Showing posts with label davidson hill venturi turbine. Show all posts
Showing posts with label davidson hill venturi turbine. Show all posts

Saturday, December 13, 2014

Era of Renewable Energy

Over the last 1 year I have made many posts on my blog regarding renewable and alternative sources of energy. After looking at all the options available I have come to a conclusion that International crude oil prices may come down further in the coming days. The major reason for this is we have come to a time when we have found ways to generate electricity without burning fossil fuel , without causing any pollution. Without generating more greenhouse gases thereby preventing global warming.

The global oil prices went as high as $140 and it was predicted then that oil prices would go as high as $ 200. This gave a great fillip to renewable energy research. Research on solar energy which was going on for decades have come to point where it has matched conventional energy in terms of price. Germany is one of the biggest consumers of solar energy now. Although Germany gets lesser sunlight as compared to many Asian and African nations.

New technologies for for harnessing wind power and tidal power has come into existence. New design of Windmills like Invelox - in which the direction of the wind flow does not matter anymore and the wind is channeled and concentrated. Which enables the generation of electricity even if the wind speed is very low. In fact the cut-in speed( the speed at which the system starts generating electricity) is as low as 2 miles per hour in other words a little less than 1 m/sec. Which makes it possible to be installed anywhere to generate electricity. The manufactures are claiming that INVELOX can produce electricity for as low as 2 cents per kilowatt hour. Also using kites to generate electricity.

Different Kinds of Tidal energy harnessing technologies are coming to existence viz Davidson Venturi Hill Turbine, Searaser, Minesto underwater kites. The tides are caused in the seas and oceans due to the gravitational fields of the earth and moon. The great thing about ocean tides is that they are highly predictable. Nowhere in the world you see an ocean or a sea that is quiet. While the Davidson Venturi Hill Turbine maximised energy output by using the Venturi effect, Searaser utilized the up and down motion of the sea waves to move a buoyant piston to pump water to a reservoir that is located at some height and then make the collected water fall with the help of gravity , this running water would move a turbine that would generate electricity.


Davidson Venturi Hill turbine



SEARASER





The Minesto underwater kites tapped into the low water speeds to generate substantial amounts of electricity, the motion of the kite is controlled by rudder by an operator. The benefit of ocean waves over atmospheric wind is that water is 800 times denser than air and being 800 times denser it contains 800 time more energy. The Minesto underwater kites has different models the largest 14 meter one generates electricity of 850 kilowatts at water speed of mere 1.73 m/sec.


Minesto underwater kites

Offshore Wind Energy farms exist all over the world. Denmark has lots of them. The condition of having an offshore wind farm in the sea is that the water should be shallow since the tower will have its base at the sea bed and hence there is a limit to the length of the tower. As we go farther into the ocean it gets deeper and deeper. But far off the cost the wind speeds are constant and very good. But setting up an offshore wind tower (the tower will have its base at the seabed) is not possible since the sea is too deep. This problem is solved now and engineers have come with Floating Offshore Wind towers. This towers since they are floating in the ocean can be set up anywhere.


Floating offshore wind turbine


The little higher costs will be offset by the better quality of winds. The major part of earth's surface is water (70%). So a country that has a large coast can generate as much electricity as it wants using this technology even in deep sea. The future of this technology may be very bright since in the future we may have electric ships that would get its energy from such plants that would be located at certain intervals along its path.

Thus now we have come to a point where we can get almost all our energy needs from renewable sources of energy and thus we can minimize the utilization of fossil fuels for energy requirements. No matter how low the prices of crude oil becomes the focus on utilization green and renewable sources of energy should not go away. 

Friday, April 18, 2014

Tidal Energy with Davidson Hill Venturi turbine.

A great source of energy largely untapped is is the energy from the ocean currents it is also called Tidal Energy. The tides in oceans are caused by the gravitational effects of the sun and moon. Tides follow a pattern and can be predicted years in advance unlike wind. Water is 832 times denser than air so a relatively small turbine can produce large amounts of electricity as compared to Wind Turbines. 




This is the diagram of the davidson hill venturi turbine , it makes use of the Venturi effect the flow of ocean current is in the smaller side of the turbine so at the other end where the area of the crossection is larger there  velocity of flow of water is reduced thus creating a low pressure area which leads to more current rushing towards that side via the turbine thus making the turbine rotate a very high amount of efficiency is achievable through the Davidson Hill Venturi turbine ,This video of Davidson Hill Turbine will explain more .




Tidal energy is a largely untapped but a very promising source of energy , and it would have very low maintenance costs. This link would shows that a DHV turbine with a 10 meter rotor will produce a few megwatts of electricity at moderate water speeds. 

      Fossil fuel and coal are  getting scarse and of course their combusiton leads to realese of green house gases which are resulting in global warming tapping into renewable sources of energy like tidal energy can produce many terawatts of energy without producing any pollution no loss of limited natural resource. 
We can do away with coal and gas based power plants at least in areas of earth that are within a distance of 1000 kms from the ocean.

       Talking in context of India we have one of the longest coastlines in the world, the power of the sea currents across Arabian Sea, Indian ocean and Bay of Bengal can be tapped into and power can be generated for entire south, east and western parts of India.