INTRODUCTION:

As the earth’s population increases and becomes more modernized, it has

become evident that supplying energy to everyone is a daunting task.

Furthermore, the resources used to supply this energy, generally fossil fuels,

do not regenerate at a rate to consider them renewable. The United States

gets approximately 93% of its energy from nonrenewable sources. These

sources include uranium ore (nuclear), coal, natural gas, and oil (U.S.

Energy Information Administration). As we drain the supplies of earth’s

resources, we must figure out a way to create energy using renewable

sources.

Renewable energy is generally defined as energy that comes from resources

which are naturally replenished on a human timescale such as sunlight,

wind, rain, tides, waves and geothermal heat as the International Energy

Agency explains. Renewable energy replaces conventional fuels in four

distinct areas: electricity generation, hot water/space heating, motor fuels,

and rural (off-grid) energy services.

Renewable energy is derived from natural processes that are replenished

constantly. In its various forms, it derives directly from the sun, or from heat

generated deep within the earth Included in the definition is electricity and

heat generated from solar, wind, ocean, hydropower, biomass, geothermal

resources, and bio fuels and hydrogen derived from renewable resources.

Renewable Tidal energy:

Comparatively to other renewable energy system, Tidal energy gives more

efficiency, so we are going for renewable tidal energy process through CFD.

Energy in water 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. The largest of which is the Three Gorges Dam in China

and a smaller example is 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).Run-of-the-river hydroelectricity systems derive

kinetic energy from rivers and oceans without the creation of a large

reservoir. Hydropower is produced in 150 countries, with the Asia-Pacific

region generating 32 percent of global hydropower in 2010. China is the

largest hydroelectricity producer, with 721 terawatt-hours of production in

2010, representing around 17 percent of domestic electricity use. There are

now three hydroelectricity plants larger than 10 GW: the Three Gorges Dam

in China, Itaipu Dam across the Brazil/Paraguay border, and Guri Dam in

Venezuela.

Unlike other forms of hydropower technologies, such as turbines and water

mills, the device, called the VIVACE (vortex induced vibration for aquatic

clean energy) converter, can generate electricity from slow moving water,

and typically found in ocean and river currents. The device is thought to be

the first that can harness energy from flows moving slower than 2 knots

(about 3.7 km per hour). Most currents are slower than 3 knots. Turbines and

water mills need an average of 5 to 7 knots to operate efficiently. In

addition, the device can operate in water surges, allowing it to take

advantage of faster flows.

The VIVACE converter exploits the turbulent effects of vortices (swirling

currents) that form around an obstacle in flowing water. It was partly

inspired by the way fish swim. Fish propel themselves forward by

generating vortices or by taking advantage of naturally occurring vortices in

the turbulent trail of other fish.

The device consists of a cylinder which is placed below the surface of the

water, across the direction of current flow. As water flows past the device, it

is disturbed and creates vortices which cause oscillations, or vibrations,

inside the cylinder. Mechanical energy from these oscillations can be

efficiently converted into electrical energy via a generator.