Photovoltaic cells generate electricity from sunlight, typically by means of a p-n junction semiconductor material. Their ability to generate energy from a free fuel, using no moving parts, creating no noise or on-site emissions, with minimal maintenance in a highly predictable and reliable fashion, is unparalleled. Application of the technology is modularised and deployment can take place where energy is most valuable: at the point of use. In a world of widespread energy inequality, dominated by unbalanced and typically centralised energy systems, photovoltaics’ time has come.
Knowledge of photovoltaic technology has progressed rapidly over the last half-century. Although the photovoltaic effect was discovered in the 1800’s, the silicon solar cell was first developed in a useful form by the Bell Telephone Laboratories in 1954. This wafer-based silicon cell has become the mainstay of the solar industry since that time and has certainly led the charge to production levels of a giga-watt per annum scale (reached in 2004). The global bottleneck in supply of high purity solar grade silicon experienced in recent years highlighted the point that this technology is not likely to lead the charge to a world with a terra-watt of installed photovoltaic capacity.
Photovoltaics is, however, not without its limits. Just as the amount of oil left in the earth’s crust is limited, there is only a finite amount of energy available from sunlight. Thankfully, unlike oil and other fossil fuels, this amount of energy is highly predictable, enormous on a global scale and quite obviously, constantly replenished.
This is an edited excerpt from Opportunities for Vehicle Integrated Photovoltaics.
If you are interested in buying an in-depth book on the topic I suggest Applied Photovoltaics from Amazon.