5. Discuss briefly the ultimate origin of 3 primary energy sources we can use no

Question

5. Discuss briefly the ultimate origin of 3 primary energy sources we can use now (NOT wind, solar or fossil fuels) and the approximate timing of when and how the original energy was produced Example: fossil fuel sun constantly fusing light elements into heavier elements gaining energy from nuclear binding energies to produce light and irradiate Earth. Photosynthesis and plant growth used this energy millions of years ago and stored the it in chemical binding energy in the fossil fuels You don't need to go into detail about where all the elements on Earth come from and how the solar system and the Earth and Moon formed. But you might want to consult sources like Wikipedia, e.g. http://en.wikipedia.ora/wiki/Nucleosynthesis to get a rough idea

Explanation / Answer

1-FUEL CELLS;

INTRODUCTION
A fuel cell uses the chemical energy of hydrogen or another fuel to cleanly and efficiently produce electricity. If hydrogen is the fuel, electricity, water, and heat are the only products. Fuel cells are unique in terms of the variety of their potential applications; they can provide power for systems as large as a utility power station and as small as a laptop computer. Fuel cells can be used in a wide range of applications, including transportation, material handling, stationary, portable, and emergency backup power applications. Fuel cells have several benefits over conventional combustion-based technologies currently used in many power plants and passenger vehicles. Fuel cells can operate at higher efficiencies than combustion engines and can convert the chemical energy in the fuel to electrical energy with efficiencies of up to 60%. Fuel cells have lower emissions than combustion engines. Hydrogen fuel cells emit only water, so there are no carbon dioxide emissions and no air pollutants that create smog and cause health problems at the point of operation. Also, fuel cells are quiet during operation as they have fewer moving parts.

WORKING
Fuel cells work like batteries, but they do not run down or need recharging. They produce electricity and heat as long as fuel is supplied. A fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode (or cathode)—sandwiched around an electrolyte. A fuel, such as a hydrogen, is fed to the anode, and the air is fed to the cathode. In a hydrogen fuel cell, a catalyst at the anode separates hydrogen molecules into protons and electrons, which take different paths to the cathode. The electrons go through an external circuit, creating a flow of electricity. The protons migrate through the electrolyte to the cathode, where they unite with oxygen and the electrons to produce water and heat.

HISTORY

The concept of a fuel cell had effectively been demonstrated in the early nineteenth century by Humphry Davy. This was followed by pioneering work on what were to become fuel cells by the scientist Christian Friedrich Schönbein in 1838. William Grove, a chemist, physicist, and lawyer, is generally credited with inventing the fuel cell in 1839. Grove conducted a series of experiments with what he termed a gas voltaic battery, which ultimately proved that electric current could be produced from an electrochemical reaction between hydrogen and oxygen over a platinum catalyst. The term fuel cell was first used in 1889 by Charles Langer and Ludwig Mend, who researched fuel cells using coal gas as a fuel. Further attempts to convert coal directly into electricity were made in the early twentieth century but the technology generally remained obscure. In 1932, Cambridge engineering professor Francis Bacon modified Mend’s and Langer's equipment to develop the first AFC but it was not until 1959 that Bacon demonstrated a practical 5 kW fuel cell system. At around the same time, Harry Karl Hiriq fitted a modified 15 kW Bacon cell to an Allis-Chalmers agricultural tractor. Allis-Chalmers, in partnership with the US Air Force, subsequently developed a number of fuel cell powered vehicles including a forklift truck, a golf cart, and a submersible vessel.

2-GEOTHERMAL ENERGY

The term geothermal originates from the Greek words; Geo, which means earth and Thermal, which means heat. This derivation quickly points to the definition of geothermal energy, which is heat emanating from underneath the surface of the earth. The energy of the earth was formed by the decay of minerals and forests several years ago. Traditionally, it was used for bathing and heating purposes but today it is also used for generating electricity. It’s a renewable energy source, meaning it’s inexhaustible to humans. It’s also a green source of energy, meaning it does not emit greenhouse gasses that are hazardous to human and environmental health.

SOURCES

Scientists have constantly parted ways on the real source of heat for the generation of geothermal energy. But successive rigorous research has converged to this explanation. Approximately 4000 miles underneath the surface of the earth, this phenomenon called geothermal energy is produced deep inside the earth’s core. The earth’s core is composed of three layers; the outer silicate and solid crust, a highly viscous mantle, and a liquid outer core. The outer core consists of extremely hot magma or melted rock wrapping around a solid iron centre known as the inner core. The slow decay of radioactive material continually generates extremely high temperatures inside the earth. This is a natural process in all rocks. Wrapping around the outer core is a layer called the mantle. The mantle is approximately 1800 mils thick and mainly composed of magma and rock. The crust is the outermost layer of the earth’s core. The crust forms the bulk of continents and ocean floors that run approximately three to five miles thick beneath the oceans and 15 to 35 miles thick on the continents.

The earth’s crust is split into numerous parts known as plates. It is at the edges of these plates that magma finds way near the surface of the earth. It is in these areas that volcanoes are prevalent. When a volcano occurs, lava erupts from underneath. This lava is partly magma. Underneath the earth’s surface, the water and rocks absorb heat from the magma. As the depth increases, so do the temperatures of the underground water and rocks. Individuals across the world take advantage of the underground energy to heat their homes and generate electricity by digging up deep wells and subsequently pumping the hot underground water or steam to the earth’s surface.

