Environmental engineering Energy Resources

1. Energy ResourcesEnergy ResourcesEnergy ResourcesEnergy Resources

2. Energy Resources
• Renewable Energy Resources
• Solar Energy
• Wind Energy
• Geothermal Energy
• Tidal Energy
• Wave Energy
• Hydal Energy
• Biomass
• Fuel Wood
• Solid Waste

3. History of Renewable Energy Resources
Solar Energy
•Radiation produced by nuclear fusion reactions deep in the Sun’s core.
•The Sun provides almost all the heat and light Earth receives and therefore sustains every
living being.
•Solar energy travels to Earth through space in discrete packets of energy called photons

4. • The amount of light that reaches any particular point on the ground depends
on the time of day, the day of the year, the amount of cloud cover, and the
latitude at that point.
• The solar intensity varies with the time of day, peaking at solar noon and
declining to a minimum at sunset.

5. • The total radiation power (1.4 kilowatts per square meter, called the solar
constant) varies only slightly, about 0.2 percent every 30 years. Any substantial
change would alter or end life on Earth.
• The Sun produces an enormous amount of light. It generates 3.83 × 1026 watts of
power in the form of light. In comparison, an incandescent lamp emits 60 to 100
watts of power.

6. Uses of Solar Energy
• The earliest reported use of solar energy has been attributed to Archimedes.
• According to legend, he used multiple reflectors to concentrate the energy
of the sun on Roman ships attacking Syracuse, setting them on fire.
• Other early experimenters employed mirrors to concentrate radiation, so
that metals were melted or other similar experiments performed.

7. • The possible uses of solar energy fall into three categories:
• thermal processes,
•photochemical processes, and
•photoelectric processes.

8. •In thermal processes, the radiant energy is absorbed as heat by a receiver or
receiving substance which then undergoes an increase in temperature,
vaporization, or other heat absorbing process.
•Photochemical processes are those in which light energy causes a chemical
process, and
•photoelectric processes involve a direct conversion of radiation to electrical
energy.

9. •The most commonly considered uses of solar energy are those which are classed
as thermal processes.
•They include house heating, distillation of sea water to produce potable water,
refrigeration and air conditioning, power production by solar-generated steam,
cooking, water heating, and the use of solar furnaces to produce high
temperatures for experimental studies.

10. Power Generation
• The production of mechanical or electrical energy from solar energy has
been the object of numerous studies, particularly in the nineteenth and
twentieth centuries.
• For example, Ericcson (1868-1883) developed and operated several solar-
heated hot-air engines and an engine which was operated on steam
generated in a series of parabolic trough reflectors having boiler tubes at
the foci.
• Willsie and Boyle (1902-1905) devised shallow water-tanks covered with
one or two layers of glass to heat water with solar energy; the hot water
from the tanks was used to boil sulphur dioxide, ammonia, or ether which,
in turn, ran an engine.

11. • In 1913 a Shuman-Boys solar power plant, having parabolic trough reflectors
covering one third of an acre, produced steam to run a 100-hp engine which
pumped irrigation water from the Nile River; it was abandoned during World War I
as not being economical enough to compete with other means of pumping water.

12. House Heating
• Solar house heating has received attention since 1940. In this application, heat
must be collected during sunny periods and stored for use in non-sunny periods.
• An experimental house at Massachusetts Institute of Technology employed flat-
plate, water-heating collectors. These were blackened heat-absorbing plates to
which water tubes had been soldered. They were covered with glass panes to
transmit the incoming radiation and reduce heat losses from the absorbing
plate.

13. • Hot water from the collectors was pumped either to radiant heating panels in the
house or to a large, insulated, hot-water storage tank.
• At night, or during cloudy weather, hot water was pumped from the tank to the
heating panels. An auxiliary system provided heat during periods of extended
cloudy weather when the stored heat was insufficient.

14. • A house in Dover, Mass., employed flat-plate air heaters. The heated air was used
either to warm the rooms directly or went to a storage unit consisting of cans of
chemicals.
• In the latter case, it was used to melt the chemicals. Subsequently, the chemicals
were allowed to recrystallize, giving off heat when it was needed in the rooms.
• Difficulties were encountered in maintaining the capacity of the storage unit at its
design level.

15. • In 1956, G.O.G. L"f started construction of a solar-heated house. It utilize
flat-plate air-heating collectors and a pebble-bed heat-storage unit.
This system is designed to carry about two thirds of the total heating
load for the 2,100-sq. ft. house. The collector area is approximately 650
sq. ft., and each of the two heat-storage units is 18 ft. high and 3 ft. in
diameter.

