Renewable Energy - Renewable energy is energy that is collected from renewable
resources, which are naturally replenished on a human timescale, such as sunlight,
wind, rain, tides, waves, and geothermal heat.
Introduction: (Summarize in Reporting)
Renewable energy resources and significant opportunities for energy
efficiency exist over wide geographical areas, in contrast to other energy sources, which
are concentrated in a limited number of countries. Rapid deployment of renewable
energy and energy efficiency, and technological diversification of energy sources, would
result in significant energy security and economic benefits.[8] It would also reduce
environmental pollution such as air pollution caused by burning of fossil fuels and
improve public health, reduce premature mortalities due to pollution and save
associated health costs that amount to several hundred billion dollars annually only in
the United States.[22] Renewable energy sources, that derive their energy from the sun,
either directly or indirectly, such as hydro and wind, are expected to be capable of
supplying humanity energy for almost another 1 billion years, at which point the
predicted increase in heat from the sun is expected to make the surface of the earth too
hot for liquid water to exist.
Sources of Renewable Energy:
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Wind power
Hydropower
Solar energy
Geothermal energy
Bio energy
Energy storage
WIND POWER
The wind is used as the prime mover that turns the wind turbines (wind mill) that is
connected to the shaft of the generator producing mechanical energy that is later
converted to electrical energy.
History & Development
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People used wind energy to propel boats along the Nile River as early as 5,000
BC. By 200 BC, simple wind-powered water pumps were used in China, and
windmills with woven-reed blades were grinding grain in Persia and the Middle
East.
The first windmill used for the production of electric power was built in Scotland in
July 1887 by Prof James Blyth of Anderson's College, Glasgow
Working Principle
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Wind power provides mechanical work on the turbine blades coupled to the gear
box for conversion from low rpm to high rpm as received by the generator in
order converting it to electrical energy. (Explained by reporter)
Wind Power Plant in Philippines
Wind power in the Philippines makes up a small percentage of the total energy output
of the Philippines. The country wind energy sector has significant potential and could
provide up to 76GW of power.
Some of the most recent developments are the Bangui Wind Farm, Burgos Wind Farm,
and Caparispisan Wind Farm in Ilocos Norte[1], the Wind Energy Power System (WEPS)
in Puerto Galera, Mindoro Oriental[2] and Pililla Wind Farm Pililla, Rizal.
Wind Power on Ilocos Norte
Advantages & Disadvantages
Advantages:
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The main advantages include an unlimited, free, renewable resource (the wind
itself), economic value, maintenance cost, and placement of wind harvesting
facilities. First and foremost, wind is an unlimited, free, renewable resource.
Next, harvesting wind power is a clean, non-polluting way to generate electricity.
Disadvantages:
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Only few areas are suitable
Constructing turbines and wind facilities is extremely expensive.
The second disadvantage is technology immaturity. [1] High cost of energy can,
in part, be addressed directly with technology innovations that increase reliability
and energy output and lower system capital expenses. Offshore wind energy
produces more energy than onshore wind energy, but costs much more to
establish. The primary costs of wind turbines include construction and
maintenance.
HYDRO POWER
This implies the use of a generator that uses falling water as the prime mover to turn the
generator shaft that provides the mechanical energy.
History and Development
The technology to take advantage of falling water and get useful mechanic
energy is old. The history of hydropower started over 2000 years ago, when water
wheels were being used by the ancient Greeks to grind grain. It was not until the Middle
Ages that the technology was spread to Europe.
Hydroelectric power was also important during the industrial revolution at the
beginning of the 1800’s and provided mechanical power for textile and machine
industries.
The first hydroelectric power plant, located in Appleton, Wisconsin, began to
generate electricity already in 1882. The power output was at about 12.5 kW. 7 years
later, in 1889, the total number of hydroelectric power plant solely in the US had
reached 200.
In the 19th century these power plants got an increased amount of commercial
attention and was built rapidly in suitable areas all over the world. 1936 marks an
important year – the largest hydroelectric power plant, the Hoover Dam, was opened
and generated 1345 MW (installed capacity later increased 2080MW) from the flowing
water in the Colorado River. Below is a picture of the Hoover Dam Hydroelectric Power
Plant.
Types of Hydropower:
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Run-of-river hydropower: a facility that channels flowing water from a river
through a canal or penstock to spin a turbine. Typically a run-of-river project
will have little or no storage facility. Run-of-river provides a continuous supply
of electricity (base load), with some flexibility of operation for daily
fluctuations in demand through water flow that is regulated by the facility.
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Storage hydropower: typically a large system that uses a dam to store water
in a reservoir. Electricity is produced by releasing water from the reservoir
through a turbine, which activates a generator. Storage hydropower provides
base load as well as the ability to be shut down and started up at short notice
according the demands of the system (peak load). It can offer enough storage
capacity to operate independently of the hydrological inflow for many weeks
or even months.
