2. 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.
3. 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
4. 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
5. 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
6. PRODUCTION
TRANSPORTATION
The 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.
7. 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;
10. 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.
11. TECHNICAL AND ECONOMIC ADVANTAGES
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.
12. 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;
TECHNICAL AND ECONOMIC ADVANTAGES
13. 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
14. 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;
TECHNICAL-ECONOMIC ADVANTAGES
15. 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.
TECHNICAL-ECONOMIC ADVANTAGES
17. 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
18. INVENTORS / CONTACTS
Carlos Chastre Rodrigues & Válter Lúcio
PhD in Civil Engineering,
Structural engineers, specialists on precast concrete structures
Professors at Universidade Nova de Lisboa
chastre.fct@gmail.com | vjglucio@gmail.com
R. Prof. Veiga Ferreira 21C (Jardim)
1600-802 Lisboa – Portugal
phones: +351.917563647 and +351.917624993
