Solar power is widely promoted as a important means to reduce harmful environmental impacts of electricity generation, particularly the avoidance of climate changing greenhouse gas (GHG) emissions. Governments worldwide support renewable energy by the mandating of renewable portfolio standards, tax incentives and feed-in tariffs. Due in part to government support and also to large reductions in module costs, the global installed capacity of solar photovoltaic (PV) systems is increasing rapidly.
The energetic performance of solar cells is dependent on a number of factors: efficiency, lifetime, capacity factor, and energetic cost of cell manufacture. There is a large drive to boost the efficiency of PV cells via a number of techniques including: improved light trapping; high efficiency materials, such as gallium arsenide (GaAs); multiple-junction cells to capture more of the sunlight spectrum; multiple exciton generation and quantum dot cells; plasmonic and hot carrier cells. Previous studies have highlighted both the energetic and climate benefits of PV systems with low cumulative electricity demand (CEeD), i.e. low embodied energy.
This study explores the landscape of energetic performance of a variety of different PV technologies to identify potential benchmarks for research and technology development.