Hydro Water Power

What is hydropower?
5 reasons why we should use hydropower
The Problems with Hydropower
Is Hydropower Viable?

Wave Power
Challenges faced with wave power
Advantages of wave power
Wave power technology
Is wave power cost effective?

Tidal Power
Benefits of tidal power generation
Producing electricity Using Tidal power
The main disadvantages of tidal power

Hydro Water Power

Energy in water (in the form of kinetic energy, temperature differences or salinity gradients) can be harnessed and used. Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy.

There are many forms of water energy:

Hydroelectric energy is a term usually reserved for large-scale hydroelectric dams. Examples are the Grand Coulee Dam in Washington State and the Akosombo Dam in Ghana. Micro hydro systems are hydroelectric power installations that typically produce up to 100 kW of power. They are often used in water rich areas as a Remote Area Power Supply (RAPS).

There are many of these installations around the world, including several delivering around 50 kW in the Solomon Islands. Damless hydro systems derive kinetic energy from rivers and oceans without using a dam. Ocean energy describes all the technologies to harness energy from the ocean and the sea.

Marine current power, similar to tidal stream power, uses the kinetic energy of marine currents. Ocean thermal energy conversion (OTEC) uses the temperature difference between the warmer surface of the ocean and the colder lower recesses. To this end, it employs a cyclic heat engine. OTEC has not been field-tested on a large scale. Tidal power captures energy from the tides. Two different principles for generating energy from the tides are used at the moment -  1. Tidal motion in the vertical direction - Tides come in, raise water levels in a basin, and tides roll out. Around low tide, the water in the basin is discharged through a turbine, exploiting the stored potential energy. Tidal motion in the horizontal direction - or tidal stream power. Using tidal stream generators, like wind turbines but then in a tidal stream. Due to the high density of water, about eight-hundred times the density of air, tidal currents can have a lot of kinetic energy. Several commercial prototypes have been build, and more are in development. Wave power uses the energy in waves. Wave power machines usually take the form of floating or neutrally buoyant structures which move relative to one another or to a fixed point. Wave power has now reached commercialization. Osmotic power or salinity gradient power, is the energy retrieved from the difference in the salt concentration between seawater and river water. Reverse electrodialysis (PRO) is in the research and testing phase. Vortex power is generated by placing obstacles in rivers in order to cause the formation of vortices which can then be tapped for energy.  Deep lake water cooling, although not technically an energy generation method, can save a lot of energy in summer. It uses submerged pipes as a heat sink for climate control systems. Lake-bottom water is a year-round local constant of about 4 °C.

Wave Farms Expansion

Portugal now has the world's first commercial wave farm, the Agucadoura Wave Park, officially opened in September 2008. The farm uses three Pelamis P-750 machines generating 2.25 MW.Initial costs are put at €8.5 million. A second phase of the project is now planned to increase the installed capacity to 21MW using a further 25 Pelamis machines.

Funding for a wave farm in Scotland was announced in February, 2007 by the Scottish Government, at a cost of over 4 million pounds, as part of a £13 million funding packages for ocean power in Scotland. The farm will be the world's largest with a capacity of 3MW generated by four Pelamis machines.

Hydroelectric Dams

The major advantage of hydroelectric systems is the elimination of the cost of fuel. Other advantages include longer life than fuel-fired generation, low operating costs, and the provision of facilities for water sports. Operation of pumped-storage plants improves the daily load factor of the generation system. Overall, hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy, and areas with abundant hydroelectric power attract industry.

However, there are several major disadvantages of hydroelectric systems. These include: dislocation of people living where the reservoirs are planned, release of significant amounts of carbon dioxide at construction and flooding of the reservoir, disruption of aquatic ecosystems and birdlife, adverse impacts on the river environment, potential risks of sabotage and terrorism, and in rare cases catastrophic failure of the dam wall.

Hydroelectric power is now more difficult to site in developed nations because most major sites within these nations are either already being exploited or may be unavailable for other reasons such as environmental considerations.

Green Alternative Energy & Renewable Energy Resources

Green Alternative Energy & Renewable Energy Resources

What is green alternative energy?

Renewable energy is just that, an energy source that can be used over and over again, energy generated from natural resources from the world around us.

