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Alternative Fuel Sources: Alternative Fuel Sources: Opportunities, and Challenges
By By O (D id) M h O (D id) M h PhDPhDOmonowo (David) Momoh, Omonowo (David) Momoh, PhDPhD
IPFW Department of Computer Engineering and IPFW Department of Computer Engineering and I f ti T h l g (CEIT)I f ti T h l g (CEIT)Information Technology (CEIT)Information Technology (CEIT)
OUTLINEOUTLINE
Overview Energy Sources Electricity Generationy Conventional Fuel Sources & Sustainability
IssuesIssues Renewable Energy Technology
C l i Conclusion
ENERGY SYSTEMS EVOLUTION-OVERVIEW
Coal and crude oil were not relevant as sources of energy supplies at the end of 18th century.of energy supplies at the end of 18 century. Animal transportation, firewood, windmills and
watermills were the predominant means of energy supply systems up until then.
1776 birthed the Industrial Revolution – James W i d iWatt invented steam engine. Coal became the single most important source of
energyenergy. The steam was followed by internal combustion engine
(ICE)- by 20th century, crude oil took over as (ICE) by 20 century, crude oil took over as predominant energy source to support the increasing motorized road traffic.
ENERGY SYSTEMS EVOLUTION-OVERVIEW
As it is today Watermills replaced by large-hydro electric power stations. Watermills replaced by large hydro electric power stations. Windmills lost out but is coming back to stay – renewable
energy technology. Firewood and animal transportation lost out but they are
still being used as sources of energy in developing country. Natural gas was adopted as a source of energy after World Natural gas was adopted as a source of energy after World
War II – Energy demand rose sharply after the war. In 1960, nuclear power was added to the array of energy
sources Fossil Fuels still provide more than 85 percent of the world
energy demandenergy demand. Fossil Fuels – coal, crude oil, and natural gas.
ELECTRICITY GENERATION
Electrical Energy Primary sources of energy such as fossil fuel can be Primary sources of energy such as fossil fuel can be
converted to electricity Electricity serves as energy carrier Electricity serves as energy carrier.
ELECTRICITY GENERATION
Electrical Energy Energy from electricity can be used to perform the following :
Resistive (joule) heating – electric stove at home. Cooling and heating by powering a heat pump. Mechanical work using electrical machines such as electric motor.g
Electrical energy does not occur naturally in forms suited for practical applications.
It i ti t d th t h d 40 000 th d t It is estimated that each day 40, 000 thunderstorms worldwide result in 100 lightning strikes per second.
This can deliver about 700 megawatts (MWe) of electricity to earth surface.
This can meet the energy demand of about 750 thousand typical US residential customers.typ ca US es de t a custo e s
No one has yet figured out how to harness this lightning energy to supply electrical energy to consumers.
ELECTRICITY GENERATION
Percentage of different primary sources of fuel for electricity generation in the US:y g Fossil fuels – 71.6%
Coal 49.9%Gas 20.3%Oil 1.4%
Nuclear 20%Nuclear 20%Hydro 9%Biomass wind solar geothermal and other Biomass, wind, solar, geothermal, and other
renewables – 0.4% Fossil fuels (coal, crude oil, and natural gas) are stored ( , , g )
biomass of the ancient past.
SUSTAINABILITY ISSUE Primary sources of energy being used presently is predominantly
fossil fuel Depletion of resources as primary fuels are being exploited.p p y g p Increased exploitation of
the fossil reservoir: F i ill b Future extraction will be more and more difficult and challenging; more risky, and consequently more costly than today.
The exploitation and The exploitation and processing (conversion) of fossil fuel pose negative impacts to environment and health.
SUSTAINABILITY ISSUE
Global Warming -Greenhouse Gas (CO2 Greenhouse Gas (CO2, CH4)
ICE grossly inefficient (30-40%)
Pollution Acid rain Acid rain Liquid and gaseous
effluents resulting from incomplete combustionincomplete combustion.
Increased health risks: respiratory problems, asthmas some cancers etcasthmas, some cancers etc.
RENEWABLE ENERGY SOURCES
Renewable Energy technology is the type of energy technology that does not result in the energy technology that does not result in the depletion of the primary source of the energy system; and does not occasion serious negative system; and does not occasion serious negative impacts on the environment.
Such type of energy technology is sustainable Such type of energy technology is sustainable since anything that is renewable is sustainable.
RENEWABLE ENERGY SOURCES
Geothermal This energy source consists of the thermal energy stored in the
earth’s crust. It is the only form of renewable energy that is independent of
the sun it has its ultimate source within the earththe sun-it has its ultimate source within the earth. Heat flow from the earth core because of the massive
temperature difference between the surface and the interior –pthe temperature at the center is around 7000oC.
