Uses of Concentrated Solar Energy in Materials Science

Abstract

In recent decades tremendous advances have been made in the development of new materials capable of working under increasingly extreme conditions. This advance is linked to the development of Materials Surface Engineering. The utilisation of techniques based on high density energy beams (laser, plasma, electron beam or arc lamps) in surface modification and metallic material treatment allow for the creation of non-equilibrium microstructures which can be used to manufacture materials with higher resistance to corrosion, high temperature oxidation and wear, among other properties. These techniques, despite their multiple possibilities, have one inconvenient property in common: their low overall energy efficiency. While it is true that the energy density obtained through a laser is three to four magnitudes greater than that which is obtained by solar energy concentration facilities, Flamant (Flamant et al. 1999) have carried out a comparison of the overall energy and the capital costs of laser, plasma and solar systems and came to the conclusion that solar concentrating systems appear to offer some unique opportunities for high temperature transformation and synthesis of materials from both the technical and economic points of view. It is important to bear in mind that the use of this energy could lower the cost of high temperature experiments. Combined with the wide array of superficial modifications that can be carried out at solar facilities, there are numerous other advantages to using this energy source. The growing (and increasingly necessary) trend towards the use of renewable clean energy sources, which do not contribute to the progressive deterioration of the environment, is one compelling argument. Solar furnaces are also excellent research tools for increasing scientific knowledge about the mechanisms involved in the processes generated at high temperatures under non-equilibrium conditions. If, in addition, the solar concentration is carried out using a Fresnel lens, several other positive factors come into play: facility costs are lowered, adjustments and modifications are easy to carry out, overall costs are kept low, and the structure is easy to build, which makes the use of this kind of lens highly attractive for research, given its possible industrial applications. These are the reasons that justify the scientific community’s growing interest in researching the possible uses of highly concentrated solar energy in the field of materials. But this interest is not new. At the end of the 18th century, Lavoisier (Garg, 1987) constructed a