Renewable energy is energy that comes from sources that naturally replenish themselves and will essentially never be depleted. Many non-renewable energy sources are still in use today. For instance, coal, fossil natural gas, and petroleum are materials that take thousands of years to replenish. In addition, when these sources are burned, they release greenhouse gases and air pollutants that are harmful to human and environmental health. Renewable energy comes from sources like solar and wind energy, hydroelectric power, geothermal energy, and biomass energy.
Solar power consists of collecting sunlight (a form of heat energy) and converting it into electricity. Solar power systems are beneficial because they do not produce carbon dioxide or air pollutants, and they have little effect on the environment. Solar energy is also limited because sunlight that reaches Earth’s surface is not always constant because of weather, seasons, and location. Solar power systems also need to have large surface areas to collect a useful amount of energy. In Vietnam, a new solar energy plant is in the process of being developed, but to avoid competing for space for other projects, it has been designed to float in waterways and reservoirs.
A floating solar power plant designed by the electonics company Kyocera being built in Japan. Source: https://www.fircroft.com/blogs/seven-of-the-biggest-renewable-energy-projects-in-the-world-92323134611
Wind power produces energy through turbines: wind rotates the turbine’s blades to turn on a generator that produces electricity. Like solar power, wind turbines do not release carbon dioxide or pollutants (with rare exceptions). Some negative effects of wind turbines are that they can cause bird and bat deaths, visually change landscapes, and produce irritating noise. One of the most impressive wind farms in the world is the Walney Wind Farm in the United Kingdom, which is home to 189 turbines. Like the floating solar power plant, the wind turbines at the Walney farm are located in the water to prevent taking up too much space.
Walney Wind Farm off the coast of the United Kingdom. Source: https://www.fircroft.com/blogs/seven-of-the-biggest-renewable-energy-projects-in-the-world-92323134611
Hydroelectric power uses moving water to rotate turbines that activate a generator that produces electricity. The more water there is and the faster it moves through the turbines the more energy is produced. Dams are often used for hydroelectric power, too. By creating a reservoir with the dams, the water can be released as needed to produce electricity. While hydroelectric dams do not directly emit air pollutants, they still have other effects on the environment. Dams and reservoirs can prevent natural fish migration patterns and species population, and water flow, temperature and chemistry. These changes can negatively affect the ecosystem around the river, such as plant and animal species. Constructing dams and reservoirs can also cause the relocation of communities. One example of a hydroelectric power plant is the Three Gorges Dam across the Yangtze River in China. It is one of the world’s largest power plants and is able to produce up to 22,500MW of electricity, which is enough energy to offset 31 million tons of coal consumption each year. While the am produces clear benefits, it also has environmental consequences, such as the fact that it has drastically changed the landscape of the river and nearby land, not to mention the increased risks in earthquakes and mudslides it may cause and the endangerment to the ecosystem.
Dams like the Three Gorges Dam have large negative and positive environmental impacts. Source: https://www.fircroft.com/blogs/seven-of-the-biggest-renewable-energy-projects-in-the-world-92323134611
Geothermal power harnesses the natural heat that comes from the Earth’s inner layers. At geothermal power plants, the heat can be used to generate steam that spins turbines to create electricity, while geothermal heat pumps can transfer heat from under Earth’s surface to warm houses. Geothermal energy emits very little air pollution and is a reliable source of energy. Currently, it is unclear if geothermal energy can be depleted by cooling down after time and they may be difficult to install if land is scarce.
An example of how a geothermal power plant could work. Source: https://archive.epa.gov/climatechange/kids/solutions/technologies/geothermal.html
Another source of renewable energy is biomass, which is organic material that stores energy from the sun. When biomass is burned, that energy is released as heat, which can create steam that helps generate electricity, or heat buildings. Examples of biomass materials are wood, cardboard, food waste, leather, and leaves. Biomass can also be converted into biogas and biofuel. Biogas is created when materials, like animal waste and landfill waste, decompose and produce methane gas. This gas can be collected and heated to produce steam that activates an electricity generator. Biofuel is often produced by decomposing plant materials, like corn and soy, and once available, the biofuel can be used to create electricity similar to how biogas is used. In general, biogas and biofuel are considered to be carbon-neutral because even though they release carbon-dioxide (a greenhouse gas) when they are burned, the plants and organic material used to make the biomass use carbon-dioxide to either grow or decompose.
An example of how biogas can be collected from landfills. Source:
According to the British Business Group Vietnam (BBGV), renewable energy accounts for only 2.1% of the total power generated in Vietnam. Of that percentage, hydropower provides nearly a quarter of that energy, followed by wind energy. Wind and solar power have great potential in Vietnam because its long coastline creates access to wind from the ocean, while Vietnam’s climate and location exposes it to a lot of sunlight. Biomass also has great potential because the country’s waste consists of mostly organic material, such as food and agricultural waste, firewood, and livestock waste. As Vietnam continues to develop its economy and technological capabilities, the country will soon have enough resources to harness renewable energy.
Scarlett Cheung - Foodbank VietNam