AFFORDABLE AND CLEAN ENERGY UN DEFINATION OF AFFORDABLE

AFFORDABLE AND CLEAN ENERGY.

UN DEFINATION OF AFFORDABLE AND CLEAN ENERGY.

HYDRO-ELECTRIC ENERGY. ◦What is Hydroelectric energy? ◦Hydroelectric energy is a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity. People have used this force for millennia. Over two thousand years ago, people in Greece used flowing water to turn the wheel of their mill to ground wheat into flour. ◦How Does Hydroelectric Energy Work? ◦Most hydroelectric power plants have a reservoir of water, a gate or valve to control how much water flows out of the reservoir, and an outlet or place where the water ends up after flowing downward. Water gains potential energy just before it spills over the top of a dam or flows down a hill. The potential energy is converted into kinetic energy as water flows downhill. The water can be used to turn the blades of a turbine to generate electricity, which is distributed to the power plant’s customers.

Types of Hydroelectric Energy Plants There are three different types of hydroelectric energy plants, the most common being an impoundment facility. In an impoundment facility, a dam is used to control the flow of water stored in a pool or reservoir. When more energy is needed, water is released from the dam. Once water is released, gravity takes over and the water flows downward through a turbine. As the blades of the turbine spin, they power a generator. Another type of hydroelectric energy plant is a diversion facility. This type of plant is unique because it does not use a dam. Instead, it uses a series of canals to channel flowing river water toward the generator-powering turbines. The third type of plant is called a pumped-storage facility. This plant collects the energy produced from solar, wind, and nuclear power and stores it for future use. The plant stores energy by pumping water uphill from a pool at a lower elevation to a reservoir located at a higher elevation. When there is high demand for electricity, water located in the higher pool is released. As this water flows back down to the lower reservoir, it turns a turbine to generate more electricity.

SOLAR ENERGY. What is solar energy? ● ● ● Solar energy is the technology used to harness the sun's energy and make it useable. Many are familiar with so-called photovoltaic cells, or solar panels. The cells are made of semiconductor materials like those found in computer chips. When sunlight hits the cells, it knocks electrons loose from their atoms. As the electrons flow through the cell, they generate electricity. Application ● ● ● Solar-thermal power plants employ various techniques to concentrate the sun's energy as a heat source. To boil water Solar cookers To drive a steam turbine that generates electricity for thousands of people. Solar panels are found on things like spacecraft, rooftops, and handheld calculators.

How is solar energy harnessed? In one technique, long troughs of U-shaped mirrors focus sunlight on a pipe of oil that runs through the middle. The hot oil then boils water for electricity generation. Another technique uses moveable mirrors to focus the sun's rays on a collector tower, where a receiver sits. Molten salt flowing through the receiver is heated to run a generator. Other solar technologies are passive. For example, big windows placed on the sunny side of a building allow sunlight to heat-absorbent materials on the floor and walls. These surfaces then release the heat at night to keep the building warm. Similarly, absorbent plates on a roof can heat liquid in tubes that supply a house with hot water. Solar energy is lauded as an inexhaustible fuel source that is pollution- and often noise-free. The technology is also versatile. For example, solar cells generate energy for far-out places like satellites in Earth orbit and cabins deep in the Rocky Mountains as easily as they can power downtown buildings and futuristic cars.

GEOTHERMAL ENERGY. What is geothermal energy? ● ● ● Thermal energy is simply power derived from the Earth’s internal heat. It is contained in the rock and fluids beneath Earth’s crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma. How Is It Used? ● ● ● These underground reservoirs of steam and hot water can be tapped to generate electricity or to heat and cool buildings directly. To heat a home in the winter, while extracting heat from the building and transferring it back to the relatively cooler ground in the summer. Geothermal water from deeper in the Earth can be used directly for heating homes and offices, For growing plants in greenhouses. Geothermal hot water under roads and sidewalks to melt snow. For cooking and heating.

Production of geo-thermal energy To produce geothermal-generated electricity, wells, sometimes a mile (1. 6 kilometers) deep or more, are drilled into underground reservoirs to tap steam and very hot water that drive turbines linked to electricity generators. The first geothermally generated electricity was produced in Larderello, Italy, in 1904. There are three types of geothermal power plants: dry steam, flash, and binary. Dry steam, the oldest geothermal technology, takes steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants pull deep, highpressure hot water into cooler, low-pressure water. The steam that results from this process is used to drive the turbine. In binary plants, the hot water is passed by a secondary fluid with a much lower boiling point than water. This causes the secondary fluid to turn to vapor, which then drives a turbine. Most geothermal power plants in the future will be binary plants. Geothermal energy is generated in over 20 countries. The United States is the world’s largest producer, and the largest geothermal development in the world is The Geysers north of San Francisco in California. In Iceland, many of the buildings and even swimming pools are heated with geothermal hot water. Iceland has at least 25 active volcanoes and many hot springs and geysers.

WIND ENERGY. What is wind energy? ● ● Wind is the movement of air from an area of high pressure to an area of low pressure. As hot air rises, cooler air moves in to fill the void. Wind has long served as a power source to humans. Ancient mariners used sails to capture the wind. Farmers once used windmills to grind their grains and pump water. Today, more and more wind turbines wring electricity from the breeze. Over the past decade, wind turbine use has increased more than 25 percent per year. Still, it only provides a small fraction of the world's energy. How does it work ? ● ● ● Most wind energy comes from turbines that can be as tall as a 20 -story building and have three 200 -foot (60 -meter)-long blades. The wind spins the blades, which turn a shaft connected to a generator that produces electricity. Wind farms have tens and sometimes hundreds of these turbines lined up together in particularly windy spots.