How is Geothermal Energy Converted into Electricity?
Utilizing geothermal energy to generate electricity is a considerably new industry, which manifested in 1904 in Italy. Italians first powered a turbine generator using natural steam erupting from beneath the earth. The year 1960 heralded the first successful operation of the large-scale geothermal electricity generation plant at the Geysers, North California. A lot of American geothermal power plants are spread across California, while the rest are located in Hawaii, Nevada, Utah, Idaho, and Montana. The conversion of geothermal energy into electricity occurs through a geothermal power plant. The power plant harnesses the steam from the hot water beneath the earth’s surface to turn turbines, which later activates a generator to produce electricity. Some geothermal power plants utilize steam to directly turn the turbine. Others utilize the steam to heat a liquid that is used to turn the turbine.

The future of geothermal energy
geothermal energy has the potential to play a significant role in moving the United States (and other regions of the world) toward a cleaner, more sustainable energy system. It is one of the few renewable energy technologies that can supply continuous, baseload power. Additionally, unlike coal and nuclear plants, binary geothermal plants can be used as a flexible source of energy to balance the variable supply of renewable resources such as wind and solar. Binary plants have the capability to ramp production up and down multiple times each day, from 100 percent of nominal power down to a minimum of 10 percent. The costs for electricity from geothermal facilities are also becoming increasingly competitive. The U.S. Energy Information Administration (EIA) projected that the levelled cost of energy (LCOE) for new geothermal plants (coming online in 2019) will be less than 5 cents per kilowatt-hour (kWh), as opposed to more than 6 cents for new natural gas plants and more than 9 cents for new conventional coal . There is also a bright future for the direct use of geothermal resources as a heating source for homes and businesses in any location.

3-BIOMASS ENERGY

Every living animal and plant matter has some form of energy stored in it. The energy stored in these animals and plants come in the form of carbohydrates including starches, sugars, and cellulose. The carbohydrates are produced as a consequence of the photosynthesis process. Collectively, the remains of these plants and animals and the waste products organism left in the environment is referred to as organic matter. It’s quite possible to generate energy from organic matter. One technique of harnessing energy from organic matter is by producing biomass energy. Biomass energy is a renewable and sustainable source of energy derived from organic matter and can be used to generate electricity and other forms of power. Common materials that can be used to develop biomass fuel include manure, forest debris, scrap lumber, mulch, sewage, certain crops and some kinds of waste residue.

Biomass is a renewable energy because it contains the energy which comes from the sun. Biomass is basically an organic material made from plants and animals. Through the process of photosynthesis, chlorophyll present in plants absorbs the energy from the sun by converting the carbon dioxide present in air and water from the ground into carbohydrates. When these plants are burned, the same energy is released into the air they captured from the sun. Biomass in itself contains chemical energy. So, when you burn wood which is a biomass fuel, the chemical energy inside releases as heat. It can also be used to produce steam which can further be used to generate electricity. Using biomass for energy can cut back on waste and can also help in reducing the landfill. With the increase in costs, people are trying to turn to more biomass and fewer fossil fuels. Green energy production is projected to continue for many years due to the steady supply of waste emanating from construction and demolition acts, the shift from wood as a material for making paper and municipal and domestic solid waste.

It may look like that biomass helps in increasing global warming. But, in fact, it is another way around. Plants intake carbon dioxide and release oxygen into the air. When these plants decay, they are burned and carbon dioxide is released into the atmosphere. When these crops are again replanted, the new plants use the same CO2 and which was produced by the burned plants. This way biomass does not contribute towards global warming. However, if the plants are not replanted, then biomass may release carbon dioxide (CO2) which will, in turn, increase global warming.

How is Biomass Converted to Energy?
Biomass power is simply carbon neutral electricity produced from renewable organic waste products, which could have been openly burned, dumped in landfills or just left in the forest to cause fires.

1. Energy from the sun is transferred and stored in plants in the form of chemical energy. When the plants are cut or die, wood chips, straw, and other plant matter is delivered to biogas plant.

2. When biomass is burnt, it releases energy in the form of heat. If you happen to have a fireplace in your home, then you are already taking part in the utilization of biomass because the burning wood is a form of biomass fuel.

3. The biomass plants burn wood or other forms of waste to generate steam.

4. The energy from the steam is directed via pipes to run turbines.

5. The steam rises up to run turbines that eventually produce electricity or generate heat for homes and industries.

In most countries, biomass plants have been built in the countryside to provide electricity to the local population. There are waste-to-energy plants that burn trash to produce electricity and power millions of homes. Energy can also be used by burning the scrap wood or wood chips that are left over after trees have been trimmed. Advancements in technology, for instance, combustion engineering and pollution controls have led to fewer emissions in industrial settings compared to emissions from burning fossil fuel (oil, coal and natural gas) in industrial plants.

Biomass and the US

Biomass fuels provided about 4 percent of the energy used in the United States in 2010. Of this, about 46 percent was from wood and wood-derived biomass, 43 percent was from biofuels (mainly ethanol), and about 11 percent was from municipal waste. Researchers are trying to develop ways to burn more biomass and fewer fossil fuels. Using biomass for energy cuts back on waste and greenhouse gas emissions. Biomass offers other significant environmental and consumer benefits, including improving forest health, protecting air quality, and offering the most dependable renewable energy source.

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