Sun Energy a Solution for World Energy Needs and for Mitigating Climate Change

By Dr.  Mohammed Sa’id Berigari, Senior soil and Environmental Scientist, USA, 7/04/2012.

A relevant topic to food security & agriculture

Global warming is a real threat with enormous catastrophic implications affecting humans and all other living systems on the face of our planet including food and feed security, and fiber and timber production worldwide.   As Al Gore (2009), former Vice President of the United States, put it” to get at the roots of climate crisis, we must stop using carbon-based fossil fuels like oil and coal.” And “We have to switch to renewable energy sources like solar and wind power.”  Therefore, urgent measures are needed in addition to what is already being done now globally to combat and solve such critical 21^st century climate crisis.

 Increased CO₂ concentration in the atmosphere now at 374 ppm is due to its emissions from various sources particularly from human activities which accounts for 43.1% of climate change, the single most prevalent greenhouse gas causing global warming. The other pollutants’ contributions to climate change are:   methane 28.7%, black carbon 11.9%, halocarbons 7.8%, carbon monoxide and some organic compounds other than methane 6.7%, and nitrous oxide 3.8% (Al Gore, 2009).  

 Therefore, in this article the focus is placed on ways to solve CO₂ crisis while not losing sight on how to remedy that caused by other listed pollutants.

More energy hits the Earth from the Sun in one hour than the whole world uses in one year. The source of energy in the Sun is at its core where hydrogen is converted to helium in a thermonuclear fusion. This energy travels from the core to the surface of the Sun and is released into the space mainly as light.  The energy that reaches the Earth is in two main forms, heat and light traveling as electromagnetic waves primarily in the empty space or vacuum and amounts to 5.7x 10²⁴ Joule/year. The quantity used in photosynthesis is 3 x 10²¹ Joule/ year used in fixing 2 x 10¹¹ tons of CO₂ annually.

The quantity of the solar energy remaining in excess of that used in photosynthesis is enormous and should be utilized.    In other words < 1% of the Sun light hitting the Earth is used by terrestrial plants and the remaining > 99% is partially absorbed by material objects in warming the Earth with a good portion reflected back to the space surrounding this planet.   And the quantity of solar energy therefore is limitless based on the law of conservation of mass, that of conservation of energy, and the exchange of mass and energy according to the Einstein equation E= mc².   Where E stands for energy (Joules), m for the mass    (kilograms), and c for the speed of light which is constant at 3.00 x 10⁸ meter/second in vacuum.

The process of photosynthesis uses solar light in an endothermic reaction simply by using photons in splitting each water molecule to two atoms of hydrogen (H) and one of oxygen (O) in the living photosynthetic single or multiple cells.  Two oxygen atoms form one O₂ molecule and is released into the atmosphere as a byproduct.  The H atoms are used to reduce CO₂ molecules absorbed from the air by the cells to molecules of simple sugars.

6CO_{2 (g)} +6H₂O _{(l) +} light + Living green Cells _→ C₆H₁₂O_{6 (aq) +} 6O_{2 (g)}

This natural process of carbon fixation by plants leads to mitigating the CO₂ concentration in the atmosphere thus reducing global warming. Those simple chemical reactions occurring in living green plants and other photosynthetic cells, thus far cannot be duplicated in test tubes in the absence of living cells containing chlorophyll molecules.  Therefore, all living systems on this planet depend on photosynthesis for their food, feed and survival.

The energy I need for all metabolic processes is basically derived from oxidation of sugar molecules (exothermic reaction) in different tissues which comes from chemical energy stored in sugar molecules through the process of photosynthesis.  Other than nuclear and geothermal energies, the remaining forms of energies originate from solar energy either directly or indirectly that include chemical, electrical, mechanical, radiation, and thermal energies.  Solar energy will ultimately become the main source of energy for the entire world.

Today a technology exists to harness solar energy through compact linear Fresnel reflectors (CLFR) solar collector that reflect intensive light on water pipes in generating high pressure steam for operating turbines and thus electric power.  The water is condensed and recycled.  The entire process does not emit one molecule of pollutant, the greenhouse particles in particular.

There are giant projects using this innovation of solar energy to supply a cost-effective electrical power in Australia, USA, Jordan, and other countries.  For example 92² miles of CLFR mirrors could generate enough electrical energy to meet most of the demand of USA.  When other countries with abundant sunshine follow the suite undoubtedly fossil fuel and oil consumption for energy generation will shrink enormously which would lead to marked reduction of greenhouse gases, thus mitigate the cause of global warming.

The demand for fossil fuel, oil, and natural gas will remain high for providing the carbon skeleton or precursors for the production of millions of diverse organic compounds.  The need for such chemicals will increase with time and human population growth worldwide and it will take decades for renewable energy to replace significantly the nonrenewable sources of energies.  There will be some resistance from certain segment of the world community to choose renewable energy resources over nonrenewable resources but ultimately the law of survival of the fittest must prevail or the human race collectively will suffer the consequences of irrational choices.

Therefore, humanity can overcome the climate crisis by applying the present innovations in the field of solar energy conversion to other forms of energy especially when it is combined with wind and geothermal energies and these alternative clean energy sources are now available in tremendous quantities. The future of humanity is bright when new ideas are implemented in time and space before the forces of climate change can destroy our beautiful environment and the exquisite habitat of all living ecosystems.

References

1.      Al Gore .2009. Our Choice:  How we can solve the climate crisis. Melcher Media and Penguin Group (USA) Inc.

2.      Al Gore .2009. Our Choice:  A plan to solve the climate crisis.  Melcher Media.

3.      Mills, D. and R. Morgan. 2007. Solar thermal electricity as the primary replacement for coal and oil in U.S. generation and transportation.  Ausra Inc.: 1-6.

4.      http://en.wikipedia.org.