The wheels of technology are turned by the conversion of energy from
one form into another. Thus, energy is a key element of
sustainable development. Current trends in energy supply and use are
generally unsustainable, especially when the environment is
affected by the emitted green–house gases. These are expected to double
by 2050, and increased oil demand will heighten concerns
over the security of supplies. Hence, research on green favorites should
continue vigorously. It is unfortunate that these have their
own limitations. In such a complex situation, consideration of energy
priorities in research and development should be organized
carefully, and drivers for future energy policy should be considered
very critically. This should give very careful foresight for the
viable technologies, energy efficiency, renewable energy, oil shale,
nuclear energy, hydrogen energy, in addition to any future
innovations. Energy is of vital importance for the processes of
production and manufacturing. Thus, a key element of sustainable
development.
Keywords: Energy Status; Energy Conservation; Oil Shale; Renewable Energy; Hydrogen; Fuel Cells; Energy Efficiency; Innovations
Abbreviations: CCS: Combined Cycle System; CO2
: Carbon dioxide; GHG: Green House Gas; H2
: Hydrogen; HC: Hydrocarbon; HV:
Heating Value; HVAC: Heating Ventilation Air Conditioning; ICE: Internal
Combustion Engine; JUST: Jordan University of Science and
Technology; MED: Multiple Effect Distillation; NPPs: Nuclear Power
Plants; PV: Photovoltaic; SHC: Solid Heat Carrier; STPP: Solar
Thermal Power Plant; TE: Thermoelectric; TEG: Thermoelectric Generator;
UF6: Uranium hexafluoride; UO2
: Uranium dioxide; US:
United State
Introduction
With the increase in energy demand and the expected
shortage of the fossil fuel with time the need for sustainable
resources increases. Hence, this is initially handled by using
clean fuels [1], utilization of waste heat [2-6] and adopting
different configurations [7,8], where resources and environment
are conserved. Energy is of vital importance for the processes of
production and manufacturing. Thus, a key element of sustainable
development. Energy is the convertible currency of technology.
The Wheels of technology are turned by the conversion of energy
from one form into another. Currently trends in energy supply
and use are generally unsustainable. Energy-related emissions of
CO2
are predicted to more than double by 2050, and increased oil
demand will heighten concerns over the security supplies. Figure
1 shows the percentage of the (primary) worldwide energy use
provided by liquids, natural gas, coal, nuclear and renewables from
2005 through 2035. Renewables include solar and wind power,
hydropower, geothermal power, tidal and wave power and biomass.
Figure 1: % of the World’s Energy Use by Fuel in 2005-2035
[10].
Liquids, natural gas and coal are collectively the “big three” fossil
fuels that emit GHGs when converted to energy. They constitute
about 81% of the worldwide primary energy. The actual amounts
of energy used by source are shown in Figure 2 [9].
Figure 2: Total Annual Energy Use Worldwide by Fuel (1 PWh=1012 kWh) in 2005-2035 [10].
Figure 3 shows the importance in assessing the GHG nature of a
regional economy, it’s given by CO2
/ Energy Ratio (in metric tons of
CO2
/GWh, GWh= 106 kWh) which Figure 4 shows the Global Market,
Cumulative Installed capacity by Technology. There are certain
“Green” favorites, such as solar, wind and biomass with limitations
in capturing and storing, fluctuation, high cost, and being
nonintensive. There are many exciting variants on nuclear power which
face significant risks of cost overruns, limited investment, safety
and health hazards. Petroleum and natural gas are currently the
main sources of energy. But the combustion of these hydrocarbons
contributes a large fraction of green-house gases and air pollutant
emissions. The search for an alternative fuel that provides as much
energy and is environmentally friendly has been a quest for quite
sometimes [10].
Figure 3: Annual CO2
/ Energy Ratio (in metric tons of CO2
/GWh, GWh= 106 kWh) in 2005-2035 for United States, India,
China, and the World [10].
Figure 4: The Global Market, Cumulative Installed capacity by Technology, MW.
Energy Status
Unfortunately, some countries import almost all of its energy
needs. In view of the increasing burden imposed by energy imports,
it is critical for them to look for indigenous sources of energy.
Switch to new, highly efficient and environmentally superior
energy technologies, is highly desirable. Relative contribution of
energy sources in the total energy mix over the period (2005-2020)
is show in Table 1, for a typical developing country. The typical
distribution of final energy (2000-2005) is shown in Table 2. Using
energy has a direct impact on environment due to:
Table 1: Expected Contribution of Primary Energy Sources in Total Energy Mix (2005-2020).