Maximum heat flow is found at the boundary between lithospheric boundary between lithospheric plates.
The heat flowing through the lithospheric plates surfaces average lithospheric plates surfaces average about 60 milliwatts per square meter (60 mWm-2).
RENEWABLE ENERGY SOURCES
Geothermal-Opportunities & Challenges Accessibility – this is achieved using well-established techniques
for extracting oil and gas. One or more boreholes are drilled into the reservoir, the hot fluid flows is pumped to surface and is then
sed in con entional steam t rbines or heating eq ipmentused in conventional steam turbines or heating equipment. Unlike many other renewable energy, geothermal energy is already
commercially competitive in many locations worldwide where high-commercially competitive in many locations worldwide where highgrade hydrothermal are found.
By year 2000, the world electrical power generating capacity from h l h h d l 8 i l i l (8 geothermal resources has reached almost 8 gigawatts electrical (8
GWe). The main environmental concerns facing a geothermal The main environmental concerns facing a geothermal
development is seismic risks –the exploitation can trigger earth quake
RENEWABLE ENERGY SOURCES
Biomass-Opportunities & Challenges Biomass is defined as all living plant matter as well as organic
wastes derived from plants, humans, marine life, and animals Trees, grasses, shrubs, animal dung, sewage, garbage, wood
construction residues (e g saw dusts) municipal solid waste construction residues (e.g. saw dusts), municipal solid waste (MSW) are all examples of biomass.
Biomass is found in the thin surface layer of the earth called ybiosphere
Biomass represents a tiny fraction of the total mass of the earth, it is however an enormous energy storeis however, an enormous energy store.
This energy store is continually replenished by the flow of energy from the sun through the process known as photosynthesis.g p p y
RENEWABLE ENERGY SOURCES
• Biomass constitutes a natural engine for the conversion of solar energy to high-t t th t b t d t t d d d i tlenergy content that can be stored, transported and used conveniently.
RENEWABLE ENERGY SOURCES
Bioenergy Bioenergy is the general term for energy derived from biomass
such as wood, straw or animal wastes, which were living matter relatively recently – in contrast to fossil fuels.
Such materials can be burned directly to produce heat or power Such materials can be burned directly to produce heat or power, but they can also be converted to biofuels
Charcoal and biodiesel are for example biofuels made from wood pand plant seeds respectively.
RENEWABLE ENERGY SOURCES
Biomass-Opportunities & Challenges A major incentive for investing in biomass is the potential of j g p
biomass to counter atmospheric buildup of the greenhouse CO2. The target is to ensure that the growth rate of biomass balances
the release rate of CO to the atmosphere the release rate of CO2 to the atmosphere. Per unit mass of dry biomass is more reactive to combustion and
reforming with steam than most fossil fuels. Biomass has lower energy density compared to coal or petroleum. Most biomass at the point of harvest has a high burden of
physically adsorbed moisture (up to 50% of the raw material).p y y ( p ) Consequently, extra energy is needed to dry the biomass. In overall, higher cost of biomass fuel for electricity and
transportation uses compared to those of fossil fuels lower its transportation uses compared to those of fossil fuels lower its competitiveness.
RENEWABLE ENERGY SOURCES
Solar Energy The sun is by far the most significant source of renewable energy. It is an enormous nuclear fusion reactor which converts hydrogen into helium at It is an enormous nuclear fusion reactor which converts hydrogen into helium at
the rate of 4 million tonnes (about 4x109 kg) per second. This fusion reaction results in energy radiation of about 6,000oC at the sun’s
surface. This high temperature radiation in turn induces a solar radiative flux that travels
93 millions miles (about 150 million kilometers) to reach the earth’s surface. The intensity of the different components of the solar energy flux spectrum that
reaches the earth varies according to their respective wavelength. The variation in the absorption and reflection properties of different matter
constituting the earth affect the solar flux distribution.f f f The solar flux distribution changes from the top of the atmosphere to the earth’s
surface. Most of the short wave (λ < 0.4 microns) ultraviolet radiation is absorbed in the
ozone layer (O ) in the stratosphereozone layer (O3) in the stratosphere. H2O and CO2 in the greenhouse gas layer capture a good portion of the longer
wavelength radiation (λ > 0.6 microns) in the visible and infrared region.
