What is renewable energy? Common types and benefits

What is renewable energy?

Renewable energy, also known as green energy, is a type of energy derived from natural sources that can be replenished quickly compared to the rate of human consumption. This means renewable energy sources won’t deplete, unlike fossil fuels.

Renewable energy is divided into 2 main sources:

Intermittent renewable energy

These are energy sources that depend on natural conditions, such as wind speed or sunlight. They can’t provide a stable and continuous supply of energy.

Examples: wind energy, solar energy

Controllable renewable energy

These energy sources can be adjusted and controlled according to usage demands. They provide greater stability in electricity supply.

Examples: hydropower, bioenergy, and geothermal energy

In contrast, traditional energy sources, such as coal, oil, and natural gas, are not renewable. These sources need millions of years to form underground and will be depleted due to rapid extraction.

Thus, renewable energy will become a critical alternative. This is true when fossil resources become scarce and climate change becomes more urgent.

Why is renewable energy important?

The transition to renewable energy is not only crucial in protecting the environment. It’s the key factor in achieving the Net-zero goal.

The energy sector is the largest source of emissions

According to the IEA, the energy sector is the largest source of GHG emissions. It accounts for about three-quarters of global emissions.

Currently, the number of countries committed to achieving Net Zero has rapidly increased. They cover about 70% of global CO2 emissions.

Yet, even if these commitments work out as planned, CO2 emissions still reach around 22 billion tons by 2050. This could lead to a global temperature rise of 2.1°C by 2100. This drastic rise will cause severe environmental and human health consequences.

So, to achieve the Net-zero goal, the immediate and large-scale deployment of existing clean and efficient energy technologies is essential. In this context, the transition to renewable energy will play a central role.

Renewable energy is the key to reducing emissions

As the energy sector becomes cleaner through renewable energy, electrification will be the next step. The IEA predicts that electric vehicles will account for more than 60% of global car sales by 2030, up from the current 5%.

The shift to renewable energy-powered vehicles is more impactful than you might think. The IEA estimates that about 55% of global emission reductions are related to consumer behavior. This includes switching to electric vehicles.

These figures speak for themselves. Transitioning to renewable energy is crucial in the fight against climate change and achieving Net Zero.

Common renewable energy types

Below are the most common renewable energy types:

Fluctuations in global renewable energy output as of 2020. Source: Energy Institute Statistical Review of World Energy.

Hydropower (14.3% of global electricity production)

Hydropower is a renewable energy source generated by harnessing the energy from flowing water. When water from rivers or reservoirs is directed through turbines, it spins the blades. This movement produces electricity.

Water has a density about 800 times greater than air. This allows for energy conversion efficiency of up to 90%.

This is the highest conversion rate among renewable energy types.

Hydropower is widely used to supply electricity to large regions and is often the primary energy source for many countries. Also, the reservoirs of hydroelectric dams can also manage floods and provide irrigation water.

Hydroelectricity generates energy from the flow of water.

Solar energy (5.5% of global electricity production)

Solar energy is a renewable energy source harnessed from the sun's radiation. There are 2 main types:

• Solar thermal energy
• Photovoltaic energy

Solar thermal energy converts sunlight into heat for water or air heating.

Meanwhile, photovoltaic energy directly converts sunlight into electricity through solar panels. Photovoltaics account for about two-thirds of global solar power capacity. Its efficiency typically ranges from 15-23%.

Solar energy is widely applied, from household to corporate scales. It doesn’t cause GHG emissions during operation.

Solar energy generates electricity by converting sunlight into electricity through solar panels.

Wind energy (7.8% of global electricity production)

Wind energy is a renewable energy source created by harnessing wind to spin wind turbines. This movement generates electricity. Wind energy is divided into 2 types:

• Onshore wind energy
• Offshore wind energy

Onshore wind turbines are installed on land. They have lower installation and maintenance costs. Yet, they also have lower efficiency due to inconsistent wind speeds. In contrast, offshore wind turbines are exposed to higher wind speeds. This offers greater efficiency but with higher construction and maintenance costs.

Wind energy is one of the fastest-growing energy sources. This is especially true in regions with favorable wind conditions.

Wind power generates electricity by rotating wind turbines, which in turn generates electricity.

Wind energy production by region as of 2022. Source: Energy Institute Statistical Review of World Energy.

Bioenergy (2.4% of global electricity production)

Bioenergy is a renewable energy source produced from biological materials. They're mainly derived from living organisms like plants.

Bioenergy can be generated by burning biomass to create heat. It can also be converted into biofuels such as ethanol and biodiesel. Wood and sawdust are common sources of bioenergy. They're often used for heating or combustion to generate electricity.

Bioenergy is a sustainable energy source. This is particularly true in rural areas with abundant agricultural resources.

