Low Wind Speed Technology Phase I: Evaluation of Design and Construction Approaches 

for Economical Hybrid Steel/Concrete Wind Turbine Towers

BERGER/ABAM Engineers Inc.

Project Description: This work addressed the economic feasibility of concrete and 

hybrid concrete/steel wind turbine towers. The wind turbine/tower sizes that formed 

a basis for comparing concepts are:

• 1.5-MW turbine on a 100-m tower

• 3.6-MW turbine on a 100-m tower

• 5.0-MW turbine on a 100-m tower.

The design concepts included hybrid steel/concrete towers with 47–49-m concrete 

base tower sections and 51–53-m steel top tower sections and all-concrete towers 

100m tall. 

The study considered several construction approaches and developed prices for the 

concepts. A segmental precast concrete approach was developed in some detail for 

the 1.5-MW tower and was scaled for the 3.6- and 5.0-MW turbines. Additionally, 

researchers considered slip- and jump-forming construction methods to evaluate 

cast-in-place (CIP) concrete construction. 

A method for reducing the height of the heavy lifts for installing the turbine and rotors atop the tower was developed in some detail. The results indicate that the costs 

for the 1.5-MW/100-m tower—the hybrid steel/concrete, the CIP concrete, and the 

tubular steel towers—are all within 33% of each other. The CIP concrete approach 

modifies conventional industrial chimney construction and is estimated to be the 

lowest cost solution. The cost savings associated with nacelle semi self-erection 

at 50m versus 100m do not provide a strong cost advantage over the hybrid steel/

concrete. For the 3.6-MW/100-m tower, the CIP concrete concept is 68% of the 

estimated cost of the tubular steel concept. For the 5.0-MW/100-m tower, the CIP 

concrete concept is 63% of the estimated cost of the tubular steel tower concept.

Project Type: Conceptual Design Study 

Project Budget: $209,947

Industry Cost Share: $0

DOE Cost Share: $209,947

Planned Project Duration: June 2002–July 2004

Contacts:

NREL/Sandia: Berger/Abam:

David Simms, NREL Michael W. LaNier, BERGER/ABAM Engineers Inc.

1617 Cole Blvd. 33301 Ninth Ave. S, Suite 300

Golden, Colorado 80401 Federal Way, Washington 98003-2600

303-384-6942 206-431-2300

david_simms@nrel.gov lanier@abam.com

Schematic for a hybrid steel/concrete wind turbine tower.

A Strong Portfolio for a Strong America • Energy efficiency and clean, renewable energy will mean a stronger economy, a cleaner environment, and greater energy 

independence for America. Working with a wide array of state, community, industry, and university partners, the U.S. Department of Energy’s Office of Energy Efficiency 

and Renewable Energy invests in a diverse portfolio of energy technologies.

For more information contact EERE Information Center • 1-877-EERE-INF (1-877-337-3463) • www.eere.energy.gov

Produced for the U.S. Department of Energy by the National Renewable Energy Laboratory, a DOE national laboratory

Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 10% post consumer waste.

DOE/GO-102006-2202

March 2006

Current Status:

Project Complete—Final Report, LWST Phase I Project Conceptual Design Study: 

Evaluation of Design and Construction Approaches for Economical 

Hybrid Steel/Concrete Wind Turbine Towers 

www.nrel.gov/docs/fy05osti/36777.pdf