Table 2: Percentage Sector Distribution of Final Energy (2000-2005).
a) Effluent gases [11].
b) Warming and climate change
Viable Technologies
Viable Technologies and Resources:
a) Combined cycles [12] and cogeneration (Figure 5) [13-21]
b) Energy conservation
c) Oil shale
d) Renewable energy
e) Nuclear power
f) Hydrogen and Fuel Cells
Figure 5: Gasification plant with combined cycle [24].
Energy Conservation
Fossil fuels are at present, and will be for the following decades,
the primary source of energy for satisfying the region’s energy
demands. However, CCS already faces many challenges that are not
only related to issues such as financing demonstration projects and
integration of adequate infrastructure, but also to efficiency [22-
24]. For example, capturing and compressing CO2
would increase
the fuel needs of a coal-fired powered plant by 25-40 percent.
Therefore, efforts should be forwarded toward:
a) Utilizing higher power plant conversion efficiency
(combined cycle).
b) Exploitation of low C/H content fuels, such as natural gas.
Oil Shale
The rise of oil prices in the global market has increased the
interest in production of oil from oil shale in Estonia and other
countries as well. The greatest problem of shale oil production is
the low thermal efficiency of the process [25]. Figure 6 shows the
theoretical (retorting in standard Fischer Assay) energy balance of
thermal decomposition of oil shale organic matter, as well as the
real-life balance compiled based on the long-term experience of
shale oil production with the solid heat carrier (SHC) method at
the AS Narva Oil Plant Company [26]. Oil shale is a kerogen-rich
fine-grained sedimentary rock and its abundant reserves are the
second largest among all fossil fuels in the world if converted into
heat [27-30].
Figure 6: Energy balance of thermal decomposition of oil shale organic matter. Theoretical means energy balance by retorting
in standard Fischer Assay.
Oil Shale needs more detailed studies that handle [31-33]:
a) Realistic quantification.
b) Appropriate Technology.
c) Economics of conversion.
Jordan contains 40 billion tons of oil Shale (30 years), Each
ton oil shale contains 80-100 kg oil where Sulfur content about
4%. The heating value= ¼ HV of HC fuel, Hence one ton oil shale
=0.025 ton of HC fuel but, it’s harmful to the environment(Open
Pit Mining),results in barren land and it has a high consuming of
water: one barrel oil needs one barrel water plus intensive energy
consuming (In-situ retorting):3 barrels of oil need one barrel of fuel
[34,35].
Renewable Energy
Figure 7: Overview of renewable energy resources.
Renewable energies are sources of energy that are regenerated
continually from nature and derived directly from the sun (such as
thermal, photo-chemical, and photo-electric), indirectly from the
sun (such as wind, hydropower, and photosynthetic energy stored
in biomass), or from other natural movements and mechanisms of
the environment (such as geothermal and tidal energy). Renewable
energy does not include energy resources derived from fossil
fuels, waste products from fossil sources, or waste products from
inorganic sources [36]. Figure 7 shows an overview of renewable
energy sources [37,38].
While it is true that renewable energy sources are
environmentally friendly, or “green”, one has also to consider their
feedstock. Solar, wind, hydro, biomass and geothermal energies
are “free” at first glance, although they require huge land-use
investments with environmental unfriendly footprints especially
biomass. However, active research and development should
continue until RE become competitive on all grounds, to increase
their share in the total energy profile due to their own merits, not
due to subsidies. Renewables account for 8% of the (world) and
US national energy product as Figures 8 & 9. Most of this market is
not due to symbolic renewables of wind and solar that dominates
global discussion [39]. It is from biomass and hydroelectricity.
It is also obvious that electricity from renewable energies has
considerable problems in the way they are deployed today. First
of all, and foremost, they are dependent on certain conditions
(availability of wind, water and sunshine). Due to their intermittent
nature, this deployment method is overstraining the grid, which is
additionally rather inefficient in itself e.g. Germany. This not only
requires improving the grid, but also making it “smart”.
Figure 8: U.S renewable energy consumption (by source) 2003. The generation of electricity accounts for about one-half of the
renewable resources used.
Figure 9: U.S renewable energy consumption (by source) 2003. The generation of electricity accounts for about one-half of the
renewable resources used.
