What Are The 5 Most Used Renewable Sources Of Energy?

Renewable energy comes from natural sources or processes that are constantly replenished. Some of the most common renewable energy sources are solar, wind, water, biomass, and geothermal heat. There has been a global shift towards increasing the share of renewable energy to address climate change and meet rising energy demands in a sustainable way. According to the International Energy Agency, the share of renewables in global electricity generation jumped to 29% in 2019 from 24% in 2015.

This article will provide an overview of the top 5 most used renewable energy sources today. Understanding the current state of renewable energy is important as the world transitions to clean energy to secure our energy future and mitigate climate change.

Table of Contents

#1 – Hydroelectric

Hydroelectric power is a renewable energy source that uses the natural water cycle to generate electricity. It is the most widely-used form of renewable energy in the world, accounting for over 20% of global electricity generation in 2020 (Source: https://valuer.ai/blog/how-can-we-transition-into-renewable-energy). Hydroelectric power plants capture the energy from flowing water to turn turbines and generators that produce electricity.

There are three main types of hydropower facilities: impoundment, diversion, and pumped storage. Impoundment facilities utilize dams to store water in reservoirs. As water is released from the reservoir, it flows through turbines to generate electricity. Diversion facilities channel a portion of a river through a canal or pipeline to spin turbines. Pumped storage facilities pump water uphill into a reservoir during periods of low electricity demand and release it downhill through turbines when demand is high.

The pros of hydroelectric power include its renewable, emissions-free nature and cost effectiveness once facilities are constructed. It also offers flexibility to meet peaks in electricity demand. However, the cons are its high upfront costs and impacts on fish migration and river ecosystems from damming. There is also often displacement of communities and habitats when reservoirs are flooded.

#2 – Wind

Wind power has emerged as one of the fastest growing renewable energy sources in the world. According to IFPEN, wind power is currently the second most used renewable energy source globally after hydropower, supplying over 8% of electricity in some countries.

Wind turbines convert the kinetic energy in wind into mechanical power that can generate electricity. The turbines typically have two or three blades that spin as the wind blows over them. The rotational motion turns a shaft connected to a generator to produce electricity.

Wind power can be generated both onshore and offshore using wind turbines. Onshore wind farms are located on land, while offshore wind farms are installed in bodies of water, usually oceans or lakes. Offshore wind tends to be stronger and more consistent compared to onshore wind. However, offshore wind farms are more expensive to construct.

Some of the pros of wind power include its abundance as a renewable resource, low operating costs once installed, and zero emissions. The cons include intermittency issues, potential noise pollution, large land footprint for onshore turbines, and threats to wildlife such as birds.

#3 – Solar

Solar energy is harnessed in two main ways – through photovoltaic (PV) panels that convert sunlight into electricity, and solar thermal systems that use the sun’s heat for water heating, space heating, or electricity generation. PV panels are made of semiconducting materials like silicon that absorb photons from sunlight and release electrons, generating a flow of electricity. Solar thermal systems use mirrors or lenses to concentrate sunlight that heats up a transfer fluid, which is then used to produce steam to drive a turbine for electricity or provide heat.

Solar energy has become increasingly affordable and accessible. The cost of solar panels has dropped over 70% in the last decade, and continuing innovations aim to improve efficiency and lower costs further. Solar has huge potential as an abundant and renewable energy source, capable of meeting a significant portion of the world’s electricity needs. In some regions it is already price competitive with conventional power. Solar also enables a distributed energy model, allowing households and businesses to generate their own emission-free electricity.

However, solar power can have drawbacks. PV efficiency is limited by weather and climate conditions, requiring storage solutions for when the sun isn’t shining. Large-scale solar power plants can be land intensive. There are emissions associated with solar panel manufacturing, transport and installation. Disposal and recycling of old solar panels requires proper management. Overall though, solar energy offers significant environmental and sustainability benefits.

Sources:
https://www.energy.gov/eere/solar/how-solar-photovoltaic-works
https://www.seia.org/initiatives/whats-megawatt

#4 – Bioenergy

Bioenergy refers to energy derived from organic or biological sources, such as plants and animals. The two main categories of bioenergy are biofuels and biomass. Biofuels are liquid fuels like ethanol and biodiesel that are made from crops like corn, sugarcane, and soybeans. Biomass refers to organic material like wood, crops, and waste that can be burned directly for energy or converted into fuels like biogas.

Bioenergy is considered renewable because the feedstocks can be regrown relatively quickly. Some key feedstocks for bioenergy include:

Corn – Used for producing ethanol in the United States.
Sugarcane – A major source of bioethanol, especially in Brazil.

Soybeans – Processed into biodiesel.
Wood and agricultural waste – Burned for heat and power generation.
Organic municipal solid waste – Can be converted into biogas.

Some benefits of bioenergy include reducing dependence on fossil fuels, lowering greenhouse gas emissions compared to conventional fuels, supporting rural economies through additional crop markets, and improved waste management. However, there are also some concerns such as potential deforestation to grow energy crops, increased food prices if crops are diverted from food to fuel, and air/water pollution from improper waste biomass processing.