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Offshore hydropower: a less established but growing group
of technologies that use tidal currents or the power of waves to generate
electricity from seawater
Hydroelectric Power Plant in Philippines
Binga Dam
Mangat Dam
San Roque Dam
Advantages & Disadvantages
Advantages:
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As you may expect, hydroelectric power is one of the “green” and
“clean” alternative energy sources that are out there.
Hydroelectricity is very reliable energy. There are very little fluctuations in terms
of the electric power that is being use by the plants, unless a different output is
desired.
Compared to among others fossil fuels and nuclear energy, hydroelectricity is
much safer. There is no fuel involved (other than water that is).
Disadvantages:
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Interventions in nature due to damming of water, changed water flow and the
construction of roads and power lines.
Building power plants in general is expensive. Hydroelectric power plants are not
an exception to this. On the other hand, these plants do not require a lot of
workers and maintenance costs are usually low.
Limited Reserviors
SOLAR ENERGY
Most renewable energy comes from the sun.
Sunlight or solar energy, can be used directly for heating and lighting homes and other
buildings, for generating electricity, and for hot water heating, solar cooling, and a
variety of commercial and industrial uses.
2 Types:
1. Solar electricity or Photovoltaic (PV) technology converts sunlight
directly into electricity. It is the prime source of power for space vehicles. It
has also been used to power small electronics and rural and agricultural
applications.
Photovoltaic cell – is a solid-state device that converts sunlight into
energy.
2. Solar Thermal Electricity converts sun’s heat into electricity. This is
primarily used in large-scale power plants for powering cities and
communitites.
History and Development
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The history of photovoltaic energy (aka. solar cells) started way back in 1876.
William Grylls Adams along with a student of his, Richard Day, discovered that
when selenium was exposed to light, it produced electricity. An electricity expert,
Werner von Siemens, stated that the discovery was “scientifically of the most farreaching importance”. The selenium cells were not efficient, but it was proved
that light, without heat or moving parts, could be converted into electricity.
In 1953, Calvin Fuller, Gerald Pearson, and Daryl Chapin, discovered the silicon
solar cell. This cell actually produced enough electricity and was efficient enough
to run small electrical devices.
The period from the 1970’s to the 1990’s saw quite a change in the usage of
solar cells. They began showing up on railroad crossings and in remote places to
power homes.
Solar Energy is now being used as source of power in some vehicles.
Advantages & Disadvantages
Advantages:
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Solar power is pollution free and causes no greenhouse gases to be emitted after
installation
Reduced dependence on foreign oil and fossil fuels
Renewable clean power that is available every day of the year, even cloudy days
produce some power
Return on investment unlike paying for utility bills
Virtually no maintenance as solar panels last over 30 years
Disadvantages:
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High initial costs for material and installation and long ROI
Needs lots of space as efficiency is not 100% yet
No solar power at night so there is a need for a large battery bank
Solar panels are not being massed produced due to lack of material and
technology to lower the cost enough to be more affordable
GEOTHERMAL ENERGY
This form of energy uses the steam from underground springs or streams that are
produced from water that is pumped down to hot rocks deep underground as a prime
mover that turns a steam turbine connected to the shaft of generator.
History and Development
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Geothermal energy from natural pools and hot springs has long been used
for cooking, bathing, and warmth.
The first geothermal electric power generation also took place
in Larderello, with the development of an experimental plant in 1904.
Geothermal energy was used to produce electricity in 24 countries in the
early 21st century, the leaders being the United States, the Philippines,
Indonesia, Mexico, New Zealand, and Italy.
Categories:
Geothermal energy use can be divided into three categories: direct-use applications,
geothermal heat pumps (GHPs), and electric powergeneration.
Direct uses
Probably the most widely used set of applications involves the direct use of
heated water from the ground without the need for any specialized equipment. All directuse applications make use of low-temperature geothermal resources,
which range between about 50 and 150 °C (122 and 302 °F). Such low-temperature
geothermal water and steam have been used to warm single buildings, as well as whole
districts where numerous buildings are heated from a central supply source. In addition,
many swimming pools, balneological (therapeutic) facilities at spas, greenhouses,
and aquaculture ponds around the world have been heated with geothermal resources.
Geothermal heat pumps
A geothermal heat pump or ground source heat pump (GSHP) is a central
heating and/or cooling system that transfers heat to or from the ground.
