Renewable energy industry reports suggest that more than 60% of all future power capacity will come from renewable technologies, only 25% will be in the form of gas or oil, with the remainder being nuclear. Furthermore, experts estimate in the next 10 to 15 years, the market share of renewables will increase by more than 35% worldwide.
To meet these lofty expectations, turbine manufacturers and sub-component suppliers are being tasked with designing and building state-of-the-art technologies that are efficient, yet cost effective. To be competitive under the high-price pressures of the wind industry, even the most elementary of components will be under close scrutiny. This tight oversight will allow opportunities for new technologies to be developed using alternative materials in order to make the wind turbine more efficient and economical, while also being environmentally friendly.
Efficiency vs. cost
The balance between high-quality, efficient products and cost effectiveness requires R&D departments of companies in the wind industry supply chain to think outside the box. One area in particular, is the conductor material itself, which is often the cable’s largest expense. Cable and wire manufacturers have traditionally used copper as the conductor material of choice for cables in wind turbines. However, copper prices are extremely volatile due to its varying degree of demand. Therefore, cable R&D engineers are looking at alternative conductor materials or copper alloys that perform comparably to pure copper, but have far less price volatility.
One such material is aluminum, which has been used as a conductor material in wind turbines, but has always been stiff and not easy to use. Some manufacturers, however, have developed a cable with flexible-aluminum conductors that are safer, up to 60% lighter, and easier to install or replace.
Flexible-aluminum cables are diesel locomotive (DLO)-like cables, best used in the tower area of the turbine (second photo, right), with performance characteristics comparable to standard copper cable, but at a fraction of the cost.
The cost savings go beyond just switching the conductor material from copper to aluminum. Installation and maintenance costs are significantly reduced since the complete power cabling system, from generator to inverter, is only interrupted in the loop. This maximizes cable safety and reliability compared to the conventional installation method, which interrupts the cable at every tower section. Furthermore, installation time is reduced from days to hours.
Additionally, cable connection technology is also seeing a shift to alternative or hybrid metals, such as lugs being made completely of aluminum or aluminum-copper hybrids.