Such information is usually not available at meteorological stations. A mathematical model was developed to aid such analysis. The total hourly solar radiation could be estimated from the monthly averaged daily global radiation, in accordance with Duffie and Beckman (1980). Further calculations were undertaken to estimate the solar radiation falling on tilted surfaces to determine the optimum tilt angle for Qatar. The results indicated that a surface with a tilt angle of 25o would receive maximum solar radiation over the year.
The yearly estimated incident radiation on a 25o tilted surface is about 1964 kWh/m2/yr. On the other hand, the results indicate that the best tilt varies from one month to another. Table (7) and table (8) illustrate the results of the analysis according to the climate of Although the theoretical potential of PV worldwide is very high, it is difficult to quote a single figure for this potential. Of the total solar radiation reaching the earths surface each year only a minute part (about 0. 003%) is equivalent to global electricity demand today.
The potential of PV is part of the potential of all kinds of utilization of solar radiation energy. In this respect, there is no realistic limitation for this potential. Compared to wind energy, which is another and presently more economical renewable electricity source, PV has the advantage that it is not limited to certain geographic locations. PV even today is in use practically everywhere. On the other hand, the amount of radiation depends on all geography and climate, particularly on latitude. There is a difference of about a factor of 2.
5 in radiative energy between the most arid desert regions and Central Europe. A serious problem in most locations is the intermittent nature of solar energy. Examples of the daily and seasonal fluctuations of radiation are shown in Figs. 3 and 4. Figure 3 demonstrates the case of Freiburg in southern Germany, where we see a large but strongly fluctuating solar input in summer and very low availability in winter. Figure 4 in contrast gives an example of a very sunny desert climate, Doha, Qatar. Solar input is much more uniform on a daily and yearly scale.
In the first case, seasonal storage is required for an all-solar system, while in Doha daily storage is sufficient. Even in Central Europe, which is not blessed with an abundance of sun- shine, a part of electricity demand (more than 50%) could be supplied by solar electricity in theory. In reality, many obstacles will have to be overcome before even a small percentage will be reached. In more northern (or southern) countries a big problem is the seasonal mismatch of supply and demand. Significant contributions can only be expected from grid-connected systems. In this case, the grid is used for storage.
Until an economic way of seasonal energy storage becomes available, the practical limit may be about 10% of total generating capacity dependent on the elasticity of the grid. This is still a large amount of energy and very far from todays contribution. It should also be kept in mind that a combination of renewable energy sources with different stochastic like wind and PV provide a more even generating capacity. The potential for Germany has been evaluated in several studies. In very approximate terms the result is that by using all suitable roof areas, about 20% of capacity could be reached.
When comparing capacities, it should be realized that the continuous average power of a PV system is only about one tenth of peak power. Beyond roofs, other areas could also be used, like roads and rails, which could add the same amount. A still much bigger potential lies in unused agricultural areas. Further, it can be shown that by optimized mounting of PV generators the same land areas can be used, simultaneously for PV and crop cultivation. Such high levels of PV generation, however, are not very likely in the foreseeable future because seasonal storage would be required.
In climatic zones with a higher and seasonally less variable solar radiation, very high contributions of PV-electricity are possible. It is obvious that the same solar cell if mounted in a desert area close to the equator would generate 2. 0 to 2. 5 times more electricity at correspondingly lower cost than in Europe. Arguments against this are the problems of intercontinental electricity transport and of security of supply. Nevertheless, it is conceivable that in a distant future, PV farms will be set up in desert areas and the energy will be transported to the consumers by long-distance grids or in the form of hydrogen.
Qatar scenario Qatar is situated halfway along the west coast of the Arabian Gulf. It occupies an arid peninsula of 11,600 Km2. The peninsula is about 180 Km along its north-south axis, and the east-west width at its widest point is 85 Km. It lies between 24o 48³ and 26o 17³ N and between 50o 75³ and 51o 66³ E. The population estimated at about 600,000 people. The energy requirements in Qatar are met through power generation with the use of natural gas and oil. Qatar contains the third largest natural gas and the largest non-associated gas field in the world with proven reserves of 300 trillion cubic feet.
According to the year 2005 statistics, the production and consumption are estimated around 594 and 262. 4 billion cubic feet (Bcf) respectively. Oil, on the other hand, has proven reserves of 3. 7 billion barrels (2003 statistics), with rated production and consumption of 600,000 and 60,100 bbl/d respectively. Estimates indicate that gas and oil reserves will last for another 200 and 16 years respectively at the present rate of production and consumption. For the year 2006, Qatar consumed 109 thousand barrels per day of petroleum and 660 billion cubic feet of natural gas.
