The available Green Energy and Newly Developed Solar Thermal Technology


Authors:
Andrew Wong and Karin Shih

Technology Summary:
Examine the available green energy and its pros and cons. In addition, introduce the newly developed reliable and cost efficient solar thermal technology, Ausra, Inc.


Draft Text:
The largest chain-retailer in the United States, Wal-mart, provides a wide selection of products people can choose from. However, does anyone ever take a look the origin of the production? Most of the products are manufactured in China. Products that are made in China have been marketed all around the world, and due to the large demand from the consumers and the cheap labor and materials China can offer, the number of factories has sharply increased. The increasing number of factories brings growth in China’s economy, jobs to unemployed workers, and higher profit to the country as a whole. However, these factories emit a large amount of pollution in China and the neighborhood countries such as Hong Kong. Pollutions generated by our current major source of energy, fossil fuels, has resulted many negative effects to our environment; if we do not find alternative source of energy, not only we will deplete the limited fossil fuels we have on earth, but also detrimental to our environment.

Large amount of Carbon dioxide is usually one of the causes for air pollution. From researching and personal experience, I noticed that most of the factories in China only concern with the cost of production, so they tend to use cheaper energy source. They do not know that everywhere else in the world people are seriously concerned with pollution, and air pollution is on top of the chart. Therefore, people should promote Green Energy, especially to the companies and factories in China. Green Energy is an alternative form of energy; unlike the ordinary form - fossil fuels, which includes oil, gas, coal, etc, Green Energy is a renewable energy. It generates power from the sun, wind, plants and moving water, and this is a natural way to meet our energy needs and protect the environment. Therefore, promoting Green Energy as a power source is one of the solutions to create a cleaner and more sustainable energy system. On the other hand, the ordinary form of power needs to be replaced due to many downfalls. (to fossil fuel.)

Green power is now in five commonly usage forms, wind energy, biomass, geothermal energy, solar power, and hydroelectric power. First, wind energy converts the power available in moving air into electricity. The good thing about wind power is, it does not produce air emissions, generate solid waste, or use up water. However, wind power is not capable of predicting as much energy compared to fossil fuels; in addition, it also takes up much more space. Theoretically, it can supply up to 6 ZJ (seta joules) of energy per year. It is less prediction than the sun and it cannot be relied on as a main source.

Second, biomass is energy from trees and plants. This includes crops that are grown specifically for energy production and organic wastes, such as wood residues from paper mills and methane from landfills. Biomass can capture approximately 1.8 ZJ of energy per year. Using biomass to generate electricity reduces global warming emissions. However, the downside is biomass produces solid wastes.

Third, geothermal energy uses heat from inside the earth to generate clean power. Even though geothermal is capable of producing a lot of energy, the sites that make this energy are lacking in numbers. Furthermore, major plants have to be constructed to harness this energy, which destroy the environment and it is also quite costly.
Fourth, hydroelectric power captures the energy from falling water. This type of energy source does not produce emissions or solid waste, but it can have a relatively low or high impact on the environment, depending on the specific factors such as maintenance of water flow, water quality, fish impacts, and other land use issues. Hydroelectric is probably the most widely uses of green energy today; however, it also has many downfalls. One of the main downfalls is that in order to generate power, it requires a river or moving body of water, and not all places in the world have this. In addition, this energy controls the flow of water, and it might be risky for the whole environment cycle and it might destroy the homes of aquatic life.

Lastly, solar power captures the heat and light of the sun to generate electricity. Solar energy does not produce air emissions, generate solid waste, or use up water. The energy solar power generates that is available to earth is approximately 3850 ZJ per year. It is available to everyone because there is sun everywhere on earth, it is available most of the year, and it is predictable and reliable.



There are five kinds of Green powers available for us to choose from, and from an economic stand point of view, solar energy can give us the best result due to economic efficiency. Solar energy uses solar cells to generate power, and solar cells are devices which convert solar energy directly into electricity; either directly via the photovoltaic effect, or indirectly by first converting the solar energy to heat or chemical energy. The most common form of solar cells are based on the photovoltaic (PV) effect in which light falling on a semi-conductor device produces a photo voltage. This voltage is capable of driving a current through an external circuit and thereby producing useful work.

In addition, there is a new method to produce energy in solar energy industry - Solar Thermal Power. It produces at a lower cost but in large scale. Ausra, founded in Year of 2006, is a Palo Alto, CA based company; the technology was originally conceived at Sydney University in Australia. It uses the new technology called Compact Linear Fresnel Reflector (CLFR) solar collector and steam generation system. It solves common issues in solar energy, such as energy available in cloudy days at low cost.



Reliable and Cost Efficient Solar Thermal: Ausra
Ausra’s technology use simple flat moving reflectors, which are made by glass, steel, etc., follow the path of the sun and reflect its head to the fixed pope receiver. Then the sun will shine on water and boil water directly in the receivers, producing high pressure steam. And then the high pressure steam will be stored into a place where allows thermal energy being used around the clock, no matter when there is no sun. And then the steam turns a stream turbine. Eventually power created by the stream turbine generates electricity. Since it is an eco-friendly project, the water being used to heat up into stream will be re-circulated to continue the process.

How the Technology Works: Compact Linear Fresnel Reflectors (CLFR)


Ausra estimates that its technology “capable of storing 16 hours" worth of heat could provide more than 90% of current U.S. power demand at prices competitive with coal and natural gas, The Chairman of Asura Dr. David Mills said. The solar-thermal offers as low as 10 to 11 cents per kilowatter-hour while it does not release Carbon Dioxide compared to Electricity offers 9.2 cents per kilowatt-hour along with pollution. It also estimates “100% of US electric power could be generated by 92 times 92 miles solar thermal power park”. Asura provides one of the most cost-efficiency and eco-friendly methods in energy production until now.



Since Ausra is not yet a publicly traded company, its financial statement is not public, but according to the Senate Bill in New Mexico, it costs approximately $25M to generate 50megawatt. Ausra suggests China should install a solar-thmeral grid in the desert to power its rapidly expanding economy in order to replace dominated construction of coal-fired power plants which accelerate and deepen the climate crisis, and same thing with India. The crisis can create a netgative environmental and economic impacts due to China's explosive growth in elecrtric power generation to power up large amount of factories in China.


In Economic 101, the first thing professor taught us was “resource on earth is limited.” This is exactly the situation we face today; our current source of energy, fossil fuels not only has become rare, pricy and generates large amount of pollution. Air pollution, one of the biggest pollutions we face today, has become a vital issue around the world. On top of the air pollution, people have come up with alternative source of energy, and one of them is Green Energy, which includes wind, biofuel, geothermal, hydroelectric, and solar. With the available Green Energy, people should try and help promote the usage of it, especially to developing countries such as China. Instead of using lower cost energy to generate profit, factories in China can now use economic efficient Green Energy without producing large amount of pollution. Green Energy can not only give the world cleaner air and cleaner environment, it can also raise the standard of living at developing countries.


Research Links:
Solar Cells
Ausra
Senate Bill in New Mexico
Green Engergy
Solar Energy
Geothermal Power
Wind Power
Biomass
Hydroelectricity
IDT Energy
10 Green Websites