Concrete Wind Towers

With the anticipated growth in wind farms throughout New Zealand, increased emphasis will be placed on higher power outputs.  To meet this demand, wind towers will have to become taller and stronger in order to gain access to more powerful wind currents and accommodate larger turbines and rotor spans.  These requirements mean that concrete is the ideal construction material.

Depending on site conditions and accessibility, both in situ and precast methods of construction are suitable for concrete wind towers.  In situ construction can assist to overcome a problematic site, while also requiring minimal form and space.  Precast techniques enable high quality sections to be produced efficiently under controlled conditions.

Flexibility of construction methods means concrete is suitable for demanding offshore installations.  Gravity foundations can be constructed onshore and delivered for assembly using existing flat top barges.  A similar procedure can be followed for the delivery of individual precast concrete sections of the pylon.

Concrete’s high dampening properties can help reduce noise emissions and structural fatigue in wind towers.  The use of concrete in gravity foundations also improves dynamic response, while the wind towers in-service performance can be optimised further through pre-stressing.

Concrete wind towers may incur a greater initial investment than using alternative materials, but could prove extremely economical over their prolonged life due to durability and higher power generation potential.  Pre-stressed concrete wind towers can also accommodate multiple future-generation turbine retrofits, thereby increasing service life.

When constructing concrete wind towers, the levels of embodied energy and CO2 are significantly reduced in comparison with other materials, as is the period of operational time required to offset the energy consumed during their construction.

As a durable and versatile construction material, concrete can facilitate taller and stronger wind towers which can help New Zealand meet its current renewable energy supply targets and in so doing contribute to sustainable development.