The booming wind energy industry Wind is a clean source of renewable energy that produces no air or water pollution. And since the wind is free, operational costs are nearly zero once a turbine is erected. Mass production and technology advances are making turbines cheaper, and many governments offer tax incentives to spur windenergy development. Drawbacks include complaints from locals that wind turbines are ugly and noisy. The slowly rotating blades can also kill birds and bats, but not nearly as many as cars, power lines, and high-rise buildings do. The wind is also variable: If it's not blowing, there's no electricity generated. Nevertheless, the wind energy industry is booming. Thanks to global efforts to combat climate change, such as the Paris Agreement, renewable energy is seeing a boom in growth, with wind energy leading the way. From 2000 to 2015, cumulative wind capacity around the world increased from 17, 000 megawatts to more than 430, 000 megawatts. In 2015, China also surpassed the EU in the number of installed wind turbines and continues to lead installation efforts.

BIO ENERGY. What is Bioenergy? ● ● ● People have used biomass energy—energy from living things—since the earliest “cave men” first made wood fires for cooking or keeping warm. Biomass is organic, meaning it is made of material that comes from living organisms, such as plants and animals. The most common biomass materials used for energy are plants, wood, and waste. These are called biomass feedstocks. Biomass energy can also be a non-renewable energy source. Biomass contains energy first derived from the sun: Plants absorb the sun’s energy through photosynthesis, and convert carbon dioxide and water into nutrients (carbohydrates). ] Uses ● ● The energy from these organisms can be transformed into usable energy through direct and indirect means. Biomass can be burned to create heat (direct) Converted into electricity (direct) Processed into biofuel (indirect).

Biofuel. Hydrogen fuel cells Types of Bio-Energy Black liquor. Biochar.

◦Types of Bioenergy Biofuel. Biomass is the only renewable energy source that can be converted into liquid biofuels such as ethanol and biodiesel. Biofuel is used to power vehicles, and is being produced by gasification in countries such as Sweden, Austria, and the United States. Ethanol is made by fermenting biomass that is high in carbohydrates, such as sugar cane, wheat, or corn. Biodiesel is made from combining ethanol with animal fat, recycled cooking fat, or vegetable oil. Biofuels do not operate as efficiently as gasoline. However, they can be blended with gasoline to efficiently power vehicles and machinery, and do not release the emissions associated with fossil fuels. Ethanol requires acres of farmland to grow biocrops (usually corn). About 1, 515 liters (400 gallons) of ethanol is produced by an acre of corn. But this acreage is then unavailable for growing crops for food or other uses. Growing enough corn for ethanol also creates a strain on the environment because of the lack of variation in planting, and the high use of pesticides. Ethanol has become a popular substitute for wood in residential fireplaces. When it is burned, it gives off heat in the form of flames, and water vapor instead of smoke.

Biochar, produced during pyrolysis, is valuable in agricultural and environmental use. When biomass rots or burns (naturally or by human activity), it releases high amounts of methane and carbon dioxide into the atmosphere. However, when biomass is charred, it sequesters, or stores, its carbon content. When biochar is added back to the soil, it can continue to absorb carbon and form large underground stores of sequestered carbon—carbon sinks—that can lead to negative carbon emissions and healthier soil. Biochar also helps enrich the soil. It is porous. When added back to the soil, biochar absorbs and retains water and nutrients. Biochar is used in Brazil’s Amazon rain forest in a process called slash-and-char. Slash-and-char agriculture replaces slash-and-burn, which temporarily increases the soil nutrients but causes it to lose 97% of its carbon content. During slash-and-char, the charred plants (biochar) are returned to the soil, and the soil retains 50% of its carbon. This enhances the soil and leads to significantly higher plant growth.

Hydrogen fuel cells. Biomass is rich in hydrogen, which can be chemically extracted and used to generate power and to fuel vehicles. Stationary fuel cells are used to generate electricity in remote locations, such as spacecraft and wilderness areas. Yosemite National Park in the U. S. state of California, for example, uses hydrogen fuel cells to provide electricity and hot water to its administration building. Hydrogen fuel cells may hold even more potential as an alternative energy source for vehicles. The U. S. Department of Energy estimates that biomass has the potential to produce 40 million tons of hydrogen per year. This would be enough to fuel 150 million vehicles. Currently, hydrogen fuel cells are used to power buses, forklifts, boats, and submarines, and are being tested on airplanes and other vehicles. However, there is a debate as to whether this technology will become sustainable or economically possible. The energy that it takes to isolate, compress, package, and transport the hydrogen does not leave a high quantity of energy for practical use.

Black liquor. When wood is processed into paper, it produces a highenergy, toxic substance called black liquor. Until the 1930 s, black liquor from paper mills was considered a waste product and dumped into nearby water sources. However, black liquor retains more than 50% of the wood’s biomass energy. With the invention of the recovery boiler in the 1930 s, black liquor could be recycled and used to power the mill. In the U. S. , paper mills use nearly all their black liquor to run their mills, and the forest industry is one of the most energyefficient in the nation as a result. More recently, Sweden has experimented in gasifying black liquor to produce syngas, which can then be used to generate electricity