Реферат: The Advantages Of Photovoltaics Essay Research Paper

The Advantages Of Photovoltaics Essay, Research Paper

There are many different energy sources and many possible future energy sources. This report will explain the downsides of the current energy sources and explain the possibility of the implementation of photovoltaic cells (PVs) as our main energy source.

The idea of solar cells is not new. Since the 1970’s, tax credits have been used to help the development and implementation of PVs. Plans were announced in 1993 by the federal government and a coalition of US utilities to install 50 megawatts of solar cells between 1994 and 2000. This, however, is not nearly enough generating power(Flavin, p. 21).

Photovoltaics will remain a specialty business unless 500 megawatts of PVs are installed. If the federal government deployed the 500 megawatts on government buildings, they could cost effectively spur the PV industry. With a push from the government and the government continually popular and could possibly become common or take over the world?s energy field(Flavin, p.21).

There are a couple of main sources of energy. Coal is the largest source in terms of how much is used. Another fuel source is nuclear power. A simplified version of how coal is used to make electricity is that it is burned and this boils water. The steam from the water is then used to turn turbines which produce electricity. This is fine except for the fact that when something is burned, a chemical reaction takes place and in this case, smoke is released. This smoke contains carbon dioxide(CO2). This carbon dioxide causes global warming(Gervase).

Dan Lashof from the Natural Resources defense council, Global Warming Central said “Coal-fired power plants in 1995 were responsible for 1730 million tons of carbon dioxide, 10 million tons of sulfur dioxide, 7.8 million tons of nitrogen oxide, and 55 tons of mercury among other toxic pollutants. This makes coal-fired power plants not only the source of climate altering carbon dioxide, but also of acid rain and particulate pollution formed from the sulfur and nitrogen emissions. Along with automobiles, coal fired power plants are also a leading contributor to smog formation. (Lashof p.26)”

In short, he is saying that the burning of coal is polluting the atmosphere, is changing the climate, and causing global warming.

Global warming is becoming more accepted in society and science. Although there are tons of evidence evidence supporting global warming, some people still don’t believe that it is happening. Dan Becker, from the Global Warming Center, presents one piece of evidence: “Mr. Palmer’s claim `satellite records, weather balloons, and rural ground based temperature readings show no global warming for the last 30 years` is either misinformed or intentionally untrue. The reality is that the last 30 years have seen the warmest surface temperatures in recorded history, and they have been documented not by alarmists, but by responsible, unbiased scientists from NASA, NOAA, and countless universities and research institutions around the world(Becker, p16).

Even with punishing winter weather in the US and Europe, 1996 was one of the warmest years ever recorded. The average temperature of the first seven years of the 1990’s is already higher than the entire decade of the 1980’s. 1995 was the warmest year since humans began keeping accurate measurements of temperature! Around the world scientists are documenting the rapid melting of glaciers. Snow cover is melting much earlier in the year. Ocean temperatures have warmed, sea levels have risen almost one foot, and the patterns of deep sea currents are shifting. These are indisputable facts, recorded by responsible scientists over the last several decades.(Dan Becker, p16)” All this is saying is that there is no doubt that global warming is happening. Global warming happens because the carbon dioxide traps the sun?s energy when it reaches the earth. The sun heats the earth from the heat, radiation, and other things that are emitted by the sun. When the heat and radiation enter the earth’s atmosphere and hit the earth, they warm it up.

The angle of the earth affects how much of the energy is absorbed by the earth or reflected by it. The closer the angle is to 90 degrees, a greater percent of the energy will be absorbed. The reflected energy then goes out of the atmosphere, but with global warming, the reflected energy can’t escape. The CO2 traps the heat in the atmosphere, just like a greenhouse, hence the name greenhouse effect, which leads to global warming.

Another problem with coal is that we are depleting the coal resources at ever increasing rates. Once we have used up all of the coal reserves, there is no more coal. This isn’t good, and worse is that energy use will increase. Thomas Johansson, the professor of Energy Systems Analysis says that there will be a 265% increase in the demand for electricity between 1985 and 2050. Unless the US switches its source for electricity, then we will have a huge problem to deal with(Thomas Johansson, p 17).

Global warming will lead to a change in the climate. This change will disrupt the food chain, which is essential for all living things. Also, global warming will shrink the North American growing belt. This will cause mass food shortages, price hikes, and 400 million lives could be lost. Global warming will dry up the growing areas and will make them hotter. This will result in less precipitation, such as less rain and snow (Flavin, p19).

