Importance of renewable resources – Solar, Wind, small/Mini/Micro hydel, Biomass, waste based, geothermal, tidal & fuel cells

Importance of renewable energy resources

Renewable energy are sources of clean, inexhaustible and increasingly competitive energy. They differ from fossil fuels principally in their diversity, abundance and potential for use anywhere on the planet, but above all in that they produce neither greenhouse gases – which cause climate change – nor polluting emissions. Their costs are also falling and at a sustainable rate, whereas the general cost trend for fossil fuels is in the opposite direction in spite of their present volatility.

Solar energy resources

Solar is a safe alternative which can replace current fossil fuels like coal and gas for generation of electricity that produce air, water, and land pollution. electricity generation from fossil fuels causes pollution of air leading to acid rain, damaged forest areas, and affected agricultural production leading to loss of billions of dollars worldwide. Fracking in the U.S. uses thousands of liters of water mixed with chemicals for extraction contaminating the water used, along with nearby water bodies, and also causes earthquakes. Nuclear power pollutes water and land and has caused environmental catastrophes. Use of solar energy will eliminate these unsafe, unclean consequences from using conventional fossil fuels.

Pristine forests are destroyed for mining raw materials like fossil or nuclear fuels. Trees constantly remove and use carbon dioxide from the air to make their food, and this carbon is then stored in them. When forests are cut for mining raw materials for conventional energy, this major carbon sink disappears and also increases climate change. “Nine out of ten animals on land” live in forests, according to WWF, and a loss of habitats diminishes their populations. Switching to solar power is important to keep these habitats intact for the animals who live there as well as continue to keep the air clean.

The electric power sector accounted for most greenhouse gas emissions in the world. The emissions lead to a rise in global temperatures, and changes in weather patterns leading to a cascade of effects. Heat waves, and increase in disease-spreading insects cause health problems especially for children and the elderly.  Climate change has lead to increase in flooding and hurricanes due to disturbed weather patterns. Higher carbon dioxide concentration is making oceans acidic and killing marine life, like corals. Climate change causes extinct of species from Sub-Arctic Boreal forests to tropical Amazon forests. Higher temperatures result melting of polar ice caps, reducing habitats for wildlife and also increase sea level. This results in submersion and loss of land along the coast, displacing people. Irregular rainfall or increasing droughts affects agriculture and livelihoods of the weaker sections of society globally.

Wind energy

Wind energy is produced by the movement of air (wind) and converted into power for human use. Wind has been used as a source of energy for more than a thousand years, but was replaced by fossil fuels for much of the 20th century. Today, wind is making a comeback as a source of electricity and power.

Wind energy is produced with wind turbines—tall, tubular towers with blades rotating at the top. When the wind turns the blades, the blades turn a generator and create electricity. Wind turbines can have a horizontal or vertical axis. The turbines do not actually produce wind energy. The blades turn, convert the energy of wind into rotational energy, a form of mechanical energy, and this energy is in turn converted into electrical energy.

There are many advantages to using the wind’s energy to create electricity:

  • Wind cannot be used up—it occurs naturally, whether we harness it for electricity or not.
  • Wind is a clean source of fuel. Turbines have no emissions and do not pollute the air. This is globally important as more countries industrialize and increase their demand for electricity for homes, businesses, hospitals, and schools. Many schools in the U.S. state of Iowa, for example, have installed wind turbines. Initial investments in the machinery and equipment have been offset by savings of more than $100,000 a year. The schools also emit millions fewer kilograms of carbon dioxide.
  • Wind energy is cheap! It is one of the lowest-priced renewable energy sources. In the U.S., it costs between 4 and 6 cents per kilowatt-hour. That is cheaper than natural gas, although still more expensive than nuclear energy or coal.
  • Wind is generated all over the planet, and wind turbines can be installed economically almost everywhere. This makes it a key resource in developing economies. Nuclear energy, for instance, demands a workforce with substantial educational and engineering backgrounds, as well as an initial investment for nuclear power plants. Development of fossil fuel power plants relies on even more factors: the presence of coal, oil, or gas; the equipment and technology to refine it; and the finances to import or export the raw or refined goods. Nepal, for example, is a developing country with no fossil fuel resources, but it is rich in windy Himalayan mountain passes. Nepalese leaders are developing a policy to invest in wind farm projects using local materials. This would expand the nation’s power grid and allow for greater industrial development.

