What Is Renewable Energy - Its Introduction, Types, Applications, Advantages, Disadvantages, Economics, Future Growth 

Introduction :-

Renewable energy is energy that is generated from natural resources that can be replenished over time, such as sunlight, wind, rain, and geothermal heat. These energy sources are sustainable and can be replenished naturally, unlike fossil fuels, which are finite and contribute to climate change.

This includes Solar energy is referred to as renewable or sustainable energy because it will be available as long as the sun continues to shine. Estimates for the remaining life of the main stage of the sun are another 4 to 5 billion years. The energy from the sun, electromagnetic radiation, is referred to as insolation. The other main renewable energies are wind, bioenergy, geothermal, hydro, tides, and waves. Wind energy is derived from the uneven heating of the surface of the Earth due to more heat input at the equator with the accompanying transfer of water and thermal energy by evaporation and precipitation. In this sense, rivers and dams for hydro energy are stored solar energy. Another renewable energy is geothermal energy due to heat from the Earth from decay of radioactive particles and residual heat from gravitation during formation of the Earth. Volcanoes are fiery examples of geothermal energy reaching the surface from the interior, which is hotter than the surface.

Tidal energy is primarily due to the gravitational interaction of the Earth and the moon. Overall 14% of the world’s energy comes from bioenergy, primarily wood and charcoal but also crop residue and even animal dung for cooking and some heating. This contributes to deforestation and the loss of topsoil in developing countries. Production of ethanol from biomass is now a contributor to liquid fuels for transportation, especially in Brazil and the United States. In contrast, fossil fuels are stored solar energy from past geological ages. Even though the quantities of oil, natural gas, and coal are large, they are finite, and for the long term of hundreds of years, they are not sustainable.

Here are the main types of renewable energy:

1. Solar Energy :-

Solar energy is one of the most important renewable energy sources that has been gaining increased attention in recent years. Solar energy is plentiful; it has the greatest availability compared to other energy sources. The amount of energy supplied to the earth in one day by the sun is sufficient to power the total energy needs of the earth for one year. Solar energy is generated from the sun's rays, either through photovoltaic (PV) panels or solar thermal systems. PV panels convert sunlight into electricity. Solar energy is clean and free of emissions, since it does not produce pollutants or by-products harmful to nature. The conversion of solar energy into electrical energy has many application fields. Residential, vehicular, space and aircraft, and naval applications are the main fields of solar energy.

2. Wind Energy :-

Wind is the airflow that consists of many gases in the atmosphere of the earth. Rotation of the earth, uneven heating of the atmosphere, and the irregularities of the ground surface are the main factors that create winds. Wind turbines capture the kinetic energy of winds and convert it into a usable form of energy. The kinetic energy of winds rotates the blades of a wind turbine. The blades are connected to a shaft. The shaft is coupled to an electric generator. The generator converts the mechanical power into electrical power. Wind turbines are typically installed on land or in the ocean, and can be used to power homes, businesses, or industries.

3. Hydro Energy :-

Hydro energy is generated from the movement of water, such as from rivers, oceans, or tidal currents. The energy in water can be potential energy from a height difference, which is what most people think of in terms of hydro; the most common example is the generation of electricity (hydroelectric) from water stored in dams. However, there is also kinetic energy due to water flow in rivers and ocean currents. Finally, there is energy due to tides, which is due to gravitational attraction of the moon and the sun, and energy from waves, which is due to wind.

4. Geothermal Energy :-

Geothermal energy is generated from the heat of the Earth's core. Hot water or steam from underground reservoirs is used to power turbines, generating electricity. With reservoir temperatures of 120–370°C, hot water or steam can be used to generate electricity in a conventional power plant. Hot water that is trapped in underground reservoirs within 1 to 6 km of the surface can be tapped by drilling. Geothermal energy is not renewable in the same sense as solar, wind, and hydro energy, and the average heat flow of the Earth is a thousand times less than the low-density solar insolation. Another major difference is that solar and wind energy are variable on short time periods, and hydro is variable by season; however, geothermal energy only declines as heat is taken out, with lifetimes of 100 or more years.

5. Biomass Energy :-

Biomass energy is a renewable energy source that uses organic materials to produce heat, electricity, or converted into biofuels for transportation. Biomass energy is generated from organic matter, such as Plants and wood products, Agricultural crops and residues, Animal waste and manure, Food processing waste and Municipal solid waste.

