Monthly Archives: September 2013


SOLAR TECHNOLOGY AND ELECTRICITY FROM SUN ENERGY

Introduction

It is now clear that the fossil-fuel era of non-renewable resources is gradually coming to an end. The renewable sources of energy derived from the Sun are one of the promising options. Solar energy can be used both directly and indirectly. It can be used directly in a variety of thermal applications like heating air or water, drying, distillation and space heating etc. A second way in which solar energy can be used directly is through the photovoltaic effect, in which it is converted to electrical energy.

Electricity from renewable energy (RE) sources is been seen as more viable solution for energy deficiency, energy security and for social development. Among the many RE technologies and sources, electricity produced directly from the sun using solar photovoltaic (SPV) technology is gaining interest from government and investments from private enterprises. The solar PV technologies are now increasingly seen as major electricity source for Indian scenario.

Solar PV technologies

Converting light to electricity Solar PV is a semiconductor device which converts sunlight directly into electricity. The operation of light to electricity conversion requires a built‐in electric field, normally obtained by making PN junction or PiN junction structures. A solar PV panel or a solar PV module when exposed to sunlight generates voltage and current at its output terminal. This voltage and current can be used for our electricity requirements. The amount of electricity a solar PV module can generate depends on the amount of sunlight falling on it. The higher is the intensity of the sunlight the more will be the electricity generated from it. When no sunlight falls on a solar PV module, no electricity is generated.

History of Solar energy conversion

Historically, it has been about 50 years since the first operational silicon solar cell was demonstrated. However, the last 10 years have seen large improvements in the technology, with the best confirmed cell efficiency now being over 24%, the main drivers being the improved electrical and optical design of the cells.Improvements in the electricity production area include improved activation of contact and surface regions of the cells and a reduction in the volume of heavily doped material within the cell. Optically, reduced reflection and improved trapping of the light within the cell have had a large impact. These features have increased silicon cell efficiency to a confirmed value of over 24.7%. Together with technical progress there is support from the governments for solar PV technologies around the world. Overall effect is significant growth of the PV technology.

SPV is here to stay and the faster we accept its utility, the easier it will be to solve much of our current electricity and energy deficiency problem.

Source courtesy: Wikipedia