Solar Energy Overview

The Sun sends an almost unimaginable amount of energy towards Planet Earth – around 10 17 W (one hundred thousand million million watts). In electrical supply terms this is equivalent to the output of about one hundred million modern fossil fuel or nuclear power stations. To state it another way, the Sun provides in about an hour the present energy requirements of the entire human population for a whole year. However

some caution is needed. The majority of solar radiation falls on the world’s oceans. Some is interrupted by clouds and a lot more arrives at inconvenient times or places.

Forms of Energy are Solar in Origin :

Basically all the forms of energy in the world as we know it are solar in origin. Oil, coal, natural gas, and wood were originally produced by photosynthetic processes, followed by complex chemical reactions in which decaying vegetation was subjected to very high temperatures and pressures over a long period of time. Even the energy of the wind and tide has a solar origin; since they are caused by differences in temperature in various regions of the earth. The Sun’s radiation beamed at us day by day, year by year, and century by century is effectively free income to be used or ignored as we wish. This income is expected to flow for billions of years. Nothing is ‘wasted’ or exhausted if we don’t use it because it is there anyway. The challenge for the future is to harness such renewable energy effectively, designing and creating efficient and hopefully inspiring machines to serve humankind without disabling the planet. We must now put huge effort – technological and political – into energy systems that use the Sun’s energy more directly. It is one of the most inspiring challenges facing today’s engineers and scientists and a worthwhile career path for the next generation.

Solar Systems Advantages :

Solar systems, including solar thermal and photovoltaics, offer environmental advantages over electricity generation using conventional energy sources. The benefits arising from the installation and operation of solar energy systems fall into two main categories: environmental and socioeconomical issues. From an environmental viewpoint, the use of solar energy technologies has several positive implications:

1- Reduction of the emission of the greenhouse gases (mainly CO2, NOx) and of toxic gas emissions (SO2, particulates)

2- Reclamation of degraded land 

3- Reduced requirement for transmission lines within the electricity grid

4- Improvement in the quality of water resources

The socioeconomic benefits of solar technologies include:

• Increased regional and national energy independence
• Creation of employment opportunities
• Restructuring of energy markets due to penetration of a new technology
and the growth of new production activities
• Diversification and security (stability) of energy supply
• Acceleration of electrification of rural communities in isolated areas
• Saving foreign currency
It is worth noting that no artificial project can completely avoid some impact to
the environment. The negative environmental aspects of solar energy systems
include:
• Pollution stemming from production, installation, maintenance, and
demolition of the systems
• Noise during construction
• Land displacement
• Visual intrusion
These adverse impacts present difficult but solvable technical challenges.