What are the Various Types of Renewable Energy?
Renewable energy is practically unlimited. It is the type of energy that we cannot replenish by utilising. We are surrounded by sources of renewable energy all around – this includes wind, solar, geothermal, ocean currents, etc.
All the types of renewable energy stand in sharp contrast to fossil fuels. Fossil fuels are finite and contribute the most to greenhouse gas emissions. In contrast, renewable energy such as solar energy is environment friendly and infinite.
Renewable energy is also known as green or clean energy as it ensures sustainability. It helps prevent the depletion of natural resources to conserve them for future generations. Renewable energy is a natural source of power. The carbon footprint it brings is zero or almost near zero.
What is Renewable Energy?
Here are the 7 most important forms of renewable energy:
1. Solar Energy
Solar energy is the sun’s radiation which can be used to produce electricity, create heat and catalyse chemical reactions. It is the most abundant form of energy. Photovoltaic panels and concentrating mirrors are most commonly used to harness solar electricity.
As per Britannica Encyclopedia, the Earth daily receives sunlight which is about 2 lakh times its daily electricity generation capacity. Theoretically, it is possible to power the needs of all countries by using solar energy. However, there are practical constraints related to geopolitics, technology, and financing of solar projects.
According to the Ministry of New and Renewable Energy (MNRE), approximately 5 million GWh of solar energy is incident on the Earth annually. Some of the largest solar parks in the world are in India.
Benefits of Solar Energy:
- The solar panels have a lifespan of 25-30 years. It makes installing a solar system an excellent long-term investment option.
- The technology of solar panels is developing rapidly. It promises to reduce their cost and improve their efficiency.
- You can save on your electricity bills by installing a solar system.
- Countries receiving abundant sunlight can set up solar parks to generate clean energy and combat global warming.
If you are installing a solar system for your home or office building, you must be willing to buy the best solar panels available in India.
Limitations of Solar Energy:
- Solar energy cannot be produced at night, unlike wind or ocean energy.
- Investing in solar systems, both for domestic and commercial purposes, involves a significant investment.
- Space constraints can limit the capacity of a solar system.
- Harmful chemicals in solar panels can hurt the environment upon disposal.
- If you relocate, it will be expensive and time-consuming to uninstall the solar system.
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2. Wind Energy
Energy harnessed from the wind is called wind energy. Wind turbines convert the kinetic energy of the wind into electricity.
Wind turbines are best suited to large-scale commercial installations. The availability of strong and constant winds is a major criterion for their installation. Wind turbines are usually located in remote locations with thin population densities.
As per the MNRE report on wind power, India has a wind power potential of 695.50 GW at 120 meters and 1,163.9 GW at 150 meters above ground level.
The penetration of wind energy is projected to increase at a compounded annual growth rate or CAGR of 8.34% between 2024 and 2029 (Statista report on worldwide wind energy).
Benefits of Wind Energy:
- The wind industry has the potential to create a lot of jobs.
- Wind power can be generated 24 x 7.
- No water is required for running and maintaining wind turbines.
- Wind energy production has a low operating cost.
Limitations of Wind Energy:
- Wind turbines can hurt the local avian species.
- Wind turbines cause noise pollution.
- It is difficult to install wind turbines in urban areas.
3. Geothermal Energy
Geo means ‘earth’ and thermal means ‘heat’ in Greek. Geothermal energy is the heat energy within the earth. The radioactive decay of particles in the Earth’s core creates geothermal energy. One of the most common examples of geothermal energy is hot water from the ground.
Though the amount of geothermal energy within the Earth vastly exceeds humanity’s requirements, harnessing it is a difficult task. Finding out where a geothermal resource is located and then setting up the infrastructure to utilise it is challenging.
Benefits of Geothermal Energy:
- The CO2 emissions by a geothermal plant are much less compared to a fossil fuel-based thermal plant.
- It is available 24 x 7.
- Requires much less space compared to solar parks and wind turbines.
- Geothermal systems have a long lifespan and require minimal maintenance.
Limitations Geothermal Energy:
- The initial cost of installing a geothermal plant is high.
- Certain sources of geothermal energy may cool down after some time.
- Setting up geothermal plants can lead to earthquakes.
