NON-CONVENTIONAL SOURCES OF ENERGY ASHIR.A LECTURER DEPARTMENT OF CHEMICAL ENGINEERING

Alternative energy sources: Solar energy Wind energy Sea – Wave – Tide – Ocean thermal energy Geothermal energy Biomass

SOLAR ENERGY The ultimate source of energy is sun. Its potential is 178 billion mega watt, which is about 20,000 times world demand. Clean source of energy compared to other sources of energy. It is expected that it will be one of the most important supplies of energy in coming years.

Total world power demand = watts

If we can use 5% of the total energy, it will be 50 times what the world will require. Solar energy is trapped by producing steam and electricity by using PV panels. Solar energy is diluted form of energy. Only available on day time. Storage is required for ensuring continues supply of energy.

Storage Thermal storage Mechanical storage Chemical storage Usual method of storing energy Can be stored by producing hydrogen Using mechanical or electrical devices In chemical bonds or phase changing salts

APPLICATIONS OF SOLAR ENERGY Heating and cooling of residential building. Solar water heating. Solar drying of agricultural and animal products. Solar distillation on a small community scale. Salt production by evaporation of seawater. Solar cookers. Solar engines for water pumping.

Food refrigeration. Vapour absorption refrigeration systems. Concentrated energy is supplied to heat engine, which then drives compressor. Bio conversion and wind energy, which are indirect source of solar energy. Solar furnaces. Solar electric power generation Solar ponds Steam generators heated by rotating reflectors Reflectors with lenses and popes for fluid circulation. Solar photovoltaic cells for direct conversion of solar energy to electricity.

WIND ENERGY Winds are caused from two main factors. 1.Heating or cooling of the atmosphere which generates convection currents. Heating is caused by the absorption of solar energy on the earth’s surface and in the atmosphere. 2.The rotation of the earth with respect to atmosphere, and its motion around the sun.

Wind energy can be economically used for the generation of electrical energy. The energy available in the winds over the earth’s surface is estimated to be 1.6 x 10 7 MW. Wind energy can be utilized to run wind mill. – Which in turns drive generator to produce electricity. – The mechanical power can be used for pumping water.

Types of wind mills Horizontal axis Eg: multi blade type wind mill Sail type wind mill Propeller type wind mill Vertical axis Eg: Savonius type wind mill Darrieus type wind mill

Characteristics of wind energy: Renewable source of energy Non polluting Avoid fuel provision and transport Small scale production of electricity using wind is less costly For large scale production, lower cost can be achieved by mass production

Problems: Wind energy in available in dilute form. So conversion mechanism have to be necessarily large. Fluctuating in nature. Wind energy need storage means because of its irregularity. Wind energy systems are noisy. A large units can be heard many kilometers away. Large areas are needed to install wind farms for electrical power generation.

In India wind speed lies between 5km/hr to 20km/hr. India has a potential of 20,000MW of wind power. DNES plans to harvest 400MW of wind energy during eighth plan period. The low velocity and seasonal winds imply a high cost of exploitation of wind energy. Mainly used for water pumping and rural electrification.

MAJOR WIND MILL PROJECTS IN INDIA: CAZRI wind mill at Jodhpur (Rajasthan) WP-2 water pumping wind mill by NAL Bangalore. MP-1 sail wind mill at NAL Bangalore. Wind mills at Central Salt and Marine Chemicals Research Institute Bhavnagar. 12 PU 500 wind mill at NAL Bangalore. Madurai wind mill at Madurai (Tamil Nadu) Tayabji wind mill at Tilonia near Ajmer (Rajasthan) Sholapur wind mill at Sholapur

ENERGY FORM BIO-MASS AND BIO-GAS Bio-mass means organic matter. The potential application of bio-mass as an energy source is high in India. Bio-mass is produced in nature through photosynthesis achieved by solar energy conversion.

Photosynthesis reaction H 2 O + CO 2 + solar energy CH 2 O + O 2 CH 2 O is stable at low temperature. At high temperature it breaks and release 112kcal/mole. CH 2 O + O 2 H 2 O + CO 2 + solar energy + 112kcal/mole

Bio-mass resources fall into three categories: 1.Bio-mass in its traditional solid mass. eg: wood and agricultural residue. 2.Bio-mass in non-traditional form (converted into liquid fuels). eg: converting bio-mass into methanol or ethanol. 3. Production of biogas from bio-mass. – Bio-gas – % methane, % CO 2 and rest impurities.

Composition of Bio-mass: i.Concentrated waste – Municipal solids – Sewage wood products – Industrial waste – Manure of large lots ii.Dispersed waste residue – Crop residue – Disposed manure iii. Harvested bio-mass, bio-mass energy plantations

ENERGY PLANTATIONS: Selected species of trees would be planted and harvested over regular time period, on land, near the power plant. A large area is required for it. Tree which are suggested for use in India are eucalyptus, casuarina and babool.

BIO-GAS: Considered as a clean source of energy. Main source for bio-gas production is wet cow dung and livestock waste. Because of large cattle population in India, bio-gas is significant energy source. Other sources of bio-gas: Sewage Crop residue Vegetable waste Water hyacinth Poultry droppings Pig-manures Algae

In big cities, sewage source is the main source for production of bio-gas. The sewage bio-gas is found to contain 84% methane, which is a high quality fuel. In rural areas bio-mass found application in – Cooking – Lighting – Mechanical power – Generation of small electricity More than 7.3 lakh family based on bio-gas plants were installed during seventh period.