July 18, 2014
Where and how the world finds its energy is changing. Yet how nickel-containing materials are enabling and supporting this dynamic process may not seem obvious until one looks closely.
By far the most important to date and with a long engineering and economic history is hydro power. It is there that the role of nickel-containing alloys in turbines, rotors, pumps and all the supporting engineering plant is understandably best known. The role of nickel and the role of hydro in providing enormous contributions of base load power is not going to change even as its percentage contribution to low-carbon renewable energy grids declines: there are only so many rivers, and hydro developments are not without their own environmental concerns.
Solar, wind and...
There are two classes of solar power technologies. The dominant and familiar technologies are the photovoltaic ones and while nickel has roles in the manufacture of panels and control equipment they are not essential to their functioning. Concentrated solar power (CSP) thermal technologies, however, are a different matter. The two main CSPs are parabolic troughs and power towers (see sidebar). They are industrial in scale and, depending on the technology, involve high temperatures, boilers and challenging fluids: molten salts or sea water. The enabling role of nickel is obvious because of its resistance to corrosion and high temperature strength. And while the photovoltaic technologies currently play the largest solar roles, the innovation and industrial potential of CSPs seems highest.
Wind turbines come in many shapes and sizes and while nickel-containing stainless steels are found in small turbines and in the fasteners that attach them to roofs or buildings, there are other nickel-containing alloys in the drive shafts, gear-boxes and generators in the familiar large wind turbines. The amount of nickel used in support of wind power generation increases when the turbines are mounted (or, in a few cases, floating) off-shore. Service platforms for the towers require the corrosion resistance of nickel-containing stainless steels or the anti-fouling properties of copper-nickel alloy 90-10 (UNS C70600).
Other challenging corrosion environments include the small but growing use and interest in tidal and wave power (with their salt water environments) and geothermal power where the hot water or steam (depending on the nature of the geothermal source) can be saline or sulphurous. Here again nickel-containing materials appropriate to the operating environments are needed and include stainless steels, high-nickel alloys, and copper-nickel alloys.
Future material needs
The energy picture is in flux and there are strong political, economic, and innovation forces at work that make it difficult to forecast the material needs of the energy industry as the technological mix changes.
Questions of materials supply and demand have led researchers to consider the implications of supply constraints to different economic and technical choices for energy production.1 Of current scenarios in use by different institutions, two were modeled for the period 2010-2050: Market First (where economics have primacy) and Policy First (where governments take strong measures to achieve social and environmental goals).
The mix of energy sources shows dramatic differences. Note, however, that it doesn’t matter which scenario or variation dominates by 2050. Nickel and nickel-containing materials and chemicals will be there to enable technologies and sustain the electrical grids upon which societies depend.