SOLAR CELLS

Solar Cells

Solar Cells

Introduction

Solar Energy is an alternative form of fuel that involves the transformation of the thermal energy of the sun into electricity. Environmental experts encourage the adaptation of regulations that need promote the utilization of solar and other forms of renewable energies (Norman & Kraft, 2009, pp.91).

Solar Energy

Solar cells use a semiconductor to convert the solar energy of sunlight into electricity via the photovoltaic effect. Individual cells are assembled in order to form solar panels and arrays. First observed by French physicist Alexandre-Edmond Becquerel, son of electricity pioneer Antoine Cesar Becquerel, as a teenager in 1839, the photovoltaic effect is the process that produces voltage or electric current in a material that has been exposed to electromagnetic radiation (such as light).

History of Solar Cells

American inventor Charles Fritts built the first solar cell in 1883, who coated selenium (a semiconductor) with a thin layer of gold. The solar cell worked but had efficiency of only about 1 percent, making it impossible to generate enough electricity to recover the cost of the materials except over a very long period. Improvements to solar cells in the mid-20th century brought efficiency up to 5 percent. This rate climbed gradually, with many cells on the 21st-century market exceeding 20 percent efficiency (the most efficient are over 40 percent) (Tyler & Spoolman, 2010, pp.23).

Working Mechanism

Solar cells are connected in modules, which are connected in an array. There are a number of types of solar cells, often referred to by the material used to make their thin film.

Figure 1: Structure of a Photovoltaic Cell [courtesy: U.S. Department of Energy]

Thin film solar cells include thin-film silicon (the same material, just thinner, used in the 1990s), cadmium telluride (CdTe), and copper-indium selenide (CIGS), which vary in efficiency and cost. The most competent cells are multi-junction devices that use multiple thin films, each of which is most efficient at a certain portion of the electromagnetic spectrum. The cost of gallium and germanium has risen as demand has increased for multi-junction solar cells using gallium arsenide (GaAS), gallium indium phosphide (GaInP), and germanium thin films (Graetzel, 2007, pp.78).

Life-Cycle Impacts of Solar Panels

The Life-cycle of a Solar Panel involves for main stages: Materials and inputs, production and manufacturing, its usage and lastly its disposal.

Whilst Solar panels do have a few negative impacts, including the energy consumption and emissions related to power generation and panel production, and the release of a few hazardous by-products, their positive impacts are far greater than the negative impacts of their life cycle.

Positives

Emission-free Energy

The greatest positive of solar panels is the production of 100% emission free energy, ensuring a reduction in pollution by 89% as compared to other methods of energy generation.

Energy Output Area

The solar power plants offer the same area of energy output if not better than the using the fossil fuels and coal mining.

Efficiency

The solar panels offer great efficiency generating as much as 10-15 times the energy used in their production.

Environment Friendly

The solar panels ensure great potential to improve the climatic conditions since they reduce the carbon release to as much as 25 units compared to ...