Page 62 - Biofuels Refining and Performance

Chapter
2

Photosynthetic Plants as

Renewable Energy Sources

Ahindra Nag and P. Manchikanti

2.1 Introduction
Renewable energy is an energy resource naturally regenerated over a
short time scale derived from the sun (such as thermal, photochemical,
and photoelectric) or from other natural environment effects (geothermal
and tidal energy). It is forecasted that approximately half of the total
resources in the world will be exhausted by 2025. This survey has also
revealed that global warming and climate change are serious issues that
need immediate action. The use of fossil fuels (coal, oil, gas, etc.) con-
tributes significantly to global warming and climate change [1].
Worldwide there is strong support for renewable energy, as proven by a
number of surveys [1, 2]. In 2003, a European Commission survey across
the 15 European Union (EU) countries showed that 69% of the citizens
supported more renewable energy-related research, compared to 13% for
gas, 10% for nuclear fission, 6% for oil, and 5% for coal. Understandably,
due to the inherent recycling nature as well as environmental benefits
involved, renewable sources of energy are the solution for energy man-
agement. There is an increased investment globally in such technologies
for not only enhancing the preservation of biological resources but also
for increasing energy efficiency and pollution control [1].
Biomass is one such renewable source of energy. Out of the 1.1 10 20
kW heat generated every second by the sun, only 47% (~7 10 kWh)
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reaches the earth’s surface. Solar energy is utilized by conversion to dif-
ferent energy forms such as biomass, wind, or hydropower. Green plants
are only able to effectively use visible light of wavelength falling between

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