Reduced cost tidal and / or water flow power generator

Abstract

A power generator comprising at least one rotatable cylinder 1 mechanically coupled to an electricity generator 3. The cylinder 1 is located on a bed of a tidal flow zone 2, such that water flowing ov

Description

This invention relates to a tidal and / or water flow power generator which harnesses and converts tidal flows into electricity for a reduced cost. 21 06 23 Tidal flows can provide an extra source of renewable energy at predicted times of the day, however, although water is 1,000 times denser than air the velocity of the flow is low’. The depth is also quite low, thus in stream turbines can only generate a relatively small amount of power each while undergoing powerful and corrosive saltwater flows which results in shorter lifespans. To overcome this, the present invention proposes a tidal and / or 'water flow power generator comprising at least one rotatable cylinder, wherein said at least one rotatable cylinder is located on a sea and / or river and / or tidal flow bed, wherein said at least one rotatable cylinder is mechanically coupled to an electrical generator w’herein water flows over said at least one rotatable cylinder causing it to rotate wherein said rotation of said at least one rotatable cylinder drives said electrical generator wherein a hydro-dynamically shaped ramp guides the water flow onto an upper surface of said at least one rotatable cylinder. When the tidal and / or water flow flows over the cylinder friction from the passing water causes it to rotate, and with very long or multiple cylinders energy from a large flowing area can be concentrated onto the electrical generator which reduces the cost of having multiple generators. Due to the more passive interaction of the water with the cylinder there isn’t a turbine for the water to "whack" into and damage resulting in much longer lifespans which also further reduces costs. The cylinder will also rotate equally efficient whichever direction the flow passes, upstream or downstream, inland or outbound with the tides. Preferably, there are two or more cylinders. Preferably, a hydro-dynamically shaped ramp guides said water flow onto an upper surface of said cylinder / s. Preferably, said cylinder / s have a rough and / or grooved surface to provide friction for said water. Preferably, said cylinder / s are hollow. Preferably, said cylinder / s are composed of plastic. Preferably, said cylinder / s are composed of a corrosion resistant marine grade metal. Preferably, said electrical generator is raised above said water on a platform and / or tower and / or structure means. Preferably, said electrical generator is positioned on dry land. Preferably, mechanical coupling of said cylinders and said electrical generator is by chain and sprocket means and / or belt and pulley means and / or gear means . An example of the invention will now be described by referring to the accompanying drawings : - figures 1 and 3 show a side view of reduced cost tidal and / or water flow power generator and; - figure 2 shows a top view of reduced cost tidal and / or generator according to the invention. water flow power 21 06 23 At least one rotatable cylinder 1 is positioned on a sea or river or tidal flow bed 2 and is mechanically coupled to an electrical generator 3, the rotatable cylinder rotates when water 4 flows over it which turns the generator to generate electricity. There may be two or more cylinders, there may be a hydro-dynamically shaped ramp 5 to guide water onto the upper surface of the cylinders, the cylinders may have a rough or grooved surface, the cylinders may be hollow, the cylinders may be composed of plastic, the cylinders may be composed of a corrosion resistant marine grade metal, the electrical generator may be positioned above the water on a platform and / or tower and / or structure means, the electrical generator may be positioned on dry land and the coupling of the cylinders to the electrical generator may be by chain and sprocket means or belt and pulley means or gear means 6. When water flows over the cylinders they rotate easily concentrating energy along their length to the generator, the force on the cylinders at any one point is only subtle enabling them to have a long lifespan. A single cylinder over a substantial length could be used to generate power, or multiple short, medium or long cylinders can be arranged to produce as much power as is required. This enables simple construction techniques, merely arranging existing cylinders bought off-the-shelf keeps costs low and build times quick. The whole structure of the generator can be tethered to the sea bed by stakes or tether means, and the hydro-dynamically shaped (as in aerodynamically shaped) ramp can be made of suitable concrete which can help to provide tethering for the cylinders or it could be made of metal in a hollow form. If any debris were to drift near to the cylinders, the down pull of one cylinder is met with the up pull of the next cylinder which pushes the debris back up, which reduces the chances of anything jamming. The power of all of the cylinders combined also helps to release any jams as they happen. Wildlife such as fish should also be ejected away from the cylinders without harm if they swim too near, with much less risk than a turbine. With the electrical generator being out of the water, corrosive water and the electrics are separated and maintenance is quick and easy. With the cylinders underwater this makes the device storm resistant and robust. Figure 3 shows that the cylinders could be arranged on a floating tethered barge with the water flow on the underside rotating them, sealed plastic cylinders could form part of the buoyancy, however, this would cause difficulties in storms and may preclude the use of an on-shore generator, but in some circumstances this could be a useful option, such as where there is unstable or uneven ground / sea or river bed. As a floating device it would be easily movable for maintenance or for sheltering during storms. Tethering options could be by cables attached between the barge and the sea bed 7. 21 06 23

Claims

1 A tidal and / or water flow power generator comprising at least one rotatable cylinder, wherein said at least one rotatable cylinder is located on a sea and / or river and / or tidal flow bed, wherein said at least one rotatable cylinder is mechanically coupled to an electrical generator wherein water flows over said at least one rotatable cylinder causing it to rotate wherein said rotation of said at least one rotatable cylinder drives said electrical generator wherein a hydro-dynamically shaped ramp guides the 'water flow7 onto an upper surface of said at least one rotatable cylinder.2 A tidal and / or water flow power generator according to claim 1, wherein there are two or more cylinders.3 A tidal and / or water flow power generator according to any preceding claim, wherein said cylinder / s have a rough and / or grooved surface to provide friction for said water.21 06 234 A tidal and / or water flow power generator according to any preceding claim, wherein said cylinder / s are hollow.5 A tidal and / or water flow power generator according to any preceding claim, wherein said cylinder / s are composed of plastic.6 A tidal and / or water flow power generator according to any of claims 1-4, wherein said cylinder / s are composed of a corrosion resistant marine grade metal.7 A tidal and / or water flow power generator according to any preceding claim, wherein said electrical generator is raised above said water on a platform and / or tower and / or structure means.8 A tidal and / or 'water flow power generator according to any preceding claim, wherein said electrical generator is positioned on dry land.9 A tidal and / or water flow pow’er generator according to any preceding claim, wherein mechanical coupling of said cylinders and said electrical generator is by chain and sprocket means and / or belt and pulley means and / or gear means .

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