For that same year electricity generated amounted to 14 billion kilowatts hour and consumed 13 billion kilowatts hour (EIA, 2007). In 2005, the electric generation capacity was around 1. 86 GW and the electricity produced was around 8. 5 billion kWh. At the mentioned levels of oil and gas consumption, the total energy consumed during the year 2005 was around 8. 7 x1014 Btu. This implies that energy consumption per capita is about 1381 MBtu compared to only 354 MBtu in the United States. Energy consumption in Qatar has grown rapidly over the years,
The figure indicates that the total generated electricity has doubled during last decade. This growth can be attributed to rising population, living standards and industrialization. Almost 80% of the generated electricity is used for air conditioning. The systems hourly load in Qatar during 2005 is indicated that the peak load takes place during the summer months and at daytime. On the other hand, the generated electricity uses Natural gas and Petroleum. Fossil fuels are, however, are depleted resources and should be conserved.
Energy conservation measures such as proper insulation in buildings and promotes public awareness of the benefit of energy conservation can be adopted. Another approach is to encourage research in renewable energy resources that can be applied to the region. With the conducted experiment to gauge PV cells productivity using Qatar scenario, installation cost is very much higher than gas turbine and generation rate exhibits also the same difference. Although installation and generation cost are quite higher, still PV cells are competitive enough as to produce almost the same energy but without any fuel requirements (Riley & Meyers, 2005).
The potential contribution of PV to the overall electricity demand of a country is highly dependent on both prevailing climatic conditions and the nature of the electricity supply and demand within the country. Moreover, the peak demand of energy in Qatar is during summer months and at daytime. This indicates that solar power can be utilized instantly and eliminate the need for storage medium. But on a larger scale of production, PV cells would be at a disadvantage compared to gas turbine considering the cost of installation and higher generation cost.
At the present it would not be feasible with the current high cost of installation for PV cells and the increasing demands for generated power for the country. With a large purchase for large scale power generation it would not be economically sound when compared to fossil fuels which would seem relatively cheap (Marafia, 2001) Although on a domestic scale, for those who can afford installation of PV stand-alone unit would benefit from the generated energy in the long run. This may very well work out also for small-scale industries that specially those requiring power tools.
Although studies conducted in Mexico and Philippines indicated that it may not be economically viable to small scale industries due to the high cost of installation (Elwell & Komp, 2007). Although Qatar is one of the countries promoting the use of renewable energy, the country is still dependent on the income from its oil reserves. With the opening of Energy City in Qatar, business endeavors involving energy, primarily oil and petroleum, will be concentrated on the first energy center concentrating on the commercial, technical and human resource needs of the oil industry in the Middle East region (John, 2006b).
It is a great endeavor that these Middle Eastern countries are undertaking in their search for alternative renewable energy sources. Several countries have already undertaken the lead in utilizing these solar and wind resources. With the expected benefits to be gained from undertaking these endeavors, sustainable usage of current supply of sources of energies would yield to better sources of energy (Hirshman, 2007).
With the advancing technology regarding Solar cells and PV systems, there would come a point wherein cost of utilizing this unlimited resource would be feasible, attainable and sustainable. Lowering the cost of producing Solar cells by utilizing non-rare materials like the implementation of ultra thin silicon and dyes to increase energy captured from sunlight (Solar_Daily, 2007). It is estimated that by 2015, utilizing nanotechnology, dramatic increase in the rise of solar energy would be observed.
With continues study, it is estimated that physicist could perfect a new generation of more advance devices (Cartlidge, 2007). For Qatar, if the country is willing to bear the initial high cost of installation of these PV system then in the long run this endeavor would be beneficial in reducing the dependence on fossil fuel and generating enough power for the requirements of an advanced developing country. It would also greatly decrease the pollution emitted in our atmosphere. But with the fast pace of technological evolution, it would be more advisable to monitor these changing technology.
If prevailing PV technology is already able to meet the criteria of providing low cost power generation or at least competitive with current fossil fuel generation and durability that would make the investment sound, then there should be no doubt in giving priority to utilizing these renewable sources as primary energy generation producer to meet the countrys energy requirements. It is estimated that the widespread use of photovoltaic cells could happen as soon as 2015 if physicists can perfect a new generation of more advanced devices built using nanotechnology.
These include cells based on quantum dots or nanocrystals devices, which are potentially both cheaper and more efficient than existing cells. The promise of these technologies is very much anticipated. A report produced for the German government in 2003 predicted that by 2050 photovoltaics could be able to meet a quarter of the worlds energy needs (Cartlidge, 2007). In the long run, utilizing clean energy source would be beneficiary, not only to a countrys economy but also for the future of our societies and the entire Earth itself.
Affairs, B. o. N. E. (2007). Background Note: Qatar. Retrieved 23 January. from https://www.state.gov/r/pa/ei/bgn/5437.htm