16. • Another house has been designed for the Boston area by the Solar Energy
Conversion Project of Massachusetts Institute of Technology.
• It utilize flat-plate water heaters and an insulated hot-water tank as the heat-
storage unit. It will supply about two thirds of the heat load of the house.

17. Distillation of Salt Water
• Solar distillation of sea or brackish waters to produce potable water has been
the object of much research.
• The most common type of experimental solar still utilizes a shallow pan of water
covered with a glass "roof" in the form of an inverted V.
• Solar energy heats the water, causing it to evaporate; the vapors condense on
the underside of the inclined glass covers and run down into collecting troughs
at their lower edges.
• A solar still of this type was constructed in Chile in 1872.
• It occupied an area of 51,000 sq. ft. and was used to make drinking water for
mine animals for nearly 40 years.

18. • Solar evaporation of salt brines has been practiced for centuries to recover the
salt. It is still an important process.
• More recently, progress has been made in the economic problem of obtaining
water by solar distillation cheaply enough when realistic amortization and
operating costs are considered. Some new solar stills use plastics as a means of
reducing initial costs.
• One new design, already completed, utilizes a concrete structure equipped
with a glass cover and built on the ground to reduce installation and
maintenance costs.

19. Solar Furnaces
• These devices are accurate parabolic reflectors which are mounted so that
they precisely "track" the sun and focus solar radiation on small areas.
• Thus, they concentrate the usually low-energy flux as much as 50,000 times. With
them, targets of appropriate design can be heated to high temperatures, up to
approximately 8,000°F.
• Several furnaces have been used for laboratory studies of the properties of
metals and ceramics and of various chemical reactions. The largest of these is a
paraboloid 34 ft. in diameter and utilizing a movable flat mirror to reflect
radiation into the paraboloid. It has been called a "semi-industrial" tool by its
designer and builder, F. Trombe of the Mont-Louis Laboratory in France.

20. Solar Cookers
• Studies of solar cookers for use in non-industrial areas have been made.
• Successful trials have been carried out in Mexico with those which utilize a
plastic reflector on a simple altazimuth mounting to reflect solar energy onto a
cooking vessel.
• In addition, solar pumps, consisting of flat-plate collectors which operate as
sulphur-dioxide boilers, reciprocating engines, and condensers, have been
manufactured by an Italian company and are being used experimentally in
Africa and southern California.

21. Photochemical and Photoelectric Processes
• Controlled photosynthesis, which is the growth of micro-organisms, such as algae,
under controlled conditions to increase the conversion of solar energy to
chemical energy, has been the object of studies in the United States and Japan.
Yields have been obtained which are about 20 times those of ordinary
agricultural processes.

22. • In the field of photoelectric processes, the Bell "Solar Battery" has given
conversions of solar energy to electrical energy of 11 per cent.
• It employs silicon cells; other similar developments have been made with
cadmium sulphide cells.

23. Fossil fuels
• Fossil Fuels, energy-rich substances that have formed from long-buried plants and
microorganisms. Fossil fuels, which include petroleum, coal, and natural gas,
provide most of the energy that powers modern industrial society. The gasoline that
fuels our cars, the coal that powers many electrical plants, and the natural gas that
heats our homes are all fossil fuels.

24. Formation of fossil fuels
• Fossil fuels formed from ancient organisms that died and were buried under layers
of accumulating sediment. As additional sediment layers built up over these
organic deposits, the material was subjected to increasing temperatures and
pressures. Over millions of years, these physical conditions chemically transformed
the organic material into hydrocarbons.

26. • Fossil fuels are primarily burned to produce energy. This energy is used to power
automobiles, trucks, airplanes, trains, and ships around the world; to fuel industrial
manufacturing processes; and to provide heat, light, air conditioning, and energy
for homes and businesses.

27. • About two-fifths of all energy consumed in the United States is used by industry,
one-third by homes and businesses, and about one-fourth by transportation.

28. • To provide fuel for transportation, petroleum is refined into gasoline, diesel fuel, jet
fuel, and other derivatives used in most of the world’s automobiles, trucks, trains,
aircraft, and ships. In the United States, transportation accounts for about two-
thirds of total petroleum consumption—more than two-thirds of which is burned as
automobile gasoline.

29. • In addition to direct combustion for commercial uses, fossil fuels are also burned to
generate most of the world’s electric power.
• In 2001 fossil fuel fired power plants produced 64 percent of the world’s electrical
power, down from 71 percent in the late 1970s.

30. • In 2001 the world’s remaining electricity supply was generated primarily by
hydroelectric power (17 percent) and nuclear fission (17 percent), with solar,
geothermal, and other sources accounting for a relatively small amount.

31. Skillcruise.com