Renewable Energy (RE) - Wind
At the end of 2008, the worldwide capacity of wind-powered
generators added up to 121 GW, a mere of 1.5 percent of the world’s
electricity usage. But the rapid growth continues, with China
doubling its wind power capacity for the fifth consecutive year
since 2004 [40]. The strongest growth will be biomass and wind
towards (2035). The solar remains the perennial dark horse with
tremendous but unproven potential. Intermittency of wind turns
out to be a big problem for the grid-operating utilities, because
electricity must be used as soon as it is produced. But how easily
can be forecast when and where the wind will blow? You can’t
simply start a wind mill up when you need it most. Thus, at least as
the electricity grids are operated today, the intermittency of wind
always requires backup systems (batteries) with an equal amount
of dispatchable generation capacity. Unfortunately, at the moment
these back-up systems are mostly conventional power plants that
do not have short run-up times. In addition to the unpredictability
of wind, wind farms usually need high investments to be built, and
are also very expensive to properly maintain. At least 20 percent
of the windmills are shut off for maintenance or repairs. What
is even worse, they are often taken off the grid, because their
electricity is not needed at that given moment [41,42]. There are no
commercially viable ways to store wind energy at this time, other
than pumping up water electrically in water reservoirs. But this
only makes sense when wind farm and water reservoir are close
to each other. Moreover, wind has noise emission, effect on animal
species and birds. There are objections by the military: disturbing
microwave lengths, radar and low-flying aircrafts [43-45].
Renewable Energy- Solar
Figure 10: Scheme of Solar Thermal Power Plant (STPP)
Figure 11: Solar parabolic trough power plant with oil steam generator and MED desalination.
The amount of energy that comes from the sun is phenomenal:
If we could somehow gather all the energy that reaches the earth
on one day and store it, it would supply the energy needs of the
whole world for almost 30 years. Moreover, solar radiation is
actually the sole source for fossil or renewable energy that we use
today. Electricity from sunlight can be generated directly using
photovoltaic solar cells, or indirectly as with concentrating solar
power [46-48]. Consider another interesting aspect: PV solar
cells convert the sun’s radiation into DC power on which most of
our appliances actually run [49]. But this power is converted into
AC power by inverters and fed into the inefficient grid, only to be
inverted again to DC [50]. At this point, the most cost-effective and
efficient technology for converting solar power into electricity are
huge solar-thermal power plants (Figures 10 & 11). Here, sunlight
is gathered by a large solar-collecting field with parabolic mirrors,
so called troughs. These collectors track the sun over the course
of the day and concentrate the sunlight onto absorber pipes where
the radiation is converted into heat. A heat transfer fluid which
is circulating through the pipes is heated up to temperatures of
almost 400⁰C [51,52]. The heat is used to generate vapor or steam
with which electricity is then produced by conventional turbines.
The process fluid or water is then cooled and returned to the cycle.
The surplus heat could be used for heating, desalination, cooling,
air conditioning, and other applications, but in most cases, it is
currently rejected to the atmosphere. Solar-thermal power plants
have been in commercial use for several decades since (1982).
Thermal molten salt storage enables electricity production even
during the night, or on cloudy days. The storage time, however, is
estimated to be seven hours.
Water is mainly used for cooling the steam circuit, i.e. from the
vaporization of water in the cooling towers (about 1 million tons
water/y for 150 MW plant, 400 sq km). So, the plant operators not
only have to capture the power of the sun, but also need immense
amounts of water for cooling the heat transfer media. As most solar
power plants today is located in deserts, this physical necessity may
be an obstacle to development on the long run [53,54].
Nuclear Energy
There is now a plenty of uranium, that present reactors can
supply energy for some hundreds of years, where fossil fuels are
expected to run out in a few decades. So nuclear energy may be
considered semi-sustainable.
Using nuclear energy is assumed to limit the pollution with
greenhouse gases in an efficient and cheap way. It is the only
alternative to provide clean energy on a massive scale. However,
nuclear energy has the problem of accidents and there is still no
proper solution to store nuclear waste in a safe way [55]. Some
consider nuclear power plants to be a “clean” electricity source,
since the plants themselves do not directly emit CO2 and other
GHGs. Nevertheless, the operation of nuclear power plants results
in the immense environmental impacts which are displayed in
Figure 12. After a cost intensive exploration process, uranium ore is
recovered from the earth’s crust under quite difficult conditions. It
must be extracted from the mined ore using strong acids and bases,
and then be converted into either uranium dioxide (UO2
) for heavy
water reactors or gaseous uranium hexafluoride (UF6
) for light
water reactors [56].<.
