By: Elyse Hendricks and Savanna Sheridan
Hydroelectric power is creating by force of falling water. As the water builds
up behind the dam it accumulates potential energy. This energy is transformed into
mechanical energy when it hit the rotator on the turbine. As the turbine rotates
they spin electromagnets which create a current in coils of wire. Finally the current
that is created is put through a transformer where the voltage is increased for long
distance traveling over power lines. Creating energy this way emits less pollution. It
also has a relatively low cost of maintenance. However, the dams built to capture
this energy can have a negative impacted on the environment. For example, they
can prevent fish, such as salmon, from getting up stream to reproduce. This can
cause some species of river fish to become endangered.
Monks, Young And Old, March In Protest Of Cambodian Hydroelectric Project
The latest challenge to a proposed hydroelectric project in a western Cambodian rainforest does not come from environmental groups, politicians, or local residents. It comes from monks.
Buddhist monks from Phnom Penh walked 15 miles through the jungle last week in protest of the proposed 108 megawatt Stung Cheăy Areng dam, which would reportedly result in the flooding of almost 2,000 hectares of rainforests — some of which would be forest land sacred to Buddhists. The flooding would cause more than 1,500 people to relocate, The Cambodia Daily reported.
The group of 40 monks ranged from young to old, from fit to frail. According to Al Jazeera, a number of elderly monks became overwhelmed by the trek, prompting a rescue mission from a nearby village. “As is the norm for Buddhist monks, they had not eaten since noon,” Al Jazeera’s report said. “Most had brought only a little water.”
If built, the Areng dam would be located on the edge of the Central Cardamom Protected Forest, a “biodiversity hotspot” that is home to some of Cambodia’s largest mammal species. Half of Cambodia’s reptiles, birds and amphibians live in the Cardamom forest, which also houses the only known wild-breeding population of critically endangered Siamese crocodiles, according to the Global Conservation Fund.
Environmentalist group Rainforest Rescue has said that the flooding caused by the dam will threaten the habitat of more than 277 animal species of which 31 are globally threatened. Other energy companies had studied the potential for a project there but had turned it down, the group said, adding that the costs for the dam would be very high in view of the plant’s relatively low capacity.
The proposed plant’s projected output of 108 megawatts, the group said, “would not meet Cambodia’s rising energy needs.” But Cambodia needs more sources of renewable energy, according to a recent report from the United Nations, which called the country’s current electric system unsustainable. Cambodia’s primary energy source, the UN said, is fuel-wood and imported petroleum products.
The UN report recommended the country develop a sustainable fuel wood supply and promote the use of alternative energy sources in order to combat the negative effects of climate change. However, the report also cautioned against the development of hydropower in the country, saying it might have negative impacts on agricultural lands and the productivity of fish habitats. If Cambodia were to use hydropower, the report said, it should invest in large-scale thermal and hydro power stations which “could be considered for energy export projects which would also contribute to reducing costs for domestic uses.”
When the monks arrived at the proposed dam site in Areng Valley, they blessed the surrounding forest by draping the surrounding trees in saffron sashes, the Phnom Penh Post reported. Though monks have traditionally been discouraged from involving themselves in politics, Bun Buntenh — the monk who organized the protest march — told the Post that “things don’t have to be this way.”
“I think life is created from the environment itself,” Buntenh told Al Jazeera. “If I lose part of the environment, I lose part of my life.”
The project is being proposed by China Guodian Corporation, one of the five largest power producers in the People’s Republic of China.
Pech Siyun, provincial director of Cambodia’s energy department, told Cambodia Daily in June that there is not yet a set date for construction of the dam. “The process of discussion over capital investment and some technical issues has not yet been completed,” he reportedly said.
The monk protest hydroelectric power- Article
There was a proposal for hydroelectric project in a western Cambodian rainforest.
This proposal was protested by Buddhist monks that walked 15 miles through the
jungle. If the hydroelectric plant was built it would flood approximately 2,000
hectares of rainforest which would cause more than 1,500 people to be relocated. It
would also have a negative effect on the biodiversity due to it proposed placement,
which is in the center of the “biodiversity hotspot”. The UN did recommend that the
country find a way to use more renewable resources such as fuel wood; however,
they did caution Cambodia to avoid hydroelectricity because it could potentially
have a negative impact on the agriculture.
Innovative engineering and design is turning a 30-year-old flood storage dam into a hydroelectric power producer at Jordan Dam.
The 4.4-MW Jordan Hydroelectric Project, installed on the discharge tower of a U.S. Army Corps of Engineers flood storage dam, is truly the first of its kind. The project involves the installation of two conventional vertical Kaplan turbine-generators located on the upstream side of the discharge tower.
Each turbine-generator is installed in an enclosure that seals (like a headgate) to the upstream side of the tower's intake. While the two turbines have a total discharge capacity of 1,100 cubic feet per second (cfs), the hydroelectric project controls flow releases of up to 3,100 cfs through project equipment. Above 3,100 cfs, the units are raised to allow flows to pass underneath while continuing to generate power. When flows exceed the hydraulic capacity of the hydro project, the equipment is raised to restore the full discharge capacity. The project required negligible modifications to the discharge tower and does not affect the Corps' operation of the tower or control of flow releases.
The first turbine became commercially operational in January 2012 and the second in July 2012. Many design features implemented in the Jordan Hydroelectric Project could be used at other dams that contain a similar discharge tower.
