Written
by Muhammad Shahrukh
21st century holds major challenges for the world. Rising oil
prices are forcing a hard look at how we plan to meet our energy needs for the future. Continued reliance on coal and other fossil fuels also means that global
warming will continue to worsen… time is to think and ponder over…
As
the world is rapidly industrializing, emission of large quantity of heat from
different sources has raised serious concerns regarding earth’s sovereignty. On the other
hand, depleting fossil fuels from within the earth is threatening the global energy need which is increasing significantly at the rate of 2.3% each
year. In order to encounter both environmental and energy crises, electricity
power generation from waste heat sources can be considered a ray of hope for
the survival of our future generations.
OBJECTIVES
The main objective of
this project is to utilize the waste heat given off by different industrial
processes such as steel or glass production, oil refining, burning of transport
fuels and to use it for the generation of electricity. Such a measure can be a
milestone in securing the energy demand of developing countries and
providing an alternative and cost-competitive means of energy production and
utilization.
METHODS
THERMOELECTRIC
GENERATORS
Thermoelectric
generators is one of the latest technique employed to convert
the waste heat into valuable electricity. These generators consume the waste
heat to boil liquid in the pot and converts it to steam, causing rotational
moment in the turbine to produce electricity. Thermoelectric devices can also
consume the energy of sun and reduce the dependence on photovoltaic cells
whose efficiency is declining significantly. Thermoelectric devices have the
ability of lighting even a 100 watt bulb and increases car’s efficiency by 25%.
It is thought that thermoelectricity has a potential to be 100 times superior to other
technologies. The design of thermoelectric devices is such that it doesn’t involve any moving parts and can be manufactured relatively effortlessly and cost-effectively.
PIEZOELECTRIC
DEVICE
The other method which
has been successfully employed for the generation of electricity from waste
heat is by using Sound. In this
technique, heat is transformed to sound by means of thermo acoustic prime
movers in the first stage. In the second stage, sound is transformed into
electricity using "piezoelectric" devices that change pressure
into electrical current. This technology has the benefit of not creating noise pollution. The efficiency of this technology can be significantly
enhanced by optimizing the geometry and insulation of the acoustic resonator
and by injecting heat directly into the hot heat exchanger.
THERMAL
DIODES
Electricity can also be
produced from waste heat by using thermal
diodes which are capable to convert heat into electricity at a much lower
temperatures. These devices can be very useful for conserving and generating
electricity. These diodes amplify the battery lives of portable devices and
diminish the power necessities of several electronic devices.
MAGNETO
HYDRODYNAMICS (MHD)
Magneto
hydrodynamics (MHD) is a technology which creates electricity
from any heat source, by using magnets to extract electricity from
superheated charged plasmas. It is supposed that MHD systems will considerably
reduce energy costs and will offer an affordable/cost-competitive
alternate means of producing electricity. The power generation through this
technology is based on Faraday’s law of electromagnetic induction. The
efficiency of this technology is anticipated to be 60%.
ADVANTAGES
Ø There is No Additional Carbon Generation required for the electricity
production.
Ø This process generates clean, reliable and cost-effective electricity from
industrial waste. It also accelerates financial turnover by maximizing energy
efficiency and fossil fuel savings.
Ø Low cost base load electricity production
Ø Low maintenance and simple operation
Ø High system efficiency.
COST
The
approximate cost of one of the methods of converting heat into electricity via
sound using acoustic heat-engine devices is $2 million. Other university engaged in the research and development of this project was able to recoup its
purchase cost in three to four years with electricity costing about three to
four cents per KWH during that time and after their payback period, the cost
per KWH was dropped to less than a penny.
CONCLUSION
As
there is an enormous apprehension on the reserves of fossil fuel energy and as
the population is mounting at a quarter of a million people per day, the
employment of renewable sources of energy and alternate means for generating
electricity becomes much more noteworthy for securing the peaceful existence of
mankind.
So the generation of electricity from waste heat sources can definitely be a
solution to the problem.
REFERENCES
1.
Future
Bioenergy and Sustainable Land Use by R.Schubert, Earthscan publications 2010.
2.
Thermophotovoltaics:
Basic Principles and Critical Aspects of System Design by Thimas Bauer published
by Springer, 2011.
3.
Advances
in Electronic Ceramics II, Volume 30 by Shashank Priya, Anke Weidenkaff,
David.P.Norton, published by John Wiley and Sons, 2009.
4.
Renewable
Energy Sources And Emerging Technologies by Kothari Et Al.,published by PHI Learning
Pvt. Ltd.
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Tags:
ELECTRIC POWER GENERATION FROM WASTE HEAT SOURCES,
magno hydrodynamics MHD,
piezo electric devices,
thermal diodes,
thermo electric generators,
waste heat
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