Fact I : Increase in renewable use
Since the 1965, there has been a large increase in the share of renewable energies.
Fact II.
China leads the world as the top producer of solar energy with an installed capacity of 253.6 GW. The EU, United States, Vietnam, and Japan are also considered among the top producer of solar energy.
Fact III.
Fossil fuel energy consumption as per 2020 was 140,000 TWh
Solar energy
Solar energy is the most abundant of all available energy sources on Earth. The sun has produced energy for billions of years and is the ultimate source for all of the energy sources and fuels that we use today. Over time, people developed technologies to collect solar energy for heat and to convert it into electricity. The rate at which solar energy is intercepted by the Earth is about 10,000 times greater than the rate at which humankind consumes energy[2]. Infact, the amount of sunlight that strikes the earth's surface in an hour and a half is enough to handle the entire world's energy consumption for a full year[3].
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Primarily, there are three main ways to harness solar energy:
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Photovoltaics (PV): This is the most common technology you’re likely to be more familiar with, which is utilized in the solar panels. When photons (aka the light energy particles) hit the solar panels, the energy from the sunlight is absorbed by the PV cells. This energy creates electrical charges that move in response to an internal electrical field in the cell, causing electricity to flow. Rapidly falling prices have made solar more affordable than ever. The average price of a completed PV system has dropped by 59 percent over the last decade.
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Solar heating & cooling: This is another major way of harnessing the solar energy by using the heat from it. Solar heating & cooling (SHC) technologies collect the thermal energy from the sun and use this heat to provide hot water, space heating, cooling, and pool heating for residential, commercial, and industrial applications. Solar water heating systems are comprised of three main elements: the solar collector, insulated piping, and a hot water storage tank. The solar collector gathers the heat from solar radiation and transfers the heat to potable water. This heated water flows out of the collector to a hot water tank, and is used as necessary.
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Concentrating solar power: This technology is more feasible at an industry level. It used mirrors to concentrate the solar energy to drive traditional steam turbines or engines that create electricity. The thermal energy concentrated in a CSP plant can be stored and used to produce electricity when it is needed, day or night.
Wind
Wind energy is produced for consumption by harnessing the kinetic energy of moving air with the help of turbines located on onshore or in the ocean/sea/freshwater (offshore). Though the average wind speeds and hence the availability of wind energy depends on the location, the world’s technical potential for wind energy exceeds global electricity production, and ample potential exists in most regions of the world to enable significant wind energy deployment.
Wind energy is correlated to the sun. The sun’s uneven heating of the atmosphere, the Earth’s irregular surfaces, and the Earth’s rotation: all are responsible for producing wind globally. The amount of power that can be harvested from wind depends on the size of the turbine and the length of its blades. The output is proportional to the dimensions of the rotor and to the cube of the wind speed. Theoretically, when wind speed doubles, wind power potential increases by a factor of eight.
According to the Global Wind Energy Council (GWEC) in its Global Wind Report 2021, the entire global wind power fleet, both onshore and offshore, totalled 743 gigawatts (GW) at the end of 2020. That is enough to avoid more than 1.1 billion tonnes of CO2 globally – roughly equivalent to the annual carbon emissions of Japan, the world’s fifth-highest emitting country.
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China leads the wind energy capacity too, totalling just over 288 GW at the end of 2020. The United States, Germany, India and Spain are also among the leading wind power generator.
Coal
Being the least expsenvie of fossil fuels and its abundance make it a very lucrative and widely used energy source. Hence, this translates into it being the most popular source of energy, accounting for almost 40 per cent of the total worldwide power generation.
The formation of coal takes place from prehistoric vegetation that accumulated about 300 million years ago. It was a time when much of the Earth's surface was covered in swamps. When the remains of the dead plant and trees started sinking into the swamp land, it resulted in the formation of a dense material called peat. Over time, layers of sediment and soil accumulated over the peat. The combination of heat from the Earth's core and pressure of the rock and sediments caused the eventual formation of carbon-rich coal.There are four types of coal categorized according to the amount of heat and pressure under the Earth’s strata, carbon and sulphur content and moisture level: lignite, sub-bituminous, bituminous, and anthracite.
Several principal emissions result from coal combustion [2]:
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Sulfur dioxide (SO2), which contributes to acid rain and respiratory illnesses
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Nitrogen oxides (NOx), which contribute to smog and respiratory illnesses
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Particulates, which contribute to smog, haze, and respiratory illnesses and lung disease
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Carbon dioxide (CO2), which is the primary greenhouse gas produced from burning fossil fuels (coal, oil, and natural gas)
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Mercury and other heavy metals, which have been linked to both neurological and developmental damage in humans and other animals
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Fly ash and bottom ash, which are residues created when power plants burn coal
Geothermal
Geothermal energy is still in its infancy as compared to other sources of renewable energy. It works on the principle of using the heat derived within the sub-surface of the Earth. Water or steam is responsible for carrying this trapped heat to the Earth’s surface, where it can then be utilized for different purposes. Depending on its characteristics, geothermal energy can be used for heating and cooling purposes or be harnessed to generate clean electricity. However, for electricity generation, high or medium temperature resources are needed, which are usually located close to tectonically active regions.
What makes geothermal energy one of the most attractive and reliable renewable energies is the fact that unlike solar and wind energy sources, the geothermal energy source is not intermittent by nature and thus, offers reliable, consistent, and sustainable energy solutions.
Global geothermal power generation capacity stood at 15,854 MW at the year-end 2021[5]. The United States leads this category producing over 3722 MW, followed by Indonesia, Philippines, Turkey and New Zealand.