what is polycrystalline silicon?
set of Solar PV panel and its system is very useful in the remote areas but the problem is the cost. Local people can not afford it.
The future looks great because fossil energy is polluting the environment and on the other hand requires lot of water which we don't have enough of.
What is polycrystalline silicon?
One encouraging trend relating to the future of solar energy is that many of the world's greatest innovators are choosing to focus their talents and funds on improving alternative energy technology.
The immense global energy flux from the Sun makes it the prime candidate for future sustainable energy production. Both solar thermal energy and solar photovoltaic (PV) conversion involve technologies that can be deployed on individual through community to regional scales, using both simple and advanced technologies.
You have probably seen solar PV panels that power automatic roadside weather stations and other low-drain communications systems. The panels require low maintenance and usually charge batteries to allow them to remain operational during the night. In developing countries where the energy infrastructure is rudimentary or absent, PV systems hold out great potential. An important use is for daytime pumping of water from wells.
Solar PV could theoretically supplement grid-power during daylight hours to reduce generating costs and environmental emissions. However, at this scale serious disadvantages emerge. The daily intensity of sunlight varies dramatically because of cloud cover. Moreover, solar power is greater in the summer while the demand for electricity is lower, except in areas with high use of air conditioners.
Provided photovoltaic conversion contributes no more than 10-20% of the total amount of electricity in the grid, its integration seems feasible. This is because electricity grid systems are designed to cope with large variations in demand, and they can cope equally well with fluctuations from different forms of supply.
Should future solar PV power rise above 20% of the total electricity supply, then existing grid systems built to be dominated by coal, oil and nuclear generation would have to be modified. This is because conventional power plants are slow to start up and shut down - they are slow-response systems. Solar conversion, along with other alternative sources whose power source fluctuates uncontrollably (e.g. wind and waves), is a fast-response system.
A distribution grid with solar PV power as a major component would need to be supplemented by controllable fast response systems, principally hydroelectric and gas-turbine generators. Another solution would be short-term electrical storage installations, but they are both costly and inefficient.
Despite these caveats, the potential of solar PV is enormous. If photovoltaic conversion with 10% efficiency was installed over an area of 500,000 km2 (about 1.3% of the area of tropical deserts) humanity's present energy requirements would be met.
However, that outlook is probably far off. Of the electricity generated from all alternative energy sources in the early 21st century, solar PV contributes only about 0.02%, with solar thermal generation a little more significant at 0.06%.