You are likely familiar with most of the renewable green energy resources, as these in recent years have enjoyed a sustained growth as we seek to find more power from natural energy resources in an effort to move on from the constant use of fossil fuels, which damage our global ecosystems.

The most common green alternative energy / natural energy resources are sunlight (solar), wind, rain, tides and geothermal heating. According to recent figures '06 approximately 18 percent of worldwide final energy was provided by natural energy renewables, around 13% of this natural energy came from biomass fuels (wood and natural matter). The next largest supply of natural alternative green energy came from Read more

Is wave power cost effective?

The idea of an alternative method of a renewable energy source is the constant debate of world leaders to date. Facing damaging consequences to the earth’s normal atmospheric status, the drive to develop a cleaner more infinite form of energy is the most widely discussed issue.

While understanding the mechanisms of wave power technology, this discussion toys with the question of if wave power is cost effective. Some world economist believe no cost should be spared to preserve the earth’s vitality while others feel a more economical approached should be measured when determining the method of renewable power.

So at what cost should the world spare to make this energy concept a reality? Energy conservationists ponder this hindering question on a daily basis and the world’s economy is the deciding factor to technological advancements and keeps the development of certain renewable energy projects at bay.

There are 4 main components to which decide the economies ability to withstand a large cost for the betterment of a greater good. In other words will the cost to reproduce water power generators out weigh the overall good that will come from its production?

World economist work on financial structures to help calculate this formula and weigh in the four components to reach an overall cost efficiency for a specific project; such as the global cost for wave generator construction, the overhead for operation, the cost to perform routine maintenance and repair on faulty or damaged generators and the ability to provide wave generated power at a low enough rate to the consumer which is competitive but will not under seed the cost to operate.

The cost to construct wave generators can reach well in the hundreds of billions of dollars; from the cost of materials to the architectural designing as well as the man power to build these operational facilities thus generating an even greater strain on an already over drawn economy.

Furthermore the cost to effectively operate these wave generators with the appropriate man power and/or automated systems to monitor the daily functions, can also reach astronomical figures. These two factors combined with an agreeable rate of service, makes the determination of whether wave power will be cost effective.

Because the development of this new age renewable power source is still evolving at a slow rate, placing its potential for public consumption years behind solar and wind powered devices, it may take years before wave power energy resources will become fully developed and operational for use by the entire world.

Until technology can catch up the concept of wave powered energy, the question of “Is wave power cost effective still remains the on going topic for renewable energy sources and currently unanswered.

Wave power technology

In order to understand wave power technology, you must first understand the power it requires to produce a single wave. To put it simply, waves are the combination of airstream’s and solar influences that produce an effect on the oceans surface. This effect propels the oceans current to make the water surface actively buckle causing a wave. Waves travel at a rate per kilometer and increases during seasonal transitions. Typically wave rates are at their highest during the winter, particularly during storms.

Scientists have revealed methods of harnessing the power of waves to generate a renewable source of electrical energy. The methods of capturing this power is through wave powered generators. There are three forms of wave power generators Air columns, Hinge or Axis rafts and Hydraulic Devices. These main types of generators can either be shoreline based or free floating and each have their own uniquely designed source of producing and infinite amount of electrical power. All three forms are more commonly employed in the South western regions where the wave potentials are greater.

Air columns also referred to as oscillating water systems are shoreline based generators which are partially submerge under the oceans surface. This generator uses empty shafts to compress or decompress air flow. This air flow is produced by the surge of water under the tubes, which cause air to become trapped within the air columns and thereby causing the trapped air to propel turbines which in turn generates electricity.

Hinge or Axis rafts also known as buoyant mooring devices are more commonly designed as free floating anchored generators. This electrical generating system relies on the resistance and surrender concept, in which a portion of the generator is allowed to move with the flow of waves while the anchored portion of the generator must remain still. The effects of the two operating systems cause friction and thereby creating electrical currents.

A hydraulic or gyroscopic system is found primarily under the waters surface and performs at a deeper depth than the other generators. Although this system functions much like the resistance and surrender concept; it principal role is based upon more resistance that uses the movement of the waves to set in motion fluid within the hydraulic pumps to make electricity.

