Linking nanotechnology to gigawatts: Creating building blocks for smart PV modules

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Abstract

Cost reduction, expressed commonly as a unit cost/Wp on the level of solar cells, PV modules and systems, is the overarching theme of the major part of worldwide activities in the field of photovoltaics. Obviously, this is the condition sine qua non to be met for reaching economical viability of solar photovoltaic energy. We already outlined 1 earlier that a number of nanotechnologies developed for advanced Si-based nanoscale CMOS transistors might also be very useful for the race toward crystalline Si solar cells with higher efficiency and lower cost. The focus on this cost parameter might, however, obscure the growing need to add more functionality to the PV system if photovoltaic energy is to play an important role in the electricity generation scenarios of the future 2. In the view of the authors much of this added functionality could be integrated at the module or even within the module by using a number of microscale and nanoscale technologies. This added functionality on PV-module level might in first instance aim at an increase of energy yield by adding electronic components allowing to minimize the effect of shadowing losses by allowing a certain degree of reconfigurability of the PV module. Eventually, this might also reach out further by integrating the DC–AC inverter with the module (allowing to reduce DC losses) and in the end even other components integrating control and interaction functions with the electricity grid. In this paper we describe the philosophy behind the concept of the “Smart PV module” as well as two crucial technologies to realize this concept: the embedding technology for cells and components in the so-called U module and the development of a low-cost technology for reliable high-power components based on GaN-on-Si, enabling the high-frequency switching transistors in the DC–DC or DC–AC converters or the low-loss switches in a “reconfigurable” U module. Besides the well-spread conviction that nanotechnological aspects will lead to advances in terms of solar cell performance and lower cell costs, the message which we would like to convey is the fact that the development of miniaturized components using advances in micro- and nanotechnology are also very likely to affect the development of the “smart PV module” concept, providing ground for the statement “linking nanoscale to gigawatts.” Copyright © 2010 John Wiley & Sons, Ltd.

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