LOWER SIXTH - KGP SCHEDULE, WEEKS 2-9 - ENERGY
MODULE 1 THE DYNAMICS OF CHANGE
10.2 PEOPLE AND THE ENVIRONMENT -POPULATION AND RESOURCES
RENEWABLE ENERGY - HEP
NON-RENEWABLE ENERGY -OIL
   
SOLAR ENERGY
Solar power is a perfect example of a renewable source being harnessed in the aim of liberating energy. The idea of being able to harness electrical energy from the sun's radiation was first introduced in 1839 by the French physicist Becquerel, he discovered that a small amount of electrical energy was produced when light fell upon certain materials. By 1891 the dream of a pollution free energy was already being conjured, a writer of the time, R.Appleyard stated;
'the blessed vision of the sun, no longer pouring his energies unrequited into space, but by means of photo electric cells .. these powers gathered into electrical storehouses to the total extinction of steam engines, and the utter repression of smoke'
Although this view was premature, as steam engines were to come into their element in the coming century it still shows how the potential of this environmentally friendly source was recognised.
SOLAR POWERS EFFECT ON THE ENVIRONMENT The beauty of the solar power system is the fact that it is a renewable source i.e. it is a source that will never run out. As solar power does not release any gas into the environment or another by-products of the harnessing of the source results in an almost negligible amount of pollution to the environment. Unlike oil, gas, coal and even nuclear which are classified as non-renewable sources there little adverse affects to the environment. The non- renewable sources can and have often had serious adverse affect on the atmosphere and the environment, events such as 'global warming', urban smog, nuclear accidents and acid rain and the removal of such disasters only heightens solar power's importance.
In my view the only effect on the environment is perhaps 'visual' pollution. In order for the power to be harnessed the photoelectric cells and other methods need to be placed in areas of maximum potential, this means the placing of instruments on top of houses and 'farms'. The units are perhaps not the most attractive of sights but I feel that this fact is small in comparison to other factors.
METHODS OF UTILISATION As shown by the presentation, there are several ways in which the power of the sun is harnessed for example, heliostats, parabolic dishes, parabolic troughs or solar cell generators. Light can be used in several ways it can be directly transferred from light energy to an induced electrical current or it can be used to heat water. The benefits of heating water results in a reduced amount of energy required to bring that water to temperature, in this case solar power acts as a supplement to other sources of energy however it reduces the amount of the other source required.(the diagram below is an example of that. In their early stages solar cells were only about 1% efficient however now they can reach peaks of up to 20% efficiency, most solar cells in current use operate at about 7-16% efficiency.
DISTRIBUTION OF SOLAR UTILISATION Of the radiant energy reaching the top of the atmosphere, 46 per cent is absorbed by the earth's surface on average, but this value varies significantly from place to place, depending on cloudiness, surface type and elevation. If there is persistent cloud cover, as exists in some equatorial regions, much of the incident solar radiation is scattered back to space and very little is absorbed by the Earth's surface. This information helps us to understand the distribution of solar utilisation. In countries such as England for example the use of solar power is limited as there simply isn't enough light to make the process viable therefore we rely more heavily on more efficient, high outputting non-renewable sources.
Areas of high temperatures generally benefit from the use of solar power for example the Mojave Desert, California USA and in Spain, both having large solar power plants. This uneven distribution results in a problem with the source as it means that it does not act as a viable option for many countries and therefore it will not be the factor that will succeed the fossil fuels as they start to run down. The presentation highlights the areas in which solar power is most beneficial and actively harnessed.
SOLAR OUTPUT The problem with solar power is that getting cost effective energy from solar cells has proved a major scientific challenge. Even with the latest solar ell technology, PV generated electricity still costs four to tens times as much as that produced from fossil fuels. A limitation of the source is that it is really only viable as a 'top up' to decrease the demand for another source. The costs, which are needed to produce the converting materials to harness the power, are high, these costs will go down as the source becomes more 'mass produced' but this will only benefit again several countries.
BIBLIOGRAPHY
ENVIRONMENT AND PEOPLE MICHAEL WITHERICK PROBLEM
SOLVING GEOGRAPHY DAVID SMITH AND NORMAN LAW
RENEWABLE ENERGY - HEP
NON-RENEWABLE ENERGY -OIL