Glass materials are an essential component in solar energy applications which comprise, e.g., photovoltaics, solar thermal collectors, greenhouses, and algae reactors, by acting as a protective and light transmitting barrier [1, 2]. Adding functionalities and optimizing the glass and coatings in an intelligent way creates opportunities to enhance the properties of the cover glass material for its use. 

Glass as a cover material for solar energy applications constitutes a significant part of the costs and a major part of the weight. However, glass is an important component for efficient light capture and protection to the environment. The R&D of cover glass for solar energy applications have so far received limited attention even though it is an important material for our future sustainable development and will likely require an increase of the flat glass production in the future. Recent research efforts have provided knowledge of which properties that needs to be optimized - balancing efficiency, service lifetime and cost. The challenges of cover glass for different solar energy applications differs somewhat but all have in common the efficient solar light capture and protection to the environment. Thus, the know-how can be used in several different industrial sectors. The fundamentals of cover glasses for solar energy applications as well as previous and on-going project concepts will be presented. This includes i) state-of-the-art of cover materials for greenhouses [2], ii) results on optimization of cover glass for photovoltaics [3, 4], iii) initial results on how to provide both anti-reflective and anti-soiling properties, iv) results on broadband antireflective coatings for solar thermal energy [5], and v) other promising concepts. At last, will some perspective of matters for further research be presented.

[1] J. Deubener, et al., Glasses for solar energy conversion systems. Journal of the European Ceramic Society, 2009. 29(7): p. 1203-1210. DOI: http://dx.doi.org/10.1016/j.jeurceramsoc.2008.08.009.

[2] M. Teitel, et al., Greenhouse and screenhouse cover materials: literature review and industry perspective. Acta Horticulturae, 2018. 1227: p. 31-44. DOI: https://doi.org/10.17660/ActaHortic.2018.1227.4.

[3] B.L. Allsopp, et al., Towards improved cover glasses for photovoltaic devices. Progress in Photovoltaics: Research and Applications, 2020. 28(11): p. 1187-1206. DOI: https://doi.org/10.1002/pip.3334.

[4] P. Sundberg, et al., Simultaneous chemical vapor deposition and thermal strengthening of glass. Thin Solid Films, 2019. 669: p. 487-493. DOI: https://doi.org/10.1016/j.tsf.2018.11.028.

[5] E. Zäll, et al., Aerosol-based deposition of broadband antireflective silica coating with closed mesoporous structure. Solar Energy Materials and Solar Cells, 2023. 250: p. 112078. DOI: https://doi.org/10.1016/j.solmat.2022.112078.