6. Hydrogen Energy :-

Hydrogen energy is generated from the reaction of hydrogen with oxygen, potentially produced from renewable energy sources. Hydrogen is a clean fuel that, when consumed in a fuel cell, produces only water. Once hydrogen is produced as molecular hydrogen, the energy present within the molecule can be released, by reacting with oxygen to produce water. This can be achieved by devices called fuel cells. In a fuel cell, hydrogen energy is converted directly into electricity with high efficiency and low power losses. When it “burns” in air releasing that stored energy it simply combines with oxygen to produce water again. Hydrogen can be produced from a variety of domestic resources, such as natural gas, nuclear power, biomass and by splitting water using renewable solar or electrical energy. Hydrogen can be used as a fuel for transportation, power generation, or industrial processes.

Economics :-

Energy is a fundamental input for economic systems. Current economic activity depends overwhelmingly on fossil fuels including oil, coal, and natural gas. These fuels are non-renewable. Renewable sources such as hydroelectric, wind, and solar power currently provide less than 10% of global energy.

Many sources of renewable energy are available, and have been used for centuries. Most renewables are less available and/or have higher costs than fossil fuels used in the recent past. The costs of renewable energy resources are attributable in part to inherent characteristics, particularly their low net energy ratios, intermittent availability, and capital intensity. we should be looking at life-cycle costs rather than our ordinary way of doing business, low initial costs. Life-cycle costs refer to all costs over the lifetime of the system.

“We cannot have a clean environment because it is uneconomical.” The thought here is that renewable energy is not economical in comparison to coal, oil, and natural gas. We must be allowed to continue our operations as in the past because if we have to install new equipment to reduce greenhouse gas emissions, we cannot compete with other energy sources, and finally we will have to reduce employment

The advantages of renewable energy :-

• Water conservation: Most renewable energy sources require very little water to operate, conserving this precious resource. Wind turbines and photovoltaic panels do not need water for the generation of electricity, in contrast to steam plants fired by fossil fuels and nuclear power.
• Renewable energy sources like solar, wind, and hydroelectric power do not emit greenhouse gases, contributing less to climate change. Renewable energy can improve public health and quality of life by reducing air pollution from fossil fuels.
• The renewable energy industry is creating new job opportunities and driving economic growth.
• The cost of renewable energy is decreasing over time, making it more competitive with fossil fuels.
• Renewable energy can reduce reliance on imported fossil fuels, improving energy security and reducing trade deficits.
• Renewable energy sources like solar and wind can provide reliable and resilient energy supply, reducing the risk of power outages.
• Renewable energy sources can reduce dependence on a single energy source, improving energy security and reducing the risks associated with price volatility.
• Renewable energy sources can reduce the risk of price volatility associated with fossil fuels.
• Renewable energy sources like solar and wind have low maintenance costs, reducing the overall cost of energy production.
• Renewable energy is driving technological innovation, improving energy efficiency and reducing costs.

The disadvantages of renewable energy :-

• Renewable energy sources like solar and wind are intermittent, meaning they are not always available. Natural sources of energy cannot be conjured up in each moment that we need energy, some days the wind does not blow, and the sun does not shine. Hydropower may be unavailable during drought periods, and biomass crops experience crop failures
• Renewable energy sources can be less reliable than traditional fossil fuel-based power plants. By their nature, most renewable energy supplies cannot be matched to demand as easily as fossil fuels.
• Building out renewable energy infrastructure, such as transmission lines and storage facilities, can be costly. Cost of renewable energy is decreasing, the upfront investment can still be significant.
• Large-scale renewable energy projects, such as wind farms and solar parks, require significant land areas.
• Renewable energy projects can have environmental impacts, such as bird strikes at wind turbines and habitat disruption.
• Renewable energy sources require energy storage solutions to ensure a stable energy supply. Energy storage solutions, such as batteries, can be expensive and inefficient.
• Renewable energy sources can be difficult to integrate into the existing grid infrastructure.
• Renewable energy technologies, such as solar panels and wind turbines, have efficiency limitations.
• Renewable energy technologies require materials, such as rare earth metals and silicon, which can be expensive and have environmental impacts.

Growth of Renewable Energy :-

• Renewable energy is becoming increasingly cost-competitive with fossil fuels, leading to growing adoption rates.
• Advances in technology are improving the efficiency and reducing the costs of renewable energy systems.
• Innovations in energy storage, such as batteries and hydrogen fuel cells, are helping to address the intermittency challenge.
• Efforts to modernize the grid, including the integration of smart grid technologies and energy storage, are helping to support the widespread adoption of renewable energy.
• International cooperation and agreements, such as the Paris Agreement, are helping to drive the global transition to renewable energy.