Importance of small/Mini/Micro hydel projects

  • The construction of large dams and associated civil structures can for example result in an alteration of water quantity in downstream areas, affecting long-practiced farming practices such as flood-dependant recession agriculture. Water quality and biodiversity can be decreased by increased erosion and thus sedimentation due to deforestation due to construction work and resettlement.
  • Large hydropower plants’ reservoirs produce a significant amount of greenhouse gases such as carbon dioxides and methane, in some cases emissions are found to be higher than from plants running from fossil fuels. This is because, due to the initial flooding of the reservoir, a large amount of carbon tied in vegetation is released when the plants rot. Methane, on the other hand, builds up due to the anoxic decomposition of organic matter on the reservoirs’ bottom.
  • Resettlement programs associated with the construction of large dams also have a variety of socio-economic impacts. People are often relocated to less suitable areas (steep terrain or less fertile soils) which does not only increase land degradation but also puts them at high impoverishment risk.
  • It only takes a small amount of flow (as little as few litres per minute) or a drop as low as 1 m to generate electricity with micro hydro. Electricity can be delivered as far as 1 km away to the location where it is being used. If planned carefully and well adapted to the environmental conditions, micro hydropower schemes produce a continuous and predictable supply of electrical energy in comparison to other small-scale renewable technologies.

Importance of biomass as energy

Biomass energy has rapidly become a vital part of the global renewable energy mix and account for an ever-growing share of electric capacity added worldwide.

Traditional biomass, primarily for cooking and heating, represents about 13 percent and is growing slowly or even declining in some regions as biomass is used more efficiently or replaced by more modern energy forms. Some of the recent predictions suggest that biomass energy is likely to make up one third of the total world energy mix by 2050. Infact, biofuel provides around 3% of the world’s fuel for transport.

Biomass energy resources are readily available in rural and urban areas of all countries. Biomass-based industries can foster rural development, provide employment opportunities and promote biomass re-growth through sustainable land management practices.

Bioenergy systems offer significant possibilities for reducing greenhouse gas emissions due to their immense potential to replace fossil fuels in energy production. Biomass reduces emissions and enhances carbon sequestration since short-rotation crops or forests established on abandoned agricultural land accumulate carbon in the soil.

Bioenergy usually provides an irreversible mitigation effect by reducing carbon dioxide at source, but it may emit more carbon per unit of energy than fossil fuels unless biomass fuels are produced unsustainably.

Biomass can play a major role in reducing the reliance on fossil fuels by making use of thermochemical conversion technologies. In addition, the increased utilization of biomass-based fuels will be instrumental in safeguarding the environment, generation of new job opportunities, sustainable development and health improvements in rural areas.

The development of efficient biomass handling technology, improvement of agro-forestry systems and establishment of small and large-scale biomass-based power plants can play a major role in rural development. Biomass energy could also aid in modernizing the agricultural economy.

 

Waste based energy

Each month millions of tons of waste is produced. Either they become a part of landfill or are exported to third world countries.  This causes huge environmental impact in terms of wildlife, ecosystems and to human health. Keeping this in mind, many new waste treatment plants have come up and have developed new ways to generate energy from landfill waste.

Waste-to-energy has been evolving over the years and there are many new developments in this technology, moving in mainly one direction – to be able to applied to smaller size waste streams. Not only is it a strategy that has real importance for the current public policy, it is a strategy that will definitely present itself to additional areas.

More than 50% of waste that is burnt in waste-to-energy facilities is already part of the short carbon cycle. In which case, it has an organic derivative and it doesn’t add to climate change, to begin with. The long form carbon that is burned, things like plastics that have come out of the ground in the form of oil do add to climate change. But, they have already been used once. They have already been extracted once and what we are doing is taking the energy out of them after that physical use, capturing some of that (energy), thereby offsetting more carbon from natural gas or oil or coal. So, the net effect is a reduction in carbon emissions.

Waste-to-energy and recycling are complementary depending on the results of analyses of the First and Second Laws of Thermodynamics, which are absolutely valid. One can decide in specific situations whether waste-to-energy or whether some type of recycling technology would be more appropriate. It is not an either/or option.

Importance of geothermal energy

Geo’ means earth and ‘thermal’ means heat. Thus geothermal energy is that heat energy obtained from hot rocks present inside the earth, and this can  be used as a source of energy to produce electricity. From the surface down through the crust, the normal temperature gradient( the increase of temperature with the increase of depth ) in the Earth’s crust is 17 °C — 30 °C per kilometre of depth (50 °F — 87 °F per mile).

