Using the right grout can mean a cheaper and more sustainable wind farm. Defiant of even the harshest, coldest and wettest weather, special grout materials can speed up the construction of the foundations of wind turbines. Luc Westhof, global key account manager for wind power at Construction Chemicals from BASF, explains why maintenance-free grouts are the savviest choice for wind farm owners.

Why is it so important to choose the right grout material for offshore wind farms?

Luc Westhof: Offshore wind farms are built to last for more than 25 years, which means the durability of all components of a wind turbine structure is of the utmost importance, including that of the foundations upon which the turbines are installed. One might say that durability is even more important for the foundations since there are no real repair methods if problems occur over the lifetime of the wind farm.
Depending on water depths and the size of turbines, different types of foundations are used to construct an offshore wind farm. The majority of the foundations use structural grout materials to connect the different components of the foundations. The grout forms the vital link between those foundation components, and transfers all the dynamic loads generated by the turbines and wave actions. MasterFlow offshore grout materials from BASF are highly sophisticated products and specific for each foundation type in order to meet the technical requirements of those offshore structures.

How can one best prepare the site for a foundation installation?

This question is better posed to specialist offshore contractors responsible for the foundation installation. However, the technically better and cost-optimised preparation is done well ahead of the offshore construction phase. This, of course, requires good seabed surveys and good planning for construction, including the necessary contingency plans that cover any eventuality that might occur.
For BASF, as the grout supplier, the preparation of the site starts with early discussions with our grouting contractor and the general contractor for the foundations. Careful planning of the deck layout can reduce the required area for grouting works. Selecting the optimum application method is a key part of good preparation for the foundation installation.

In what ways can the use of grout materials be optimised?

The choice of grout strongly influences the speed of the grouting works, the length of the weather windows needed to install the foundations, optimum use and turnaround of the installation vessels, and, thus, the overall cost of the foundation contract.
MasterFlow 9500, an ultra-high-strength grout, can be applied in very harsh conditions due to its rapid strength build-up and application temperature (down to 0°C). Installations in the shortest weather windows and in winter are possible, ensuring the shortest overall installation period for the wind farm. MasterFlow 9800 and MasterFlow 9600, the bulk-supplied grouts, reduce the footprint of the grouting equipment on the installation vessel to a minimum, and allow fast installation rates. As the latter materials are supplied in silo and are installed in a closed system without moving objects, grouting can be done in harsh weather.

How can costs be saved during the foundation installation by using Construction Chemicals’ MasterFlow grout materials from BASF?

MasterFlow 9500 facilitates the installation of the monopile foundations in the shortest period possible. Due to its rapid strength build-up, shorter weather windows can be chosen for the installation of those foundations. The robustness of the material and possibility to install the grout during cold periods ensure the duration of foundation contracts can be reduced.
The driver behind the cost-saving aspect of MasterFlow 9800 is its bulk supply. Warehousing in the harbour, open-top containers, crane operations during grouting and much more are eliminated with this grout from BASF. The very fast installation speed – well over 20m³ an hour – ensures that the grouting works no longer interfere with the critical path of the installation vessel. All MasterFlow grouts allow the fastest offshore installation, optimising the costs of the foundation contract.

How does the choice of grout impact the cost of energy and the subsequent revenue for wind farm owners?

Time is money, and this is even truer offshore. Being able to install the MasterFlow offshore grouts in rough weather and in winter allows the foundations contractor to complete the installation contract in time. The robustness of our offshore grouts is just another security to ensure that the foundations can be installed in the shortest period, hence lowering the cost involved with foundation installations.
Even simple things such as dust control with MasterFlow 9500 impact the overall vessel cost, as cleaning operations are eliminated. MasterFlow 9800 can be installed using only two-inch lines, and reduces the cost of the secondary steel of the foundations. The cost of a foundation contract for a project with jacket foundations can easily be reduced by about 10% when a bulk-supplied grout such as MasterFlow 9800 is used instead of a big bag-supplied grout.

What type of maintenance do your grout materials need?

Since we have only a one-off chance with the installation of the foundations and the grouting thereof, the MasterFlow offshore grouts are designed to be maintenance free. Whatever the requirements the designers of an offshore foundation have devised for the grout material, it needs to meet those specifications without exception. It is therefore highly important that the chosen grout material meets the needs of the wind farm-specific foundation.
A weak grout or material exceeding the requirements can create problems for the grout and the foundation in general. That is why BASF offers a range of unique offshore MasterFlow grouts to meet the specific requirements of the different foundation types.

What guiding principles shape the development of Master Builder Solutions’ products from BASF?

Providing a customised solution is always the prevailing principle in the development of BASF products. We develop solutions that not only address a single problem, but also greatly impact the entire value chain of an offshore wind farm. From the grouting contractor to the foundation installation company, from designer to investor, all requirements of all players are considered in the development of our offshore-specific grout materials. Since the cost of energy is of interest to everyone, including private households and large electricity-consuming factories, any grout development in Construction Chemicals from BASF is aimed at driving down the cost of the foundation installation, and the offshore wind farm as a whole.
In what ways can Construction Chemicals from BASF customise its grout offering to suit the needs of wind farm owners?
Besides the major impact our MasterFlow offshore grouts have on the overall installation cost of the offshore wind farm, our grouts guarantee excellent durability over the expected life time of a wind farm. Owners can take advantage of our innovative offering as investors are aware of the impact that our grouts offer on the financials of the offshore wind farm.
New offshore foundation types with updated material requirements are addressed by BASF throughout product development. Construction Chemicals from BASF has exclusive access to the BASF group’s cutting-edge technology. It is this innovative power within BASF that provides real customised solutions for end customers.
What type of sustainability practices does Construction Chemicals from BASF employ in the manufacture of its materials?
The Master Builders Solutions from BASF’s portfolio of class-leading construction products unites a common principle: increased resource efficiency to allow significant cost savings and a reduced ecological footprint. These benefits of advanced chemistry are proven by acknowledged measurement tools such as the BASF Eco-Efficiency-Analysis or the BASF Life Cycle Analyzer (LCA) tool.

What can we expect to see from Construction Chemicals from BASF in the future?

BASF will always be at the forefront of developing specific grouts that not only meet the technical requirements of specific offshore foundations. BASF will also ensure materials for the construction of an offshore wind farm are cost-optimised. Whether the materials affect the planning of a wind farm, the works during installation or the durability of the wind turbine installations, BASF will always aim to offer specially designed materials for the wind industry that strongly limit or overcome the typical problems of the offshore industry.
The ultimate goal of any new development from BASF is to offer a solution that allows for cost-effective offshore wind farm installation and operation over the expected lifetime of that wind farm.