Figure 12: Electricity from nuclear energy.
Most reactors require uranium fuel to have a U-235 (an isotope
of uranium) content of 3 to 5 percent. For this step, large amounts
of electricity, mostly provided by fossil fuel plants, are needed to
increase the actual concentration of 0.7 percent to 3 to 5 percent.
Afterwards, the uranium is manufactured into fuel pellets by
pressing powdered UO
2
or UF
6
into cylindrical shapes and baking
them at high temperatures, usually between 1,600 and 1,700⁰C.
Finally, energy is released in a reactor by controlled nuclear fission
reactions just to boil water, produce steam and drive a turbine that
generates electricity. This process alone has an efficiency of only 35
percent. For steam production and for cooling, approximately 2.5
times more water is needed for nuclear than is required for fossil
fuel plants. This is the reason why nuclear power plants are located
at rivers or lakes. In 2008, KIKK German committee reported a 60% increase in solid cancer incidence and a 120% increase
in Leukemia incidence among children living within 5 km of all
German nuclear power stations [57]. In essence, this suggests that
doses to embryos/fetuses in pregnant women from environmental
emissions from nuclear power plants (NPPs) may be larger than
suspected. It is now officially accepted in Germany that children
living near nuclear power plants develop cancer and leukemia
more frequently than those living further away [58].
After the nuclear fuel is consumed in the reaction process, it is
removed from the reactor and stored on site in large water-filled
pools for about five years. Later, the radioactive waste is transferred
to underground caverns for medium-term storage. At present,
there are no safe disposal facilities in operation anywhere in the
world which can accept radioactive waste for permanent storage
[59]. In a radioactive waste disposal facility since the seventies,
the storage has recently been found to be unstable. According to
World Nuclear News, roughly 126,000 barrels filled with lowlevel radioactive waste including contaminated clothes, paper and
equipment need to be brought to the surface for alternative storage
[60,61]. A challenge involves approximately Euro 3.7 billion and a
rather gracious heritage for future generation(s). We always need
to keep in mind that already a minor failure in a nuclear power
plant can create severe consequences for all forms of life on earth.
Accordingly, decision makers should answer the question: How
much “clean” a process like this that poses health risks exceeding
that of any other process of electricity generation?
Hydrogen and Fuel Cells
The key criteria for an ideal alternative fuel are inexhaustibility,
cleanliness, convenience, and independence from foreign control.
H2 is considered as one of the most promising fuels for generalized
use in the future. Mainly because it is versatile, energy-efficient,
low-polluting, and a renewable fuel. Hydrogen is environmentally
favorable replacement for gasoline, heating oil, natural gas, and other
fuels in both transportation and industrial applications [62-65]. In
nature, mostly the hydrogen is bound to either oxygen or carbon
atoms. Hence, to obtain hydrogen from natural compounds, energy
expenditure is needed [66-71]. Therefore, hydrogen is considered
as an energy carrier a means to store and transmit energy derived
from a primary energy source. Presently hydrogen is mainly used
in production of gasoline, fertilizers and metals. However, hydrogen
requires energy to produce, store and distribute. Hence, hydrogen
technologies need to be developed to reach the stage of competing
with fossil fuels and other alternatives to produce power [72-75].
These technologies should emphasize efficient systems to reduce
energy losses, and emissions. Among high efficiency technologies,
fuel cells appear to be the most promising with high efficiency and
very low environmental impact. Fuel cells are able to convert the
fuel chemical energy into electricity, heat and water by reverse
electrolysis. This leads to much higher conversion efficiency [76].
Fuel cells can convert the fuel chemical energy into electricity,
heat and water by reverse electrolysis, Figure 13. This leads to
much higher conversion efficiency. Both considerable primary
energies saving and pollutant reduction, are achieved by upgrading
conventional systems to fuel cell hybrid plants, Figure 13. Oil is
essential in the transport sector while natural gas will become a
more dominant fuel in power generation. Hydrogen economy is
expected to offer considerable opportunities. Fuel cell development
is an important step to the efficient use of hydrogen hence, research
must continue in this area, Figure 14. The preferable solution is to
produce H2
from sustainable sources such as, wind energy, solar
energy, waterpower or biomass. However, these energies will not
be able to provide a massive contribution to meeting the energy
demand for many decades to come: Environmental reasons (large
scale tolerance of wind energy), practical reasons (availability of
surfaces), economic reasons (cost of photovoltaic energy) and
technological reasons (storage of intermittent energies) [77].