Although these systems my sound simple, the mechanisms of production for these generators are currently up for debate. While the concept of wave power technology can produce an unlimited supply of renewable energy, the problem for mass production is the cost forecast for future development in a variety of ocean and wave conditions. While the devices currently in use have proven the probability of the systems endurance to harsh ocean conditions, the prediction to produce wave generators has become increasingly difficult since their economical goal is to maintain a low overhead, maintenance and operational cost as well as not to effect the consuming population financially, which will one day rely on its electricity producing capabilities.

Advantages of wave power

According to the House of Legislation reports comprise from studies conducted by the Department of Business and Economic Development. These reports reveal a short list of advantages to wave power as a form of a renewable energy source.

The consensus is the general however widely agreed upon globally that wave power energy is the latest technique in energy conservation, and Wave Energy conversion systems or WECS have become the newest introduction to renewable power sources. While studies are still confined to specific regions of the globe; predominately areas where the wave potentials are much higher, the development of this power is still underway and has not reach its marketable prospective.

World leaders agree the need for a more economical structured renewable system is greatly desired yet fact still remains the cons currently out weigh the pro’s for wave power technology.

The abundance of wave power is without question one of the highest levels of infinite renewable sources. For over 200 years scientist have worked on innovative mechanisms to exploit the power of the ocean for the development of continual sources of energy. For that reason the implications for the potential of WECS as a source of renewable natural energy are immense. Not to mention the cost per wattage can be greatly reduced through the commercial use of the WECS and converters.

Scientist are optimistic that once the full scope and development plans are under way, electricity could cost penny’s on the dollar, approximating an average cost of lower than .05 cent per watt usage.

With the introduction to wave power energy the development of an assortment of wave power systems is considered an advantage to the commercial usage of the WECS. These electrical converters have the potential to generate electricity in a variety of ways, from compression and decompression methods to include friction emission as well as hydraulically powered forms will soon open the gate way for a more cost effective mechanisms for future public use.

Since WECS or wave power generators have the diversity of sustaining either a on or off shore location, this enhances the probability of the success of wave power energy. Furthermore the free floating and submersible version that are anchored to the oceans floor can provide greater electrical emission and the potential to capture this energy is improved.

Although the WECS is under great scrutiny for the multiple disadvantages as well as the uncompleted stages of development, legislator’s and economist alike will soon to come to an agreement, which will enable commercial development and usage of this energy source. Couple with the understanding that having a variety of renewable energy sources much like Solar and conventional wind powered mechanisms, the advantages of wave power potential will eventually out-weigh the disadvantages.

Challenges faced with wave power

The wave power industry is truly a remarkable source of infinite renewable power. And while its concept is driven by the tremendous advantages of its technology, the WECS industry must confront a number of relevant challenges. The challenges that confront wave power must first be addressed and solutions provided in order to make available a more competent mechanism. These tasks must be accomplished before wave power technology will be recognized as an effective source of renewable energy.

Many of the challenges surrounding wave powered energy focuses on the cost to develop and facilitate global resources. The primary goal is to construct a system which will reduce the cost of development and increase the availability at the lowest amount feasible. Additional factors such as the efficiently of the electrical converter system to include the levels of improvement coupled with mapping ideal location to facilitate wave powered generators has become additional issues that need to be addressed in efforts to combat the challenges the wave power systems will face.

The primary focus which surrounds the economical factors as it relate to the cost in the development of wave power generators is the biggest challenge this system faces. Understanding the materials needed to supply power, requires a system which is cost effective and will be the first challenge WECS will have to surmount. Once an effective cost can be agreed-upon the global construction of wave powered electrical converters can be strategically placed throughout ocean locations.

But before construction can begin, legislators and other Ecological specialist must categorize prime locations for the electro-converters. Since prime marine locations are determined by the highest velocity of wave production, facility determination will have to include provisions for marine locations that do not meet the wave production requirements. This issue will hinder production in areas of low wave production and may cost more to administer electrical services in these specific regions. Plus developers will have to manage systematic problems as they relate to connecting to pre-established utilities grids.

To effectively procure viable wave powered locations, scientist must conduct studies to determine the long term effect cause on oceanic life forms and the development of the oceans ecosystem. There are few studies that direct attention to these specific effects and/or if any effects will be present through the usage of a wave power system. Not to mention studies must also show how these water generators will withstand the variances in ocean conditions throughout seasonal transitions.

