eolic truss tower_offshore_may2011 (1)

Contents:

CONCEPTPRODUCTION AND TRANSPORTCONSTRUCTION ONSHOREOFFSHORETECHNICAL AND ECONOMIC ADVANTAGESPATENTS / AWARDSINVENTORS / CONTACTS

CONCEPT

There is a need for taller towers for wind power than those currently available, especially for offshore use.

Our typical solution for onshore have about 125m height.

The tower for offshore allows their use in waters until 50m deep, with 75m above the sea level.

The proposed structural solution uses precast concrete elements -columns, cross beams, and diagonals – in order to build a space truss, optionally prestressed. This kind of solution is not limited by transport gauges.

The towers are structurally optimized, both in terms of resistance and control of natural vibration frequency.

This solution has indisputable advantages over steel towers and solutions in precast concrete shell.

CONCEPT

This tower has the advantage of allowing fast construction using precast concrete elements, which are easily transportable and in reduced number.

This solution saves costs in the foundations, in production, transportation and assembly of the tower elements, as well as in their maintenance.

CONCEPT

Moreover, according to the characteristics of the selected concrete, the size of the elements, the spacing between them and the degree of prestressing, it is possible to control the natural frequency of vibration of the tower (onshore or offshore), in accordance with the equipment requirements.

CONCEPT

PRODUCTION

TRANSPORTATIONThe towers have reduced costs of production, transportation, installation and maintenance.

The element’s transportation is not conditioned by current dimension limits. So, the transportation limits do not influence the geometry of the tower.

The tower elements are prefabricated in concrete, a durable material, with strict quality control.

CONSTRUCTION

High speed assemblage: thanks to the use of long elements and fast structural connections.

Foundations:The significant weight of the tower has a stabilizing effect and allows an important reduction of the required foundation weight, either onshore and offshore, leading to cost reductions;

ONSHORE

OFFSHORE

TECHNICAL AND ECONOMIC ADVANTAGES

COSTS• Cost reduction of about 15-20% while compared with other

onshore solutions.

CONSTRUCTION (INOVATIVE DESIGN)• This system is not conditioned by current dimension limits in

the transportation, so it is possible to optimize the geometry of the tower with less restrictions;

• The structural optimization of the tower, both in terms of resistance and control of natural vibration frequency, has more variables and less restrictions than the existing solutions;

• The proposed solution enables the construction of high towers to support large turbines onshore and offshore.


CONSTRUCTION

• A significant improvement of the structural damping and dynamic behavior, allowing for the reduction of fatigue effects;

• Excellent response to seismic actions, thanks to the high ductility of the elements of the tower and its structural damping which increases in situations of extreme loads. This behavior enables the structure to dissipate energy in the event of an earthquake, contrasting with the behaviour of steel towers.

CONSTRUCTION

• The connections between elements are reliable, maintenance free, easy and fast to implement on site;

• Simple, cheap and reliable connections of the columns to the foundation.

FOUNDATIONS

• The significant weight of the tower has a stabilizing effect and allows an important reduction of the required foundation weight, leading to a reduction of costs;


FUNCTIONALITY

• The space inside the tower allows mounting of equipment in a single level, without constraints of space;

• Easy mounting of equipment to the elements of the tower.

MAINTENANCE• Reduced need for maintenance, in contrast to the steel

towers;• Tolerance to impact damage or accidental actions, as it is

easy and economical to repair in such circumstances.

TECHNICAL-ECONOMIC ADVANTAGES

DURABILITY

• Higher durability of concrete structures compared to steel towers - especially in maritime environments - due to the protective action of an appropriate reinforcement concrete cover. This durability increases with the use of high-performance concrete;

• The durability of concrete towers is much higher than that of the turbine. This opens the possibility of future replacing of wind turbines by larger power ones, expanding the amortization period of the initial investment, which is especially high in offshore facilities;


ENVIRONMENT

• Less noise due to the damping effect of the concrete;

• Reduction of CO2 emissions in the manufacture of the tower (around 55 to 65% of the emissions involved in the manufacture of a metal tower);

• The material of the towers is totally recyclable.


PATENTS

Patent pending:• Portuguese Institute of Industrial Property – April 2009• WIPO - PCT – April 2010

AWARDS

Winners of the 5th edition of the “Concurso Nacional de Inovação BES 2009 ” (BES National Awards for Innovation)in the sector of New Materials and Industrial Technologies

INVENTORS / CONTACTS

Carlos Chastre Rodrigues & Válter Lúcio

PhD in Civil Engineering,Structural engineers, specialists on precast concrete structures

Professors at Universidade Nova de Lisboa

[email protected] | [email protected]. Prof. Veiga Ferreira 21C (Jardim)1600-802 Lisboa – Portugalphones: +351.917563647 and +351.917624993