Hence, the fuel cell is seen to be the most efficient energy converter
in the near future, using H2
. However, it still has major problems,
such as: Reducing the cost of fuel cells by a factor of 90%; enhancing
the performance and durability of fuel cell systems by a factor of 2,
and reducing the H2
production and distribution costs by a factor of
3 productions from water is not efficient [78].
Figure 13: Schematic drawing of a fuel cell.
Figure 14: Vehicle with fuel cell and hydrogen gas.
Energy Efficiency
Energy efficiency is a convenient technology to be adopted by
the developing countries. Energy conservation implies reductions
in the consumption of energy, such as (turning thermostats
down) [79]. Consuming less energy results in protection of the
environment and preventing climate change through forcing
people to make sacrifices in comfort, pleasure and convenience.
Efficiency implies obtaining more useful heat, or work from each
unit of energy supplied, either by technological improvements or
reducing waste. Consuming less energy results in protection of the
environment and preventing climate change through forcing people
to make sacrifices in comfort, pleasure and convenience [80].
Hence, Energy efficiency could be described in three ways: Less
energy for the same benefit (conservation), the same energy for a
greater benefit and more energy for an even greater benefit. Only
the first description of energy efficiency is sustainable. The second
does not lower gross energy use, and the third increases it [81].
If promoting energy efficiency, enhances the benefits of the end
users, and does not reduce the impact of energy and environmental
costs, this is not sustainable. Improved energy efficiency must lead
to measurably less gross energy use (reduced use of fossil fuels)
and polluting emissions. Improved “energy efficiency technology
“involves much more efficient: motors, air conditioners, furnaces,
direct and indirect water heaters and computers [82,83].
Variable speed drives and variable volume HVAC with direct
digital control, energy management systems with optimal start,
cogeneration and air-to-air heat pumps, reduce use of electricity
and fuel in commercial buildings [84]. For transportation, to have
lighter aluminum blocks, fuel injection, turbo charging, overhead
cams, automatic speed controls, and using unleaded fuel with
catalytic converters to reduce emissions. The bodies and frames
of the cars need to become lighter, smaller and more unified.
They are made lighter with plastics and fiberglass shaped into
aerodynamic forms. Moreover, steel belted radial tires, front wheel
drive, disk brakes with anti-lock features, light emitting diodes, all
yields a better efficiency [85]. Interstate highway systems, speed
limits legalized, carpooling, and most recently, the internet, email,
and telecommuting reduced gasoline consumption and improved
energy efficiency. In Power industry: combined cycles, cogeneration
systems, trigeneration: of power, heating and cooling enhance
energy efficiency. One-third of the oil used in most countries is used
in transportation, by passenger cars and light trucks. The overall
fuel efficiency of vehicles could be increased by improvements
primarily in aerodynamics, materials, and electronic control [86].
The most fuel-efficient cars are compact with small engines,
manual transmission, low frontal area, front wheel drive and
reduced vehicle weight. Radial tires usually reduce the fuel
consumption by 5 to 10 percent by reducing the rolling resistance.
i. Before driving:
a) Using fuel with the recommended minimum octane
number; not overfilling the gas tank.
b) Parking in the garage.
c) Starting the car properly and avoid extended idling.
d) Not carrying unnecessary weight in the vehicle.
e) Keeping tires inflated and the wheels aligned.
ii. While driving:
Avoiding quick starts and sudden stops:
a) Driving at moderate speeds.
b) Maintaining a constant speed; avoiding sudden
acceleration and sudden braking; avoiding resting feet on the
clutch or brake pedal while driving.
Using highest gear (overdrive) during highway driving; turning
the engine off rather than letting it idle; and using the air conditioner
sparingly. Regular maintenance improves performance, increases
gas mileage, lowers repair costs, extends engine life and reduces
air polluting [87].
Innovations in Energy Systems
The automobile industry and the associate industries that
serve as the base of the world’s economy and employ the greatest
share of the working population. They have played a significant role
in the growth of modern society by satisfying the need for mobility
in everyday life [88]. Presently, all vehicles rely on the combustion
of hydrocarbon (HC) fuels to derive the energy necessary for their
propulsion. Recent European green car initiatives are concentrating
on advanced internal combustion engine (ICE) research with
emphasis on:
a) new combustion techniques such as stratification with
direct injection in gasoline engines,
b) using alternative fuels (bio-methane, ethanol, hydrogen
etc.),
c) intelligent control systems,
d) mild hybridization and
e) special tires for low rolling resistance [89].