According to the International Energy Agency (https://www.iea.org/reports/renewables-2019/bioenergy), bioenergy contributed about 5% of total global primary energy supply in 2018. While growth has slowed in recent years, bioenergy remains an important renewable energy source, especially for heating and transport applications.

#5 – Geothermal

Geothermal energy comes from the heat within the earth. It is renewable and sustainable. There are three main uses of geothermal energy:

Using geothermal heat pumps to heat and cool buildings. This takes advantage of the stable temperatures underground.
Using geothermal reservoirs directly for heating purposes. This is done by piping hot water or steam from underground reservoirs directly to buildings or industrial processes.
Generating electricity from geothermal energy. This is done by using hot water or steam from geothermal reservoirs to power turbines and generators.

Some of the pros of geothermal energy are that it provides constant and reliable baseload power, has a small footprint, and emits little greenhouse gases. Some cons are that it depends on specific geologic sites, can have high upfront costs, and does carry some risks like induced seismicity.

Global geothermal power generation capacity exceeded 13.2GW in 2018 making it the fifth-biggest renewable source for electricity generation. Source

Global Growth Trends

Over the past decade, the renewable energy sector has seen exceptional growth around the world. According to the International Energy Agency (IEA) report, global renewable electricity capacity is projected to rise to 4,500 gigawatts (GW) in 2023, up from 2,501 GW in 2019. This represents an 80% increase over just 4 years. The share of renewables in global electricity generation has also risen significantly, from 20% in 2010 to over 42% in 2028 according to IEA projections.

Looking ahead, the growth and adoption of renewable energy sources is expected to accelerate further. The IEA forecasts that by 2030, renewables will account for over 60% of total global electricity generation as more countries commit to renewable energy targets. Key growth will come from solar and wind power, which are projected to supply over 25% of the world’s electricity by 2030. With rapidly falling technology costs and strong policy support, the renewable energy transition is picking up momentum globally.

Challenges

There are several key challenges associated with the growth and adoption of renewable energy sources. Some of the main obstacles include:

Storage limitations – Many renewable sources like solar and wind are intermittent, meaning they are not available on demand. Effective energy storage solutions are needed to capture and store energy for use when the sun isn’t shining or wind isn’t blowing. Developing grid-scale storage remains an obstacle.

Transmission capacity – Renewable energy projects are often located far from energy demand centers. Major investments in transmission infrastructure are required to deliver renewable electricity to consumers. Upgrading and building new transmission lines faces financial, regulatory and geographic hurdles.

Policy and regulatory factors – Renewable energy growth depends heavily on supportive policies like tax credits, feed-in tariffs, renewable portfolio standards and permitting. Changes in political leadership and priorities can hamper long-term growth. There is a need for consistent, long-term policy support.

High upfront capital costs – The upfront costs of building renewable energy projects from scratch are still higher than continuing to operate existing conventional power plants. Access to financing remains a key barrier, especially in developing nations.

Intermittency – The variability and unpredictability of renewable resources like wind and sunlight makes integrating high shares of renewables more complex. Sophisticated forecasting, system flexibility, and robust transmission networks help manage intermittency.

Sources: Identifying Factors of Success for Renewable Energy Growth Based on Consumer Perspectives, What is the challenges of utilizing renewable energy sources?

Benefits

Renewable energy provides numerous benefits for the environment, economy, and society. Some of the key benefits include:

Environmental benefits:

Renewable energy produces little to no global warming emissions (1). Using renewable energy leads to lower emissions of greenhouse gases like carbon dioxide, methane, and nitrous oxide, which contribute to climate change.
Renewable energy improves public health by reducing air pollution. Unlike fossil fuels, most types of renewable energy don’t emit harmful pollutants into the air (2).

Economic benefits:

Renewable energy creates jobs and spurs economic growth in manufacturing, installation, and other industries (3). According to the Department of Energy, renewable energy employs hundreds of thousands of Americans (3).
In many cases, the long-term costs of renewable energy are lower than conventional energy sources. Renewable energy doesn’t require fuel and involves little maintenance and operation costs.

Social benefits:

Renewable energy enhances energy security by relying on inexhaustible domestic energy sources. This reduces dependence on imported fossil fuels.
Renewable energy expands energy access. It can provide power to remote areas without electricity, both in developed and developing nations (3).

In summary, renewable energy delivers widespread benefits by reducing environmental impacts, stimulating economic growth, and improving energy equity.

Conclusion

In conclusion, the 5 most used renewable sources of energy are hydroelectric, wind, solar, bioenergy, and geothermal. Hydroelectric power generates electricity by utilizing the power of moving water; wind power harnesses the wind to spin large turbines that generate electricity; solar power converts energy from the sun into electricity through photovoltaic cells; bioenergy utilizes organic matter like plants, waste, and alcohol fuels to produce energy; and geothermal energy taps heat from underneath the earth’s surface to generate power.

Renewable energy sources are growing rapidly as countries around the world work to transition away from fossil fuels and toward sustainable energy. The future of renewable energy looks bright, with innovations in technology driving down costs and making clean power more accessible globally. While renewables face challenges around intermittency and storage, their environmental and economic benefits make them an essential component of plans to mitigate climate change and provide affordable electricity access worldwide.