System as measurement

tool

Local expenditure on raw materials

782 segments ~ 97 % local content

Manufacture of Segments

Concrete (material) 16 500 m3 R 30 000 000

Reinforcement 2 800 t R 26 000 000

Post tensioningcable

100 t R 2 000 000

TPA – lifting hooks 6256 nr off R 2 000 000

Metallic ducts 8 300 m R 300 000

Assembly of Segments

Grout 38 t per tower

Benefits realized (II)Jobs created and new skills learnt

(Peak production staff component)

• Engineering component (manufacture)

• 10 persons (4 Spanish)

• Quality management team

• 6 persons

• Total staff component ~ 216 persons

• 48 persons sourced from Gouda

• 25 % of these 48 will be incorporated into

the next project

Learnt to work with high strength self-

compacting concrete

Learnt to work in highly industrialized

precast set-up with strict Quality Control

782 Segments Completed – on time and within budget

Cost and lead-time reductions possible for future wind turbine

tower supply.

Benefits realized (III)

0

100

200

300

400

500

600

700

800

900

0

1

2

3

4

5

6

05-Feb19-Feb05-Mar19-Mar02-Apr 16-Apr 30-Apr14-May28-May11-Jun 25-Jun 09-Jul 23-Jul 06-Aug20-Aug03-Sep17-Sep 01-Oct 15-Oct 29-Oct12-Nov26-Nov10-Dec24-Dec

277 units in 5 months55 units/month

470 units in 3,75 months125 units/month

Peak production rate 650 m3/week

Localization of Acciona Windpower’s

Precast Concrete Tower Technology

INPUT

• Low capital investment and short implementation

phase of factory upgrade

• Training through learning by doing and measuring

OUTPUT

Gouda Wind Farm 46 WTG’s, 3MW on concrete towers

97% local content in tower segments

216 jobs created, some permanent

High skills and technology development in local

precast concrete manufacture industry

Potential for future reduction in cost and lead time

Potential for application of new skills back into local

construction industry

Real risk of loosing skills if investment not sustained

Conclusions