RENEWABLE ENERGY SOURCES
Solar Energy On average, about half of the energy incident on the extraterrestrial surface
makes it to the earth’s surfacemakes it to the earth s surface. The rest of the energy is scattered, reflected, or absorbed and re-radiated into
surface
RENEWABLE ENERGY SOURCES
Solar Energy The total solar insolation that strikes the top of the atmosphere
(extraterretrial) is called the solar constant.( ) It has a value of about 1,354 W/m2. The amount of insolation that actually reaches the surface of the earth
varies from 0 W/m2 to about 1,050 W/m2. This variation depends on the time of the day and the month of the year,
as well as the local weather and latitude of a particular location on the earth’s surface.F th US th l i l ti l l high t i th d t th t For the US, the solar insolation levels are highest in the desert southwest states of Nevada, Arizona, New Mexico, and southern California.
Solar energy resource can be categorized as follows: Thermal energy or heat collected passively or actively for space Thermal energy or heat collected passively or actively for space
conditioning buildings. Thermal energy collected and converted to electricity in solar
concentrators.co ce t ato s Direct conversion of solar energy to electricity using photovoltaic
devices.
RENEWABLE ENERGY SOURCES
Solar Thermal Electric SystemsEnergy is gyabsorbed into a high-temperature
ki fl id working fluid, such as a molten salt mixture (e g mixture (e.g. sodium and potassium nitrates) which )acts as heat transfer medium.
RENEWABLE ENERGY SOURCES
Solar Photovoltaic Power Systems
Source: http://www.leonics.com/support/article2_14j/articles2_14j_en.php
RENEWABLE ENERGY SOURCES
Solar Energy – Opportunity and Challenges About 40,000EJ (4x1022 J) of solar energy are incident on the ( ) gy
US each year. Factors affecting the effective use of solar energy to displace
fossil fuel demand:fossil fuel demand: Intermittent and seasonal variability of solar radiation. Highest solar fluxes are available around the noon period. Highest solar fluxes are available around the noon period. They can vary by a factor of two or more from month to
month depending on local cloudiness, humidity, distance t th t l h g i th iti f th to the equator, seasonal changes in the position of the sun.
The solar energy has a relatively low density compared to gy y y pchemically released energy from combusting fossil fuel.
RENEWABLE ENERGY SOURCES
Wind Energy Wind energy is an indirect form of solar energy in contrast to the gy gy
direct solar energy discussed in chapter 13. Winds are produced by uneven solar heating of the earth’s land
and sea surfacesand sea surfaces Wind energy has been used for thousands of years for milling
grain, pumping water and other mechanical applications.Wi d f h fi i l f Wind energy was one of the first non-animal sources of energy to be exploited by early civilizations.
Today, there are several hundred thousands windmills in operation yaround the world many of which are used for water pumping.
The use of wind energy as a pollution-free means of generating electricity on a significant scale is currently attracting electricity on a significant scale is currently attracting unprecedented interest world wide.
RENEWABLE ENERGY SOURCES
Wind Energy The earth’s wind systems are due to the movement of The earth s wind systems are due to the movement of
atmospheric air masses as a result of variations in atmospheric pressure
Winds can reach much higher power densities than solar irradiance-10 kW/m2 during a violent storm and over 25 kW/m2 during a hurricanekW/m during a hurricane.
The maximum terrestrial solar irradiance is about 1kW/m2.
However, a gentle breeze of 5 m/s (18 km/h, 11.2 mph) has a power density of only about 0.075 kW/m2.
On the average, the ratio of total wind power to incident solar power is on the order of two percent.
RENEWABLE ENERGY SOURCES
Wind Energy The great plains region of the US Midwest has extensive wind g p g
resources.
Source: Pacific Northwest Laboratory .
RENEWABLE ENERGY SOURCES
Wind Energy – Opportunities and Challenges If fully exploited, the resources in North Dakota and South
Dakota alone could be used to generate enough electricity Dakota alone could be used to generate enough electricity that could meet half of the current US consumption
Challenges: Winds vary in speed, hence incident energy flux varies
during the day and from season to season, and not necessarily in concert with demand for electricity.
Other than the proximity of pumped storage hydro stations, there is no sufficiently inexpensive way at present to store wind energy for future use.wind energy for future use.
The best wind fields (e.g. the Dakotas) may not be in reasonable proximity to large population centers,Thi it t th t ti f i high This necessitates the construction of expensive high-voltage transmission systems which results in large line losses of input energy.
CONCLUSION
Major Challenges Facing Renewable Technology: Costs Politics and Social Issues Storage
Pumped storage station compressed air energy storage (CAES),p gy g ( ), superconducting magnets Supercapacitors advanced batteries flywheels.