It uses the earth all the time, without any intermittency, as a heat source (in the winter)
or a heat sink (in the summer). This design takes advantage of the moderate
temperatures in the ground to boost efficiency and reduce the operational costs of
heating and cooling systems, and may be combined with solar heating to form
a geosolar system with even greater efficiency. They are also known by other names,
including geoexchange, earth-coupled, earth energy systems. The engineering and
scientific communities prefer the terms "geoexchange" or "ground source heat pumps"
to avoid confusion with traditional geothermal power, which uses a high temperature
heat source to generate electricity.[1] Ground source heat pumps harvest heat absorbed
at the Earth's surface from solar energy. The temperature in the ground below 6 metres
(20 ft) is roughly equal to the mean annual air temperature[2] at that latitude at the
surface.
Electric power generation
Geothermal electric uses geothermal energy to turn a turbine and generate electricity.
The first geothermal power generator was tested in Italy in 1904. The first large-scale
geothermal electric plant in the United States began operation in 1960, operating
successfully for 30 years and producing 11 megawatts (MW) of net power. Geothermal
technologies produce about one-sixth of the carbon dioxide that a relatively clean
natural-gas-fueled power plant produces, and less than 1% of the carbon dioxide of a
fossil-fuel plant. Geothermal electric power plants can run at 90% availability, and the
hydrothermal fluids are recycled back into the earth after use.
Geothermal Plant in the Philippines
Capacity
(MW)
Status
480
Operational
30
Proposed
Mt. Sibulan-Kapatagan Geothermal Power Project
300
Proposed
Balatukan-Balingasag Geothermal Prospect
40
Proposed
Station
Makiling-Banahaw (Mak-Ban) Geothermal Power
Plant (Philippine Geothermal Production Company,
Inc.)[4]
Ampiro Geothermal Power Project
Advantages and Disadvantages
Advantages:
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Efficient (300- 500% compared to 90% of the best furnaces).
Geothermal energy is a renewable resource as long as the Earth exists.
Disadvantages:
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Electricity is still needed to operate heat pumps.
Geothermal energy using wells requires an incredible usage of water.
BIO ENERGY
Bioenergy is renewable energy from organic matter. Bioenergy is energy derived from
the conversion of biomass where biomass may be used directly as fuel, or processed
into liquids and gasses.
History and Development
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Biomass energy was the first energy source. Wood for fuel and housing helped
build civilizations
This type of energy has been used since the cave-men discovered fire.
In the 1970's, scientists became interested in the possibility of replacing fossil
fuels with biomasses.
Types of Biomass
WOOD AND AGRICULTURAL PRODUCTS Most biomass used today is home grown
energy. Wood—logs, chips, bark, and sawdust—accounts for about 44 percent of
biomass energy. But any organic matter can produce biomass energy. Other biomass
sources can include agricultural waste products like fruit pits and corncobs.
SOLID WASTE Burning trash turns waste into a usable form of energy. One ton (2,000
pounds) of garbage contains about as much heat energy as 500 pounds of coal.
Garbage is not all biomass; perhaps half of its energy content comes from plastics,
which are made from petroleum and natural gas. Power plants that burn garbage for
energy are called waste-to-energy plants. These plants generate electricity much as
coal-fired plants do, except that combustible garbage—not coal—is the fuel used to fire
their boilers.
LANDFILL GAS AND BIOGAS Bacteria and fungi are not picky eaters. They eat dead
plants and animals, causing them to rot or decay. A fungus on a rotting log is converting
cellulose to sugars to feed itself. Although this process is slowed in a landfill, a
substance called methane gas is still produced as the waste decays. New regulations
require landfills to collect methane gas for safety and environmental reasons.
ETHANOL Ethanol is an alcohol fuel (ethyl alcohol) made by fermenting the sugars and
starches found in plants and then distilling them. Any organic material containing
cellulose, starch, or sugar can be made into ethanol. The majority of the ethanol
produced in the United States comes from corn. New technologies are producing
ethanol from cellulose in woody fibers from trees, grasses, and crop residues.
BIODIESEL Biodiesel is a fuel made by chemically reacting alcohol with vegetable oils,
animal fats, or greases, such as recycled restaurant grease. Most biodiesel today is
made from soybean oil. Biodiesel is most often blended with petroleum diesel in ratios
of two percent (B2), five percent (B5), or 20 percent (B20). It can also be used as neat
(pure) biodiesel (B100). Biodiesel fuels are compatible with and can be used in
unmodified diesel engines with the existing fueling infrastructure.
Advantages and Disadvantages
Advantage:
 Biomass used as a fuel reduces need for fossil fuels for the production of heat,
steam, and electricity for residential, industrial and agricultural use.
 Biomass fuel from agriculture wastes maybe a secondary product that adds
value to agricultural crop.
 The use of waste materials reduce landfill disposal and makes more space for
everything else.
Disadvantage:
 Additional work is needed in areas such as harvesting methods.
 Some Biomass conversion projects are from animal wastes and are relatively
small and therefore are limited.
 Agricultural wastes will not be available if the basic crop is no longer grown.