Renewable / Sustainable Energies
Renewable energy, collected from renewable resources such as sunlight, wind, water (tides, waves) or geothermal heat now provides more than 26.7% of global energy consumption in 20181 with 10.3% from modern renewable energy, while 16.4% from traditional biomass, predominantly for cooking and heating in the developing world. Adoption became rather on the slow uptrends, severely so in most of the under-developed countries. An estimated 17 countries generated more than 90% of their electricity with renewable sources in 2017. Most of them by hydropower and wind power like Costa Rica, Uruguay, and Ethiopia.
A source of energy made available from materials derived from biological sources. Biomass is any organic materials which has stored sunlight in the form of chemical energy, which in turn can be made into fuel. Biofuel include the likes of corn, soybeans, willow, switchgrass, rapeseed, wheat, sugar beet, sugarcane, sorghum, cassava, and jatropha, while biodegradable wastes like straw, timber, manure, rice husks, sewage, and food waste can also be used as biofuel.
Biomass can be converted to othre usable forms of energy like methane or ethanol and biodiesel. Crops can be used to produce ethanol or biodiesel (through fermentation and the likes), while things like human waste can be used to provide methane. However, some forms of forest bioenergy can be considered harmful as they release more carbon dioxide to the atmosphere than coal2 and can permanently damage any forested region, since it encourages the practice of whole-tree-harvesting.
A source of energy made available from sunlight converted to usable energy using semiconductor material (specifically N-type and P-type). When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. This process of converting light (photons) to electricity (voltage) is called the photovoltaic effect. Currently solar panels convert most of the visible light spectrum and about half of the ultraviolet and infrared light spectrum to usable solar energy. Normal photovoltaic solar cell efficiency in the consumer grade products in 2018 varies from 15-22%, while theoretically the ultimate efficiency of single p-n junction should be capable of reaching 33.16%. There are many applications for solar energy including providing electricity, water heating, heating and lighting buildings, or as a transpired collector for preconditioning environment temperature in industrial space.
China leads the way alongside India in Asia with more than 75% solar power adoption in 2017 alone, with more solar PV installed globally than the net additions of fossil fuels and nuclear power combined. Global capacity increased nearly one-third to approximately 402GWdc. As of 2017, each continent produces more than 1GW of solar power capacity, with some countries alone measures far beyond that of 1GW, notably China, US, Japan, Germany, and Italy. With Germany leads the solar PV per capita as of 2017. For industrial space, concentrating solar thermal power leader is Spain, followed by US, South Africa, India and Morocco.
A wind turbine - can use the wind’s energy to generate electricity. Wind turbines, like windmills, are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and less turbulent wind. Turbines catch the wind’s energy with their propeller-like blades. Usually, two or three blades are mounted on a shaft to form a rotor.
A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the wind’s force against the front side of the blade, which is called drag. The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.
Geothermal energy is the heat / thermal energy generated or stored from the Earth. It’s clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth’s surface, and down even deeper to the extremely high temperatures of molten rock called magma. Geothermal power is also considered to be both renewable and sustainable, furthermore due to its low emissions geothermal energy is considered to have excellent potential for mitigation of global warming. For instance, existing geothermal electric plants emit an average of 122 kilograms of CO2 per MWh or just a fraction of emission intensity of conventional fossil fuel plants.
Global capacity of Geothermal energy measures around 12 GW, with the US, Philippines, and Indonesia as the top three. However, Indonesia is poised to be the global leader of geothermal adoption in the next decade and Turkey is one of the fastest growing geothermal plant producer in the world with 34% increase in 2017 alone.
Hydropower and Ocean Energy
Hydroelectric power is power generated from hydropower, the energy of falling water or fast running water like waterfalls, or river currents. In 2015, hydropower generated over 16.6% of the world’s total electricity and 70% of all renewable electricity, and was expected to increase around 3.1% each year. It is relatively low in cost, and high value clean electricity. It is also highly cost-effective in its economic lives, hydroelectric dams and plants are still in service 50-100 years after its build. Hydroelectric dams do not use fuel, so it does not produce carbon dioxide, thus has the lowest lifecycle greenhouse gas emissions for power generation.
Ocean energy is the energy carried by ocean waves, tides, salinity and ocean temperature difference. The movement of water in the world’s oceans creates a vast store of kinetic energy, or energy in motion. This enenrgy can be harnessed to generate electricity to power homes, transport, and industries. This remained one of the most underutilized form of renewable and sustainable energy, with only 529 MW of operating ocean energy out of the potential 20-80,000 TWh per year from changes in ocean temperature, salt content, movement of tides, currents, waves and swells. Out of the countries in the world, archipelagic countries such as Indonesia has the most potential ocean energy (around 49 GW) and has 727 GW theoretical potential ocean energy3.
By: Vincent Didiek Wiet Aryanto
- https://www.ren21.net/wp-content/uploads/2018/06/17-8652_GSR2018_FullReport_web_-1.pdf [return]
- https://greenpeace.org//canada/en/campaigns/forests/boreal/archive/Burning-trees-for-energy-puts-Canadian-forests-and-climate-at-risk-Greenpeace/ [return]
- https://en.wikipedia.org/wiki/Marine_energy [return]