Welcome to the Glass Age

72 sunlight yet be stable against ultraviolet wavelengths. Thin borosilicate glass tubes are shown to meet these requirements particularly well. Although such glass-based bioreactor systems require higher investment compared to those made from polymers like polyethylene or polyvinylchloride, their superior performance, low maintenance cost, and long life (>50 years) also make them economical over time. Glass for energy storage technologies Often there is a mismatch in the timing of energy production and its consumption in the required form. To resolve this mismatch, the energy must be converted into a form that can be stored for a period and then converted back into a form that can be utilized. The process of energy conversion should be sufficiently fast with minimal loss. Typically, electrical or thermal energy needs to be stored. The former is stored by converting it into a mechanical, chemical or electrochemical form, while the latter is stored through a change in material temperature, such as latent heat of phase change, or as thermochemical heat of change of a material’s chemical structure. At present glass is not central to these applications in use today on large scale but is emerging as one of the most promising materials for future advancements. Examples for storing electrical energy include solid state batteries relying on electrochemical conversion and generating hydrogen relying on chemical conversion. In emerging batteries, glass is useful both as an ion conducting solid electrolyte and an electronic-ionic mixed conductor for electrodes. Hollow glass microspheres are proving to be a safe host for storing hydrogen that is produced by electrolysis of water. For storing thermal energy, the most widely used approach exploits phase change materials with large latent heat and then sensible heating of the melt of high specific heat. Here typical glass forming oxide melts are attractive over other salts due to their high characteristic energies and inertness towards metal containers. Summary The optical transparency to sunlight, high resistance to attack by chemicals and damage by radiation, versatility to dissolve high concentrations of extraneous oxides, and capacity for economic fabrication in complex shapes make glass indispensable to the realization of various energy technologies. Already, it is widely used in harvesting solar and wind energies via photovoltaics, solar-thermal, photosynthesis and windmill technologies. It is the material of choice for environmentally safe disposal of high-level nuclear waste that results from nuclear energy production. Further improvement in the performance of glass in these existing applications is expected with further optimization of compositions. Recent advancements in R&D have demonstrated proof-of- concept for applications of glass also in energy storage technologies such as solid-state batteries, hydrogen as a green fuel, etc., thus indicating tremendous opportunities alongside the challenges for growth of glass to address the problems of the energy sector.