4. Hydropower
India’s hydropower capacity is expected to increase from 42 GW today to 67 GW by 2031-32 (PIB Report). Hydropower is generated by harnessing the energy of moving water to generate electricity. Dams, streams and rivers are sources of hydropower. Turbines and generators in hydropower facilities convert the kinetic energy of moving water into electricity which is then sent to a power grid.
Here’s a video explaining how hydropower works:
Benefits of Hydropower:
- Hydropower’s return on investment makes it a relatively inexpensive source of energy.
- Hydropower reservoirs such as dams can be used as sources of fresh and clean water.
- It is a clean source of energy.
- Hydropower systems can help in flood control.
Limitations of Hydropower:
- It is expensive to build hydropower infrastructure.
- Infrastructure such as dams can negatively affect the local flora and fauna, for example affecting the migration patterns of local fishes.
- Power production can fall due to a drought.
5. Ocean Energy
Ocean energy or marine energy sources include tides, waves, and ocean currents. Ocean energy is also known as marine energy.
One of the ways to generate ocean energy is to use the temperature difference between the hot surface of an ocean and its cooler interiors. The process for generating electricity from this temperature difference is called ocean thermal energy conversion.
Benefits of Ocean Energy:
- As over 70% of the Earth is covered by oceans, there are plenty of sources for generating ocean energy.
- It is environmentally much cleaner and safer than fossil fuels or geothermal energy.
- It is inexhaustible and available 24 x 7.
Limitations of Ocean Energy:
- Noise and vibrations from ocean energy infrastructure can negatively impact marine organisms.
- Harnessing ocean energy requires highly expensive infrastructure.
- Technology for harnessing ocean energy is evolving at a very slow pace.
6. Bioenergy
You can generate bioenergy from biomass such as wood, dung, charcoal and manures. This type of renewable energy is popularly used in rural areas in developing countries. In addition, other sources of biomass include crops, trees, agricultural residues, organic waste streams and forestry.
As per a report by the Comptroller and Auditor General of India, over 70% of India’s population still relies on biomass to meet its energy requirements. Its popularity can be traced to its affordability and abundance of biomass in the country.
Benefits of Bioenergy:
- The abundance of biomass makes bioenergy highly affordable.
- It is a carbon-neutral source of energy.
- Harnessing bioenergy helps in waste reduction.
Limitations of Bioenergy:
- It is expensive to produce bioenergy.
- Bioenergy plants require a lot of area.
- Though it is carbon-neutral, biomass releases carbon dioxide into the atmosphere.
- Burning biomass releases several greenhouse gases into the atmosphere.
7. Hydrogen Fuel Cells
Hydrogen fuel cells generate electricity by combining hydrogen and oxygen atoms. The reaction produces three products: electricity, water, and heat. Fuel cells can be used for small-scale as well as large-scale applications.
Hydrogen fuel cells have a higher efficiency than combustion engines. They are mostly quiet as they don’t have any moving components. Here’s a diagrammatic representation of a hydrogen fuel cell:
Source: National Energy Education Project
Benefits of Hydrogen Fuel Cells:
- They are more efficient and powerful than hydrogen fuel cells.
- Hydrogen fuel cells have little or no emissions compared to combustion engines.
- Hydrogen fuel cells don’t generate noise pollution.
Limitations Hydrogen Fuel Cells:
- Developing hydrogen fuel cells is highly expensive.
- Extracting hydrogen from water or fossil fuels demands tremendous energy.
- Storage and transportation of hydrogen is a complex process.
Renewable energy is crucial for meeting today’s energy needs. Most have them have minimal to zero carbon footprint. The Paris Agreement of 2015 led to an international consensus to limit global temperature increase to 1.5 degrees Celsius above pre-industrial levels. Countries such as India are harnessing several types of renewable energy to meet their international climate change targets.
Frequently Asked Questions
Renewable energy is a form of energy which is replenished before it is exhausted, thus making it practically limitless.
Important types of renewable energy include solar electricity, hydropower, and power from a hydrogen fuel cell.
Fossil fuels such as oil, natural gas, and coal are major non-renewable energy sources.
Inexhaustibility, reduced emissions, and increased energy security are some of the benefits of renewable energy.
