Alternative energy

ALTERNATIVE RESOURCES OF ENERGY

CONTENTS: SOLAR ENERGY

WIND ENERGY

TIDAL ENERGY

BIOMASS ENERGY

GEOTHERMAL ENERGY

SOLAR ENERGY

The Earth receives 174 petawatts(PW) of incoming solar radiation at the upper atmosphere. Approximately 34% is reflected back to space while the rest is absorbed by clouds, oceans and land masses.

By photosynthesis green plants convert solar energy into chemical energy, which produces food, wood and the biomass from which fossil fuels are derived.

USAGE OF SOLAR POWER

Agricultural Usage:

Greenhouses convert solar light to heat, enabling year-round production and the growth of specialty crops and other plants not naturally suited to the local climate.

Agriculture seeks to optimize the capture of solar energy in order to optimize the productivity of plants. Sunlight is generally considered a plentiful resource, the exceptions highlight the importance of solar energy to agriculture.

Water Heating:

Solar hot water systems use sunlight to heat water. In low geographical latitudes from 60 to 70% of the domestic hot water use with temperatures up to 60C can be provided by solar heating systems. The most common types of solar water heaters are evacuated tube collectors (44%) and glazed flat plate collectors (34%) generally used for domestic hot water.

Solar Cooking:

Basic cooker cooks at temperature within 90-150C, whereas reflector cookers cook at 315C.The picture attached is of Solar Bowl in Auroville,India in which it cooks.

Experimental Solar Power:

A solar pond is a pool of salt water that collects and stores solar energy. This solar pond was capable of producing temperatures of 90C in its bottom layer and had an estimated solar-to-electric efficiency of 2%.

Thermo generators convert temperature difference between unlike metals into electric current and are used in deep space missions.

Solar cookers use sunlight for cooking, drying and pasteurization. They can be grouped into three broad categories: box cookers, panel cookers and reflector cookers.

Solar Vehicle:

Vehicles use solar panels for auxiliary power. The world wide solar car race challenges give us a clear reflection of this. Not only cars are even solar boats are found on the Pacific & Atlantic. Solar power enriching vehicles have reached the sky also.

This vehicles are powered by photovoltaic.

Receivers:

We can say that solar energy is the main source of all other renewable and non renewable sources of energy found on earth.

These pictures are the most frequently used as solar energy receivers.

WIND ENERGY

Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, wind mills for mechanical power, wind pumps for pumping water or drainage, or sails to propel ships.

Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmosphere.

Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160km/h (99mph) occur.

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USAGE OF WIND ENERGYWINDMILL:

Windmills are typically installed in favorable windy locations. The higher wind speed, much of the energy comes in short bursts.

In a wind farm, individual turbines are interconnected with a medium voltage (34.5 kV), power collection system and communications network. At a substation, this medium-voltage electrical current is increased in voltage with a transformer for connection to the high voltage electric power transmission system.

The main component of a windmill is Wind turbine. It consist of gearbox, rotor shaft and brake assembly.

The modern windmills are designed unlike conventional windmills. They occupy less space and the durability is much more high in environmental change. This reserve capacity on a system equal in MW to 20% of added wind could be retired when such wind is added without affecting system security or robustness. But the precise value is irrelevant since the main value of wind is its fuel and CO2 savings.

By 2010, the World Wind Energy Association expects 160GW of capacity to be installed worldwide, up from 73.9GW at the end of 2006, implying an anticipated net growth rate of more than 21% per year.

FURTHER PROGRESS:

TIDAL ENERGY

Tidal power, sometimes also called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power.

Tidal energy is generated by the relative motion of the water which interact via gravitational forces. Periodic changes of water levels, and associated tidal currents, are due to the gravitational attraction by the Sun and Moon.

USAGE OF TIDAL ENERGYThe stronger the tide, either in water level height or tidal current velocities, the greater the potential for tidal energy generation.

Modern advances in turbine technology may eventually see large amounts of power generated from the ocean, especially tidal currents using the tidal stream designs but also from the major thermal current systems such as Axial turbines

Tidal stream systems make use of the kinetic energy of moving water to power turbines. Barrages make use of the potential energy in the difference in height between high and low tides.

It is estimated that up to 3GW could be extracted by Barrage tidal power . This would not only supply the island's needs but also leave a considerable surplus for export.

A large 240 MW Barrage tidal power has been developed in Russia.

The problem of that kind of tidal power is the generation of flood that effects the surroundings of the barrage locality.A tidal power scheme is a long-term source of electricity. It has been projected to save 18 million tones of coal per year of operation. This decreases the output of greenhouse gases into the atmosphere.

BIOMASS ENERGY

Biomass, a renewable energy source, is biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels.

Forest residues, yard clippings and wood chips and garbage may be used as biomass. Biomass also includes plant or animal matter used for production of fibers or chemicals.

Biomass energy is derived from three distinct energy sources like wood, waste, alcohol fuels, crops and landfill gasses. They are used in various ways-

Bioproduct Biomass Fuelled Power Plants Biomass gasification Bioenergy Wood fuel

Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel. Methane gas is the main ingredient of natural gas.

USAGE OF BIOMASS POWER

Biomass is carbon based and is composed of a mixture of organic molecules.

The largest source of energy from wood is pulping liquor, a waste product from processes of the pulp, paper and paperboard industry.

Municipal Solid Waste (MSW), manufacturing waste are also sources.

Biomass alcohol fuel, or ethanol, is derived almost exclusively from corn.

Crops like corn and sugar cane can be fermented to produce the transportation fuel, ethanol.

Smelly stuff, like rotting garbage, and agricultural and human waste, release methane gas.

GEOTHERMAL ENERGY

Geothermal power is cost effective, reliable, sustainable, and environmentally friendly. This parasitic load is normally a fraction of the heat output, so it is always less polluting than electric heating.

Geothermal energy is the heat from the Earth.

Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.

USAGE OF GEOTHERMAL ENERGY Generating electricity from the earth's heat. Producing heat directly from hot water within the earth. Using the shallow ground to heat and cool buildings.

Processes:

Geothermal has minimal land and freshwater requirements but no fuel, and is therefore immune to fuel cost fluctuations. But capital costs tend to be high.

Worldwide, geothermal plants have the capacity to generate about 10 gigawatts of electricity as of 2007.