JNTU B.Tech III NON-CONVENTIONAL ENERGY SOURCES Previous Question Paper (August/September - 2021 - R18)

Solar power is a clean, renewable energy source, but its lifecycle involves several environmental considerations. During the manufacturing of photovoltaic (PV) cells, hazardous materials such as cadmium, lead, and silicon tetrachloride are used, requiring strict disposal protocols to prevent soil and water contamination. The extraction of raw materials like silver, indium, and tellurium involves mining activities that can lead to habitat destruction and high energy consumption. At the operational stage, large-scale solar farms require significant land area, which may lead to land-use conflicts, loss of biodiversity, and potential micro-climate changes due to the albedo effect. However, solar power significantly reduces greenhouse gas emissions and air pollutants compared to fossil fuel-based generation, contributing to climate change mitigation. Finally, the end-of-life management of solar panels presents a challenge, necessitating efficient recycling programs to recover valuable materials and prevent electronic waste accumulation in landfills.

A Pyrheliometer is designed to measure direct beam solar radiation at normal incidence, typically by tracking the sun, whereas a Pyranometer measures global solar radiation, which includes both direct and diffuse components, from a 180-degree field of view.

The Angstrom type pyrheliometer operates on the principle of electrical compensation. It consists of two identical thin manganin strips, one of which is exposed to solar radiation while the other is shielded. The exposed strip absorbs solar energy and rises in temperature, while the shielded strip is heated by an electric current until its temperature matches that of the exposed strip. The temperature balance is monitored by thermocouples attached to the back of the strips. When the temperatures are equal, the solar radiation intensity is calculated based on the electrical power supplied to the shielded strip, using the principle that the heat generated by the current equals the heat absorbed from the solar radiation.