Bioenergy can be produced directly through combustion to generate heat or converted into biofuels.

Geothermal energy (<1% of global electricity production)

Geothermal energy is a renewable energy source that comes from the heat within the Earth. This heat results from the radioactive decay of elements in the Earth's interior.

Geothermal energy is typically harnessed through deep wells for direct heating. Geothermal power plants have high efficiency. This is especially true in areas with a strong geothermal activity. These areas are often located at tectonic plate boundaries where the Earth's mantle is more exposed.

Geothermal energy contributes only a small part of global electricity production. Yet, it's a highly stable energy source. This is because it doesn't depend on weather conditions. Thus, geothermal energy can provide a continuous power supply in some regions.

A geothermal plant collects heat from within the Earth's crust through a system of pipes.

Benefits of renewable energy

Renewable energy has the potential to transform the global economy in a positive way. Below are some benefits of renewable energy:

Reducing dependence on mineral resources

To power a 100W light bulb for one year, it takes 325 kg of coal. A coal-powered generator can only convert 40% of thermal energy into electricity.

By using renewable energy, countries can reduce their reliance on importing fossil fuels from abroad. This helps ensure energy security and mitigates risks associated with fuel price fluctuations.

This doesn't only stabilize energy supplies. It also minimizes the environmental impact caused by resource extraction.

Reducing pollution, improving human health

Unlike fossil fuels, producing renewable energy doesn't emit pollutants like SO2 and NO2. These are the primary causes of many respiratory and cardiovascular diseases.

Research shows that reducing pollution through renewable energy could prevent millions of deaths related to air pollution. Lowering pollution also reduces healthcare costs and improves quality of life. 

This is particularly true in densely populated urban areas and industrialized regions.

Reducing costs, easy access, construction, installation

According to a report, solar energy costs have dropped 90% over the past decade. Wind energy costs have decreased by 70%, and battery costs have fallen by more than 90%.

This is a result of increased technological output over time. In the future, the cost of building a solar power plant or a large-scale wind farm could be even lower. Imagine a fraction of the cost of a coal power plant.

Installing renewable energy systems, like rooftop solar panels, is also easy and quick. This provides immediate economic and environmental benefits.

The cost of solar energy production has significantly decreased over the decades. Source: Our World in Data.

Creating jobs in the renewable energy sector

According to the IEA, to meet the Net-zero goal, clean energy investments need to triple to around $4 trillion per year by 2030.

This will create 14 million jobs in renewable energy system manufacturing, installation, and maintenance. Thus, renewable energy can boost the global economy.

Yet, this transition will also displace 5 million jobs in the traditional energy and fossil fuel sectors. Governments and businesses will need to retrain the affected workforce.

Global employment projections in the energy sector by 2030. Source: IEA.

Improving the efficiency of the national grid

Incorporating renewable energy into the grid can reduce dependence on traditional power sources. This helps to reduce strain and increase the stability of the system.

According to a report, renewable energy will account for over 42% of global electricity production by 2028. This means renewable energy will relieve nearly half of the output pressure from traditional power plants.

Modern technologies like smart grids will also help optimize electricity distribution. They can also reduce losses during electric power transmission.

Challenges from renewable energy

Renewable energy also brings several challenges for governments, businesses, and even the environment. Some of these include:

Unstable output, dependent on weather

Renewable energy sources such as hydropower, solar, and wind energy can have unstable output. This is because they depend on weather conditions.

Hydropower can be affected by climate change and variations in water levels in reservoirs. This leads to fluctuations in electricity production. Solar power relies on sunlight, meaning output decreases on cloudy days or at night.

Likewise, wind energy depends on wind speed. Regions without consistent wind may struggle to maintain continuous electricity production.

Can generate greenhouse gas emissions

Some renewable energy sources, like bioenergy, can still produce GHG emissions. Burning biomass can generate CO2. Of course, these emissions are much lower than those from burning fossil fuels.

Producing batteries to store electricity can also lead to emissions. This happens during the extraction and processing of metals like lithium, nickel, and cobalt.

Yet, compared to traditional energy sources, renewable energy is still preferable. It offers greater advantages in reducing GHG emissions.

Requires resources for construction and installation

Transitioning to renewable energy requires extensive resource extraction to build and install infrastructure.

For example, wind energy requires large amounts of copper and zinc to make wind turbines. Solar energy demands aluminum for solar panel frames. Expanding the grid and installing storage batteries need a lot of copper, aluminum, and other metals.

The demand for metals for the production of batteries like lithium is expected to increase manyfold. This puts enormous pressure on these resources.

Takes up a lot of space for construction and installation

Renewable energy facilities need much larger land areas than fossil fuel power plants.

A solar farm can take up 10 times more land than a coal power plant to produce the same amount of electricity. Building wind farms and hydropower plants also demands extensive space.