There is a chance of climate oscillation. This could cause plants to die. The decrease in plants could lead to the death of billions of people world wide. All of these people dying would cause people to be insecure about their own lives, and they would withdraw all their money from banks and from their stocks. This could cause another stock market crash. The unemployed people would cut back their consumption. Thus, our economy would collapse(Milbrath, p28).

There are many advantages of using photovoltaic cells instead of using coal or any other fuel. Nuclear energy is much worse than using photovoltaic cells. One way using photovoltaic cells is better is because of the proliferation of nuclear energy. There is a large chance that the proliferation of nuclear energy can be abused. However, there is very little chance that the use of photovoltaic cells could be abused because they have no known harmful side effects.

Fusion reactors pay-back-time, which is how long the reactor must be used until it produces more energy than was needed for the reaction, is 20 years and the life of the reactor is only 30 years. Therefore the reactor will have to be producing nuclear waste for 20 years until it is equal in how much energy is used and how much energy is produced. It is not reasonable to use nuclear power plants.

Oil is a large fuel source found mostly in the Middle East. If we decrease our oil dependency, then we can also decrease our defense budget. The implementation of photovoltaic cells decreases this dependency because if we don?t have to fear Middle East countries attacking us, then we don?t need as large of a defense budget.

Photovoltaics are also better because they are a renewable energy source. As Scheer said “Energy is the lifeline of any natural and societal development…All humanity is threatened with decline because the energy supply system of the 20th century has all-encompassing destructive consequences-the exhaustion of oil, coal, natural gas…The energy crisis becomes a crisis for humanity”(Scheer, p16).

Another advantage of photovoltaic cells is that there is no public or governmental opposition to the implementation. There are many signs that there is public support and support from companies. One is that there are many model houses being built that are going to put photovoltaic cells on the roof. Also, in Atlanta, the designers of the natorium were going to put photovoltaic cells on the roof (Gunther, p96).

Another advantage of using and developing photovoltaic cells is that there is a large boost to the economy. This is the effect if the government uses a small amount of money to research and test the use of highly reflective roofing and other shading techniques could lower the temperature of Los Angeles by 5 degrees. This could reduce air conditioning bills in excess of $150 million . A decrease

of 5 degrees would be like taking 3/4 of the cars off the road in terms of smog formation. The reason for this is because smog formation is very temperature sensitive. There would be savings of $300 million a year in health benefits. If this plan was carried out nationwide, there would be savings of $10 billion a year by the year 2015 (www.theatlantic.com/atlantic/issues/96apr/oil/oil.html).

?directly intercepted solar energy, at present appears to be the most sensible longer-term option. It also, quite uniquely, lacks the problems of environmental thermal pollution because the net rate of solar energy use would be balanced by the rate of solar energy interception…if all the solar energy reaching a 700 by 700 km square of land in the US into electric power at only 1% efficiency, this could meet the total electric power demands in the US today…solar energy could, incidentally, also provide a massive contribution to road transport energy needs without any significant pollution…it seems that the principal obstacle.. is not thelack of scientific knowledge and technology, but the evident lack of the now urgently needed political will, foresight, and understanding at national government levels worldwide? (Winteringham,p15).

He is saying that all we have to do to solve our energy problems is to put PVs on a 700 by 700 km square of land and we will have all the electricity we need. This is figuring on a 1% efficiency rating. Right now, using concentrators, PVs have a efficiency rating of 17% to 30% and above(www.pvpower.com/pvtechs.html).

With all of this information, it is easy to see why photovoltaics may soon be our next energy provider. They are coming down in costs, they are absolutely quiet, they cause no pollution. There is a ton of reasons why we should switch to photovoltaic cells. The only reason they are not the main energy source is the lack of government will to implement photovoltaics.

However, our government will have to find a new energy source when there is no more coal or the OPEC countries gain too much control of the world oil market. This is possible for the OPEC countries because the US accounts for 25 to 30% of total world oil use.

Bibliography

Ehrlich & Ehrlich Technology Review 1997

Flavin, Christopher Power Surge: Guide to theComing Energy Revolution1989

Flavin and Tunali, Christopher and Odil Climate of Hope 1996

Gervase, Pete source unknown

Johansson, Thomas Renewable Energy: Sources for Fuels and Electricity 1993

Lashof, Dan Global Warming Guide 1997

www.law.pace.edu/env/energy/globalwarming. html

Milbrath, Lester The Futurist 1994

Scheer, Hermann Solar Manifesto 1993

Winteringham, Energy Use and the Environment, 1992 p 15