Because the development of WECS is so new, very little research has been conducted along with minimal viable case studied information gather over a period of time, therefore it is hard to determine just how effective WECS will be for future commercial use. Wave power energy will go through a variety of transitions and face hurdles before it is deemed a global renewable source of energy.

The main disadvantages of tidal power

In the modern world, we have seen a shift from traditional method of generating power to a more contemporary one.  And the one that is the center of attention these days is the tidal power.  Favorite amongst the scientist, this energy source is really making its presence felt in the world of energy source and power generation.  No doubt, it comes with a lot of advantages but distance drums always sound well and this is also the case with the tidal power, as with advantages it also has a lot of disadvantages.

The following are some of the disadvantages of tidal power that should be looked upon with utmost care.

• Tidal power is not all cost effective as it seems to be in the first place compared to natural gas and coal plants generating power. More so, the power stations in turn also add up to the carbon content of the atmosphere as fossil fuel is needed to run these power stations. Besides, wild life is displaced from their regular habitat.

• Tidal power cannot be generated inland and can be used where there is appropriate wave motion or tidal flow. It can only produce electricity when there is a tidal surge, not every time.

• Barrage system of tidal power generation requires a lot of maintenance and salt resistant parts. These barrages disrupt fish migration and at the same time kill some of them while they try to pass through the turbine frames. Besides, they disrupt the movement of ships through channels on which barrage is built.

• Tidal power is limited, as the tide never slows down or speeds up and at the same time occurs in cycles of 6 hours. Besides, tidal power is also dependent on fetch distance and hardly any suitable fetch distance is available and wherever available, the cost rises to almost 1.2 billion in setting up the facility.

• Technology is yet not developed fully and hence construction of efficient, cheap and strong conversion device is a bit problematic.

• Location is also one of the major problems as appropriate tides are not found everywhere. More so, tides are dispersing energy sources, lopsided and irregular in size, durability and distance.

Fossil fuels can be produced anywhere, but as mentioned above tidal power is locale specific and needs to be transformed to something different to be transported.

The above points are quite a testimonial to the fact that, there are a number of disadvantages to tidal power. No doubt, until and unless some techniques are developed to get rid of all the problems and cost factors associated with it, it may not be as cost effective to make it viable as a usable source of energy. However, the time is not far when the technologies would be developed and we would be able to come up with a better answer and solutions to all the problems.

Producing Electricity Using Tidal Power

Tidal power or tidal energy is one of the important conventional sources of energy. It is produced from the energy of the tides which is converted into electricity. At present we are not able utilize it for maximum benefits but in near future, tidal power will be one of the important source of electricity generation. Besides, we can predict tides more easily than solar power or wind energy. Not only was that, from very ancient times tide mills used in Europe and Atlantic coast of USA. The earliest being during middle Ages or even Roman times.

Tidal power generation
Tidal power is generated from the tides which are produced due to the relative motion of the earth and moon and to a very small extent due to the Earth-Sun system. This is the only source of energy which is generated from the motions of the earth and moon. Other sources of energy like fossil fuels, bio-fuels, solar power, and wind power, wave power and hydroelectric originate from Sun either directly or indirectly.

For the generation of the Tidal energy gravitational forces play the major role. Gravitational attraction of the Sun and the Moon are responsible for the rise and fall of the water levels and the production of the tidal currents. The level of the tide at any location depends upon

The change in the position of the Sun and the Moon relative to the Earth
Effects of the rotation of the earth and
The shape of the coastlines and sea floors

• Types of tidal power

• Tidal power is classified as:

Tidal stream system which uses the kinetic energy of the flowing water to supply power to the turbines. The method is popular because of its cost effectiveness and lower ecological impacts.
Barrages which uses the potential energy of the difference in the head between low and high tides. Barrages are basically dams which are built across a tidal estuary. They are not that much popular because of the high infrastructure cost and environmental issues.Tidal lagoons which are very much similar to the barrages and cost less. Besides, they can be configured so that they can generate continuously.

To produce energy using tidal power, a tidal energy generator is used. Higher the height of the water levels or stronger the tidal current velocities, greater will be the tidal power generation.

