Search

While solar PV (photovoltaic) cells are promising for clean energy production, their mass deployment is hindered by production costs, material availability, and toxicity. Two materials that can overcome these challenges and replace today's CdTe (cadmium telluride) and CIGS (copper indium gallium diselenide) based PV cells are Zn3P2 (zinc phosphide) and CZTS (copper zinc tin sulfide). A cradle to gate life cycle assessment was conducted to understand the environmental impacts from these technologies. The impacts from Zn3P2 and CdTe were similar and lower than the impacts from CZTS and CIGS. While CdTe has the toxic Cd element, the ecotoxicity impact from material acquisition and processing was higher for Zn and P than for CdTe. In CIGS, the ecotoxicity impact came mainly from Ga and would be significantly reduced if CZTS were to replace CIGS in the commercial market. For all four thin films studied, the contribution of raw materials to total impact was much lower than the impact coming from electricity consumption during the manufacturing stage. Therefore, to reduce environmental impact, future PV technology development should focus more on the process improvement. The manufacturing stages that contributed most to the impact were the absorber layer for CIGS and CZTS and the substrate cleaning for CdTe and Zn3P2.

This article compares the economic development of Shanghai and Hong Kong over the last 150 years in a bid to uncover why Shanghai fell behind Hong Kong despite its head start as an international financial center in the 1920s. It then examines whether Shanghai might eventually catch up with Hong Kong in terms of standard of living, technological innovation, infrastructure, creativity and social cohesion. Both cities were faced with new opportunities after the global financial crisis, and both are aiming at present to extend their capital markets. Although, since the 1990s, economic reforms have given Shanghai a breath-taking makeover, Hong Kong’s fiscal architecture is still more business-friendly. Hong Kong also possesses a higher degree of global exposure, and more efficient and transparent equity markets. Notwithstanding Shanghai’s “open-door” policy and lower cost of living, Hong Kong has proven more attractive to global talent. But Shanghai and Hong Kong will cash in on China’s rise in different ways, and the gap between two cities is therefore likely to narrow. Local Policy-makers are best advised to design complimentary business environments rather than trying to out-perform the other city in its area of strength.