Q1: Which of the following is an unconventional source of energy ?

ANS:D - Solar power

Solar power, also known as solar energy, refers to the conversion of sunlight into electricity or heat. It is harnessed using various technologies, primarily solar photovoltaic (PV) panels and solar thermal systems.

1. Solar Photovoltaic (PV) Panels: Solar PV panels consist of semiconductor materials, such as silicon, that convert sunlight directly into electricity through the photovoltaic effect. When sunlight strikes the surface of a solar panel, it excites electrons in the semiconductor material, generating an electric current. This electricity can then be used to power homes, businesses, and other applications.
2. Solar Thermal Systems: Solar thermal systems utilize sunlight to generate heat, which can be used directly for heating water or air, or to produce steam for electricity generation through steam turbines. There are several types of solar thermal systems, including:
   • Flat-plate collectors: These systems consist of a flat, insulated metal box with a glass or plastic cover and a dark-colored absorber plate inside. Sunlight heats the absorber plate, which then transfers the heat to a fluid (such as water or antifreeze) flowing through tubes or channels in the collector.
   • Concentrated solar power (CSP): CSP systems use mirrors or lenses to concentrate sunlight onto a small area, typically a receiver or a heat transfer fluid. The concentrated sunlight produces high temperatures, which are used to generate steam to drive a turbine for electricity generation.

Solar power offers several advantages, including:

• Renewable: Solar energy is abundant and inexhaustible, making it a sustainable source of power.
• Clean: Solar power generation produces minimal greenhouse gas emissions and pollution compared to fossil fuels, contributing to efforts to combat climate change and improve air quality.
• Low Operating Costs: Once installed, solar PV systems have relatively low operating and maintenance costs, as sunlight is free and abundant.
• Decentralized: Solar panels can be installed on rooftops or in remote areas, enabling decentralized energy generation and reducing reliance on centralized power plants.

Despite these benefits, solar power also faces challenges, including intermittency (variation in sunlight availability), energy storage limitations, and upfront installation costs. However, ongoing technological advancements and decreasing costs are driving increased adoption of solar energy worldwide.