Tidal movement causes the Earth-Moon system to loose energy continuously. This happens because of the water being pumped up around the coastlines due to the natural restrictions and because of the viscous dissipation in turbulence and at the sea bed.

Tidal energy is inexhaustible and can be regarded as a great renewable energy source.

Benefits of tidal power generation

Tidal power generation is not as famous as the other conventional methods of power generation like thermal power or hydroelectric power. But it does not imply that they are not useful. In future we will be dependent on tidal power, solar power and wind power for our energy consumptions. Amongst them, tidal power is going to play a strong role as tides are more predictable than the other sources. But to use tidal power to produce electricity is not that easy and is also very expensive. But with the progress of the science, we are sure to find a cheaper and more effective way to generate electricity using tidal power.

The benefits of the tidal power generation are as follows:

1. Resource:
The first most important benefit of the tidal power generation is that the resource which is required for its generation i.e. tidal water is available quite easily and is free of cost. Tidal water which is used to rotate the turbines is available during the tides and both high and low tide water are used for the purpose. The speed of rotation of the turbines depends on the height of the water level and the tidal current velocities. Greater height and stronger velocities helps in more tidal power generation. This helps the tidal power plant to save the expenses which are incurred by the other power plants like nuclear or thermal or hydroelectric for procuring radioactive materials or coals etc.

2. Renewable form of energy
Tidal energy is a renewable form of energy as it is inexhaustible because it is produced from the tides which are caused due to the relative motion of the Sun and the Earth and the Earth and the Moon.

3. Cost effective:
Tidal power plants can be maintained easily and that too without spending much. Moreover, the vertical axis turbines and the offshore turbines are not that much expensive to build.

4. Eco friendly
Tidal power plants are eco friendly. No greenhouse gases or other poisonous gases or other wastes are produced.

5. Tourism
Construction of structures like barrages, turbines and lagoons which are commonly not found becomes a craze for the general public. Hence, a tidal power plant can make a place popular. It can also help to encourage tourism in the neighboring areas. In this way, local people can be helped so that they can improve their economic condition.

Though, there are lots of advantages to tidal power generation there are disadvantages too. So to use the tidal power more effectively for the generation of electricity, it is necessary to overcome some of the major disadvantages. Moreover, care should be taken so that the marine environment does not get badly affected.

Is Hydropower Viable?

It is seen that the construction of power production stations of most of renewable sources of energy are quite costly. Hydro electric power station installations are also very costly.

For hydroelectric power, the initial costs of building are high and the period of construction of dams is long due to the time taken to relocate all the living things originally placed in the site. It also is quite difficult to channelize required amount of water into the dam. But, in the long run it is seen that the cost of production of power is quite cheap, hen calculated on an overall long term basis.

Once the basic structures are built the process becomes quite simple because, water is free and is also a renewable resource.

When compared to the cost of production of other power production is very low, it is almost half when compared to that of power production using coal. Also there are no techno- barriers in hydro power production, because all technologies are quite established.

When the construction of hydroelectric power plant is properly handled a lot of water can be conserved and used up for irrigation and other household uses. This makes the construction of dams multipurpose. It is used as a flood control mechanism also and a reservoir for the associated wetland flora and fauna.

For the multiplication of fishes a ladder system can be provided, thereby making the water stored restore the natural environment of the fishes and other organisms. Thus with one establishment cost many purposes can be solved, along with the conservation of the ecosystem.

The clean energy generated every year offers a valuable alternate for the very polluting and carbon and sulphur di oxide emitting other non renewable sources of energy, and reducing the amount of acid rains.

The viability of hydro electricity can be understood from the fact that more and more countries are increasing the production of electicity from water. 82% of power generated in the US is from hydroelectricity, Japan produces 84% of its energy from water followed by more than 80% in France and 73% in Germany. China, which primarily depends on its large coal deposits, has also started to turn its attention towards hydropower.

Generally the pay back period of hydropower is after 5-8 years, this period onwards the returns are very stable and the maintenance becomes simple. Having a power project in hilly terrains also reduces the cost of construction because, here we can use adjoining hills as a natural barrier for water and construct a structure to control the flow of water alone.

This kind of structure is helpful to restore the agricultural landscape of the area, it broadens the recreational quality and also makes the environment more healthy and picturesque.

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