A smart Controller for improving fuel economy in vehicles was
adapted with fuel saving ~ 11% ) (Figure 15). Considering recent
fuel prices, a country of (6M people)can save: 60.0 M JD/y. The
Environment is saved proportionally, from CO2
, Figure 3.
Figure 15: Smart device in vehicles for better control of efficiency.
1.3 billion People – about 20% of the worldwide population
– are still without access to electricity, almost all of whom live
in developing countries [90]. Providing a minimum amount of
electricity can actuate the basic needs such as light, radio and
some medical electronic devices. Thus, making a lot of difference
in their lives. TEG coupled to the stove can be a very interesting
option to provide such amount of electricity. TEG is a device that
harvests waste energy and converts some of it to useful power. It
operates on a fundamental principle termed the See beck effect
which states: when a temperature gradient is established between
two different metals or semiconductors, a corresponding voltage
gradient is induced. This causes a continuous current to flow
through a complete circuit. The major advantage of a TE generator
in this case is requiring almost no maintenance, since there are no
moving parts. Only the battery needs to be charged when needed.
The TE generator works day and night in clear or rainy weather
unlike solar panels. Moreover, the battery does not need to be
oversized. On the other hand, there are some challenges involved
in using the thermoelectric generators. Mainly the low efficiency of
the technology itself is below about 10% [91] and the high price
of the TEG models. The low efficiency problem may be solved by
new technologies evolved over time. The price will decrease with
more adoption of such systems. Figure 16 shows a typical TE stoves
which offers multitasks simultaneously such as: Space heating,
cooking, heating water and generating electricity for basic needs.
Moreover, generation of water is planned in the near future [92].
Figure 16: Cross sectional view of the JUST stove [92]. Where: Tg1: Gas temperature at position 1; Tc4: Thermocouple at position
4; Tg2: Gas temperature at position2; Tc5: Thermocouple at position 5; Tg3: Gas temperature at position 3; A1: Combustor zone;
Tg4: Gas temperature at position 4; A2: After combustor zone; Tc1: Thermocouple at position 1; A3: After TEG fins zone;
Tc2: Thermocouple at position 2. A4: After cooker zone; Tc3: Thermocouple at position 3; A5: The stack.
Conclusion
Viable Technologies
Combined cycles, cogeneration, natural gas, fuel cells and
energy efficiency: Contribute toward sustainability.
Power Generation:
Presently, concentration should be made on energy efficiency
technologies. In the future, on fuel cells.
Oil Shale Needs
a) Realistic quantification
b) Appropriate technology
c) Economics of conversion: (requires huge amounts of fuel
and water)
d) Genuine assessment of environmental impacts
Renewable Energy
Green Favorites, although clean they have limitations in
capturing and storing, fluctuation, high installation cost, and are
non-intensive when converted. Active present and future research
should proceed continuously, supported by all means possible,
until RE become really competitive on all grounds, to share a
progressively higher portion of the energy pie, with gradual
replacement of fossil fuels.
Nuclear Energy
a) The nuclear energy has the problems of health hazards
(during operation), storing waste, escalating initial cost, and
accidents.
b) The risks of nuclear energy are too high for ourselves and
the many generations to come.
c) Hence, the nuclear energy should not be an easy way for
some policy makers to ensure enough energy in the future.
Hydrogen and Fuel Cells
More research and development should be concentrated on
hydrogen. Mainly because it is versatile, energy-efficient, lowpolluting, and a renewable fuel.
a) A hydrogen car is safer than NG or gasoline car in collisions
in open spaces.
b) But as safe as NG car and safer than gasoline or propane
car in a tunnel collision.
c) However, H2
economy needs more efforts to reduce the
cost of: FC, H2
production and distribution; plus, durability
enhancement.
Energy Efficiency,
a) Energy efficiency is a convenient technology to be adopted
by the developing countries.
b) Consuming less energy results in protection of the
environment and preventing climate change.
c) Efficiency implies obtaining more useful heat, or work
from each unit of energy supplied, either by technological
improvements or reducing waste.
Innovations in Energy Systems
Innovations in energy systems should continue and more
devices developed to enhance energy efficiency and sustainability
Acknowledgment
The author would like to thank Engineers Duaa MH Kharouf
and Ahmad Abu-baker for the valuable help.
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