Jordan Dam in Moncure, N.C., was built in 1982 and is a rock-filled structure 113 feet high and 1,200 feet long. It is owned and operated by the Corps for flood control and water quality for the Haw River downstream. The dam is typical of many flood storage dams, with flows released from a multi-gated, rectangular concrete discharge tower and returned to the river via a non-pressurized outlet conduit. Under normal pond levels, the dam creates a 15,000-acre impoundment, with a gross head of 57.5 feet at normal pool. With the impoundment at flood control level, the tower's discharge capacity is 17,000 cfs.
Since its construction, Jordan Dam has released enough water to have generated more than 500,000 MWh of electricity. The Jordan Hydroelectric Project began to harness that energy on January 20, 2012, when the first of two turbine-generators became commercially operational.
The Jordan Hydroelectric Project consists of two vertical Kaplan turbine-generators (65-inch runner), each with a capacity of 2.2 MW under a gross head of 57.5 feet and a flow of 550 cfs, for an estimated combined annual generation of 16,900 MWh. Each turbine-generator is installed in a 180-ton steel enclosure - the power module - located on the upstream side of the discharge tower, sealing off the 12-foot-wide by 30-foot-high intake opening. The modules are 12 feet square, 77 feet tall from invert to generator floor, and 120 feet tall overall. Each module contains two 3-foot-wide by 4-foot-high spillgates to discharge flow above the turbine's capacity. The vertical synchronous generators are direct-connected, 327 rpm air-cooled units located inside an enclosure about 10 feet above normal pool level.
Licensing of the project with the Federal Energy Regulatory Commission began in 1993, with a license received in 1997 and amended in 2006 for the two-unit project. Design and construction documents were submitted to the Corps for review between October 2008 and December 2009, and the 408 Permit from the Corps was received in November 2010. On-site work began immediately with the construction of a 23-kVA transmission line to connect the facility to the local utility (Progress Energy Carolinas).
The project team included the Corps as dam owner; developer Jordan Hydroelectric Limited Partnership; structural designer Kleinschmidt Associates; designer, fabricator and lead contractor North Fork Electric Inc.; consultant Diehl Engineering Co. as marine engineer for shaft analyses and bearing requirements; turbine-generator manufacturer China Huadian Engineering Corp.; and fabricator and underwater diving contractor Grainger Underwater Services.
The modules are located upstream of the discharge tower's emergency and service gates, in the maintenance bulkhead slots. Under normal operating conditions, the head differential can vary from 57.5 to 64 feet. The modules are designed to the same criteria as the Corps' service and emergency gates and are capable of withstanding the hydrostatic loading associated with a flood pool at elevation 240 feet and the tower dewatered (a 90-foot differential).
With the impoundment at flood pool level, the generators would be 6 feet underwater. Designing the modules to withstand flood pool loadings continues to provide the tower with three levels of water shutoff. The modules are also suitable as maintenance bulkheads during repairs to the tower and its emergency and service gates.
Each turbine has a hydraulic capacity of 550 cfs, and each of the modules has two spillgates each with a hydraulic capacity of 500 cfs. The total 3,100 cfs capacity of the two modules will control the flows out of Jordan Dam 86% of the time. When discharge exceeds this capacity or the impoundment reaches the uppermost grease-lubricated bearing at elevation 223 feet, the modules are raised up to 46 feet, permitting the tower's service gates to control the flow.
Based on historical flow records, it is estimated the modules will be raised five times a year for flood releases. Initial commissioning tests have shown the turbines will operate with the modules raised up to 5 feet while passing water underneath. This will extend the generation of the units up to flows of 8,000 cfs, a flow that is exceed only 5% of the time.
The 180-ton modules are fabricated of 50 ksi structural steel, hot-dipped galvanized for corrosion protection. A module is assembled in four distinct sections (turbine, flume, intake and generator). The turbine section acts as a headgate with the turbine strapped to the upstream side, sealing against the tower's 12-foot-wide by 30-foot-high intake opening.
A structural tubing cage encloses the lower part of the turbine section to guard the draft tube from damage in the event the module is lowered onto debris sitting on the tower sill. This cage also protects the draft tube from debris when flow is discharged beneath the module in the raised position. The upstream portions of the module's turbine section are enclosed by removable steel plating to prevent the wicket gate operating mechanisms from being damaged or jammed by debris. The module bears on the tower's invert only along the downstream edge seal, 4.5 inches wide, resting on the existing steel gate sill. The module's intake section is enclosed within fixed trashracks that bear on a concrete slab and forms the roof of the existing concrete grizzly racks
Jordan Small Hydro- Articl Summary
The article talks about the Jordan Hydroelectric Project which was the first of its
kind. It was built in 1982. It was installed on the discharge tower of the U.S. Army
corps of Engineers flood storage dam. There are two Kaplan turbine-generators that
have a total discharge capacity of 1,100 cubic feet per second. This hydroelectric
project produces an average of 16,900 KWh. When the flow exceeds the capacity of
the turbines the equipment is raised so that the flow returns to normal. A structural
tubing cage encloses the lower part of the turbine section to guard the draft tube
from damage in the event the module is lowered onto debris. Licensing of the
project with the Federal Energy Regulatory commission began in 1993, with a
license received in 1997.
Hydropower is beneficial
We believe that hydroelectricity should be used as a cleaner and renewable
resource. Hydroelectricity moderate to high net energy and creates much less
pollution. Hydroelectric power plants have 80% efficiency and have an extremely
large untapped potential energy. They would reduce the cost of energy to everyone
that has access to it because it is mostly self-sufficient and requires little
maintenance. Hydroelectric dams have long life span which in turn would allow for
the cost of energy to remain low. There is no CO2 emission caused by hydroelectricity directly. The only CO2 emissions caused by a hydroelectric dam is the actual construction of the dam; however, the amount the CO2 emissions are reduced in the long run make up for the emissions during construction.