The large land usage may lead to conflicts with agricultural purposes and nature conservation. As a result, the ecological balance can go off the line.

Renewable energy plants, such as solar power plants, often require large areas of land.

Causes noise pollution, flooding and displacement

Wind turbines emit noise at around 45 dB from a distance of 300 meters. While not too loud, prolonged exposure to this noise can be disruptive to nearby communities.

Meanwhile, the construction and operation of hydropower dams can cause flooding over large areas. This affects natural habitats and may lead to the displacement of residents.

Renewable energy projects are often developed in environmentally important areas. Thus, investors need to carefully consider minimizing negative impacts to protect affected ecosystems and communities.

Which renewable energy type is the best?

Renewable energy is the key to the environment problem. Yet, it isn't a perfect solution. They still cause emissions, directly or indirectly, during construction and operation.

Nonetheless, among renewable energy sources, wind and solar energy are the most optimal. This is due to their minimal impact on the environment. It's no coincidence the IEA has set a target for 90% of global electricity production to come from renewable energy by 2050. Of this, wind and solar power should account for 70%.

Although this requires significant initial investment, it promises long-term benefits. As of now, global output from wind and solar energy only accounts for about 13.3%. This underscores the urgent need for increased technology transfer and investment.

The current trends of renewable energy

Renewable energy is growing rapidly across the globe. There are significant disparities in production shares between countries.

Worldwide

At the 2023 United Nations Climate Change Conference (COP28), about three-quarters of countries worldwide set a target to triple their renewable energy capacity by 2030. The European Union (EU) also aims for a 40% share by the same year.

A map showing the share of electricity production from renewable energy in 2023. Source: Energy Institute Statistical Review of World Energy.

The map above shows that many countries have renewable energy contributing more than 50% of their total supply. These countries are located in East Asia, Australia, Europe, Central Africa, North America, and South America. Some even produce all their electricity from renewable sources.

The main factors behind this are:

Availability of resources: Europe and South America have abundant rivers suitable for hydropower. North America and Australia have favorable conditions for solar and wind energy.
National economies: These countries and regions have strong economies. This enables them to invest in renewable energy technology and infrastructure.
Advanced technology: These nations lead in renewable energy technologies. This allows for efficient exploitation of these energy sources.

In contrast, countries with low renewable energy shares are developing nations or those heavily reliant on available fossil fuel resources.

In Vietnam

Vietnam has made a leap forward in developing and transitioning to renewable energy. Hydropower, one of the primary renewable sources, has been almost fully exploited. This accounts for nearly 40% of the national electricity capacity. With more than 1,000 potential sites for hydropower, Vietnam continues to expand this energy source.

Solar energy is also gaining attention. With high sunlight hours (2,600 hours/year) and suitable radiation intensity (5.9 kWh/m²), Vietnam has a lot of potential. By mid-2019, solar power contributed over 8% of the country’s total electricity capacity.

A map showing solar energy potential in Vietnam. Source: Global Solar Atlas.

Wind energy is also gradually developing. Although by the end of 2018, the total wind power capacity was only 228 MW, this number increased to 611 MW by 2021. Many new projects are under construction. With a coastline over 3,000 km long and mountainous terrain, Vietnam has ideal conditions for wind energy.

A map showing wind speed potential in Vietnam. Source: Global Wind Atlas.

Biomass energy is also being explored, benefiting from Vietnam’s agricultural sector. Yet, electricity production from biomass remains slow due to efficiency issues and biomass waste. Also, Vietnam has potential in geothermal energy. There are over 250 hot spring sites, 43 of which are suitable for electricity generation.

How Oxalis applies renewable energy in tourism

Oxalis has incorporated renewable energy into various tourism activities to reduce environmental impact.

We use solar panels to power our offices, accommodations (Chay Lap Farmstay, Blue Diamond Camp, Tu Lan Lodge), campsites, and transportation. These panels provide clean electricity for lighting (headlamps during tours), cooling (mini fans used in camping tents), and charging devices (backup charger). Notably, Blue Diamond Camp has been fully powered by solar energy since June 2023.

Solar panels installed on the roofs of campsites at Blue Diamond Camp.

Oxalis future goals for renewable energy align with our Net Zero target. By 2026, Oxalis aims to cut Scope 2 emissions by fully transitioning to renewable electricity.

Also, Oxalis is implementing biogas systems at Tu Lan Lodge and Blue Diamond Camp. Biogas is extracted from biomass waste, collected from tours and accommodations. Once fully operational, biogas will provide clean energy for cooking at the Tu Lan Lodge restaurant and for camping activities at Blue Diamond Camp.

Join Oxalis in leading the transition to renewable energy. We're working non-stop toward the ultimate goal of Net Zero. Each step you take today contributes to a sustainable future for generations to come.

The Oxalis Experience.