Are Technological Developments Improving the Environmental Sustainability of Photovoltaic Electricity?
Blanco, Carlos Felipe ; Cucurachi, Stefano ; Peijnenburg, Willie J.G.M. ; Beames, Alistair ; Vijver, Martina G. - \ 2020
Energy Technology (2020). - ISSN 2194-4288
environmental impacts - life-cycle assessments - photovoltaics - solar - sustainability
Innovation in photovoltaics (PV) is mostly driven by the cost per kilowatt ratio, making it easy to overlook environmental impacts of technological enhancements during early research and development stages. As PV technology developers introduce novel materials and manufacturing methods, the well-studied environmental profile of conventional silicon-based PV may change considerably. Herein, existing trends and hotspots across different types of emerging PV technologies are investigated through a systematic review and meta-analysis of life-cycle assessments (LCAs). To incorporate as many data points as possible, a comprehensive harmonization procedure is applied, producing over 600 impact data points for organic, perovskite (PK), dye-sensitized, tandem, silicon, and other thin-film cells. How the panel and balance of system components affect environmental footprints in comparable installations is also investigated and discussed. Despite the large uncertainties and variabilities in the underlying LCA data and models, the harmonized results show clear positive trends across the sector. Seven potential hotspots are identified for specific PV technologies and impact categories. The analysis offers a high-level guidance for technology developers to avoid introducing undesired environmental trade-offs as they advance to make PV more competitive in the energy markets.
Fluorine-containing triphenylenes. Liquid crystalline properties and surface ordering
Umesh, C.P. ; Marcelis, A.T.M. ; Zuilhof, H. - \ 2014
Liquid Crystals 41 (2014)12. - ISSN 0267-8292 - p. 1911 - 1922.
fluoroalkylated side-chains - hexagonal columnar mesophase - homeotropic alignment - mesomorphic properties - carrier mobilities - behavior - semiconductors - phthalocyanine - photovoltaics - transistors
The synthesis and liquid crystalline properties of two novel series of triphenylenes with 4 or 5 pentafuoropentyloxy tails and 1 or 2 alkoxy tails of varying length are reported. All compounds form wide-range hexagonal columnar phases. The isotropisation temperatures and the corresponding enthalpy changes for the compounds with 4 or 5 fluorinated tails are higher than for the compounds with 6 alkoxy tails, and also higher than for compounds with 6 fluorinated tails. These results indicate that the best ordering is obtained for compounds with a mix of fluorinated and non-fluorinated tails. With increasing length of the alkyl tails in HAT compounds with 4 or 5 fluoroalkoxy tails, the isotropisation temperatures decrease and the d-spacings as observed by XRD increase. All fluorocontaining compounds have a strong tendency for spontaneous homeotropic alignment on surfaces, both hydrophilic and hydrophobic.