Geothermal energy is an enormous, underused heat and power resource that is clean (emits little or no greenhouse gases), reliable (average system availability of 95%), and homegrown (making us less dependent on foreign oil). Geothermal resources range from shallow ground to hot water and rock several miles below the Earth’s surface, and even farther down to the extremely hot molten rock called magma. Mile-or-more-deep wells can be drilled into underground reservoirs to tap steam and very hot water that can be brought to the surface for use in a variety of applications.

The general characteristics of geothermal energy that make it of significant importance for both electricity production and direct use include:

  • Extensive global distribution; it is accessible to both developed and developing countries.
  • Environmentally friendly nature; it has low emission of sulphur, CO2 and other greenhouse gases.
  • Indigenous nature; it is independent of external supply and demand effects and fluctuations in exchange rates.
  • Independence of weather and season.
  • Contribution to the development of diversified power sources.

Geothermal energy can be used very effectively in both on- and off-grid developments, and is especially useful in rural electrification schemes. Its use spans a large range from power generation to direct heat uses, the latter possible using both low temperature resources and “cascade” methods. Cascade methods utilise the hot water remaining from higher temperature applications (e.g., electricity generation) in successively lower temperature processes, which may include binary systems to generate further power and direct heat uses (bathing and swimming; space heating, including district heating; greenhouse and open ground heating; industrial process heat; aquaculture pond and raceway heating; agricultural drying; etc.)

It has been estimated from geological, geochemical, shallow geophysical and shallow drilling data it is estimated that India has about 10,000 MWe of geothermal power potential that can be harnessed for various purposes. Rocks covered on the surface of India ranging in age from more than 4500 million years to the present day and distributed in different geographical units. The rocks comprise of Archean, Proterozoic, the marine and continental Palaeozoic, Mesozoic, Teritary, Quaternary etc., More than 300 hot spring locations have been identified by Geological survey of India (Thussu, 2000). The surface temperature of the hot springs ranges from 35 C to as much as 98 C. These hot springs have been grouped together and termed as different geothermal provinces based on their occurrence in specific geotectonic regions, geological and strutural regions such as occurrence in orogenic belt regions, structural grabens, deep fault zones, active volcanic regions etc., Different orogenic regions are – Himalayan geothermal province, Naga-Lushai geothermal province, Andaman-Nicobar Islands geothermal province and non-orogenic regions are – Cambay graben, Son-Narmada-Tapi graben, west coast, Damodar valley, Mahanadi valley, Godavari valley etc.

Importance of tidal energy

Tidal power is a form of renewable energy that converts that natural ebb and flow of the Earth’s tides into electricity. Consider that the Earth’s tidal patterns are fairly regular, given normal weather. It would not be difficult to determine the locations most appropriate for the production of this type of tidal power. In fact, the work has already begun.

Extreme weather is a risk, especially in regions of the world where monsoons and hurricanes are prevalent, but given the proper use of science, the machines that harness tidal power can be designed to withstand such storms at extremely high tolerances. This source of energy, though not in wide use yet, has the potential to produce seemingly boundless amounts of potential energy. As long as there is water on Earth, and the Earth’s gravity continues to compete with that of the Sun and the Moon, there will be limitless tidal power available for human consumption.

Human beings have always had a fascination with tidal energy. In the past, people relied heavily upon the tides to chart sea routes and to know when and where to sail. It also helped inform them where the best spots for new trading ports were located. Presently, the energy produced by the Earth’s natural tides can be harnessed to produce massive amounts of electrical power. When scaled with human existence and life spans, tidal power can be safely considered a perpetual source of electrical energy.

Tidal power occurs because of the gravitational interactions between the moon, the sun, and the earth. These interactions will never subside in the millions of years to come. In other words, we can apply specially crafted water turbines, and other machines, in order to harness tidal energy for an infinite amount of electrical power.

There are certain regions around the world where tidal energy is the most intense and others  where activity is lower. Both types of locations can be harvested, but the high action areas will produce the most energy. Researchers are busy advocating with companies to install various kinds of water turbines, and other machines, which will effectively help generate electrical power in a sustainable manner. One of the marked advantages of applying tidal energy is the fact that one can access it without causing any amount of pollution, though with some machines, physical damage may occur. If properly managed, tidal power plants have the potential to revolutionize how humanity produces electrical energy.

 

 

 

 

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