Have you ever had a presentation where your teacher talks about the dangers of fossil fuel and the importance of being environmentally sustainable? You probably heard them mention vague terms such as “Hydroelectric Energy” or “Tidal”, confused as to exactly what they meant.
Where does our energy come from?
Around 80% of our energy comes from fossil fuels. The process to convert fossil fuels into the energy and electricity that we use today emits a lot of greenhouses gases which contribute to climate change. And by a lot, we mean almost 10 giga-tonnes of CO2 emissions per year!
Renewable energy is a form of energy which is considered to be unlimited with nearly no pollution. Imagine that. Now, almost all of us use coal, oil, and gas. At the astounding rate, we are burning these natural resources, it is said that oil will run out by 2052, gas by 2060, and coal by 2088. This is astounding since these are the primary sources of energy we use in the 21st century!
Check out this amazing website and see how much CO2 is emitted to produce electricity in REAL-TIME! It also shows how much renewable/low-carbon energy sources are being used. See how little Singapore relies on renewable energy – https://www.electricitymap.org
What is Solar energy?
Solar energy is when energy from the sun is turned into chemical energy that we use. There are two types of solar energy, solar thermal and solar PV. Our school (UWCSEA East), uses solar thermal currently, and we are trying to add solar PV’s too. Solar thermal is a type of solar energy for harnessing solar energy to generate thermal energy. This energy is used to heat water, food, etc. Solar PV is the solar energy that converts solar panels, which is more expensive. However, this energy can be used, not only to power thermal, but also electricity such as lights, fans, charging our phones and everything we use every day. What a difference that is!
A student-led organization ‘Solar for East’ tries to make the UWCSEA East campus a more sustainable place through the use of solar energy. Solar donation of $100 to supports 1/6th of a panel and a gift of $600 will fund a full panel. For more information, go to: https://www.uwcsea.edu.sg/node/27087.
What is Wind Energy?
Wind energy creates energy through wind turbines. It converts kinetic energy from the wind to mechanical power. It is a safe and clean energy source since it does not emit greenhouse gases and radioactive emissions. There are two types of Wind Energy which are offshore and onshore turbines. Offshore turbines can save space on land and usually there is stronger wind offshore. However, an offshore wind farm is very expensive and they are 90% more expensive than fossil fuel generators, and 50% more than nuclear. Onshore wind turbines are relatively cheap, once it is built but it can cause aesthetic impacts and the noise affect the people living by.
What is Hydroelectric Power?
It can take place in naturally occurring falling water or artificially created dams. The falling water turns the turbine which converts kinetic energy into mechanical energy. Then the generator converts the mechanical energy into electricity. Micro-hydropower produces around 5 kW to 100 kW of electricity using the natural flow of water and they are typically set up in areas capable of producing up to 100 kilowatts of electricity. Mega Dams are artificial dams that are made to contain a large amount of water to produce a huge amount of energy.
The Three Gorges Dam in China is the world’s largest power station in terms of installed capacity. It has a total generation capacity of 22,500 MW and accounts for 3% of China’s energy needs. TheThree Gorges Dam also control and make river navigation easier which has improved trade. However, the dam has caused social, environmental and economic impacts. For example, over 1 million people were displaced and increased the risk of landslides due to the changing water levels. 632km2 of land submerged and 8000 historical sites and fertile land disappeared underwater. The dam also affected biodiversity such as the extinction of the beautiful Yangtze river dolphins which was nicknamed, “Goddess of the Yangtze”. Check out this website for more information about the Three Gorges Dam: https://www.internationalrivers.org/campaigns/three-gorges-dam
We think that micro-hydropower is better than the mega-dams because no reservoir is required which means that there is a relatively little impact on the surrounding ecology. It is a cost-effective energy source so it is a potential technology for the developing countries to supply electricity in a sustainable way.
What is Tidal energy?
The gravitational forces applied by the moon, sun and rotation of earth cause the tide to rise and fall which cause the turbines to spin underwater. Tidal energy is a clean energy source and it can produce a large amount of energy comparing to other renewable energy sources. However, there are harsh conditions for Tidal plants, for example, to produce electricity, the difference in water levels, also known as the tidal range, must be at least 5 meters. Tidal energy cost more than $400 per MWH but it is relatively cheap after it is built. In addition, the power plants are often located far from communities consuming the energy from its limited locations so it costs extra money for electricity to reach communities. It can be harmful to marine life as power plants can disrupt movements and migration of animals and can be killed by turbines. Tidal energy is an intermittent energy source as tides occur only twice a day.
What is Biomass?
Biomass is an industry term for burning wood and other organic matter to gain energy. Biomass releases carbon emissions but some say that it is carbon-neutral because the replaced plants will take in carbon dioxide. This energy source is considered as a renewable energy source because we can replace plants. It is relatively cheap for a renewable energy source so it is a great source of energy to reduce world’s dependence on fossil fuels, especially LEDC countries. However, biomass takes a lot of space and it was previously used for growing food which means that food price increases due to the decrease in food supply. Biomass may have replaced part of a forest which means deforestation was caused.
You can learn more here:
- https://de.wikipedia.org/wiki/Datei:World_energy_consumption_by_fuel.svg (Pie chart of the world energy consumption by source)
- https://www.eia.gov/energyexplained/?page=renewable_home
