2. WHY ENERGY MANAGEMENT ? Generation of power needs resources Resources available on earth are of Diminishing Nature capital investment requirement is very high for renewable energy sources Hence, to restrict the use or increase the life of diminishing type of resources.
3. Thus the need to conserve energy, particularly in industry and commerce is strongly felt as the energy cost takes up substantial share in the overall cost structure of the operation. Hence it calls MANAGEMENT OF ENERGY
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5. Plantation Sector… Global energy Crisis Carbon conservation Sequestration in plantation Increasing cost of production Facing Energy shortage Cost optimization
6. Strategies for Conservation Management for conservation (prevent emission) Management for storage (short term measure) Management for substitution (long term)
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8. Thermal energy is required to remove the moisture from the green leaf as well as fermented tea, whereas electrical energy is required at almost all stages of unit operations.
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10. CONTD…….. 2) Waste Heat Recovery :- The waste heat available in tea factories are mainly from (i) flue gas and (ii) exhaust of tea dryer. Sensible heat losses in the flue gases leaving the chimney is 35-55% of the heat input to the furnace, which can be recovered by either preheating combustion air or charge preheating. Preheating combustion air effects fuel savings. Heating devices used for this purpose are recuperator and regenerator.
11. CONTD…….. 3)Electrical Energy Conservation :- Motors of adequate capacity should replace oversized motors. This will reduce the under-utilisation of motor capacity. Power factor improvement is to be investigated. Power factor may be corrected to at least 90% under rated loaded condition. Energy efficient motors and Soft start motors enable to reduce electrical energy losses. For lightly loaded motors, delta-to-star conversion connection schemes can be used.
12. Proposed Energy Saving Equipments: Fluidised Bed Dryer with Biomass Gasifier:- The Fluidised Bed Dryer can be supplied with hot air produced by the heater based on woody biomass down draught gasifier. The system, specially adapted for tea drying, uses conventional fired wood or any other. The system, specially adapted for tea drying, uses conventional fired wood or any other woody biomass with density above 250 kg/m3 available at the factory location. The gasifiers have achieved upto 80% thermal efficiency in the conversion of solid biomass to gas and upto 33% of efficiency in electrical conversion.
13. CONTD…….. 2) Combination Tea Dryer:- For producing tea with brisk, strong liquors, Endless Chain Pressure / Fluidised Bed Dryer combination dryers can be used in which low temperature firing and gradual removal of moisture take place. Its energy requirement is 3.6 kWh/kg of made tea. It has got water evaporation capacity of 700 kWh whereas the conventional dryers have a capacity of only 380-kg/hr. Fluidised Bed Dryer reduces the moisture of CTC dhool from 70% to 3% within 15 minutes whereas a conventional dryer takes 23 minutes.
14. CONTD…… 3) Heat Pump:- The exhaust gases from a tea dryer may have high moisture content. Since they are vented at a moderately high temperature to atmosphere, heat loss takes place. This heat can be recovered effectively by using a heat pump with a recycle system. The heat pump extracts heat from the vent gases by cooling them and uses it for heating the air going to the dryer. For a dryer of capacity 200 kg tea/hour in 2 shifts, approximate net investment required for heat pump system is Rs. 4.62 lakhs and payback period is less than 2 years.5
15. Alternate Energy Sources for Tea Industry: Combined Heat and Power System :- Combined heat and power (cogeneration) system is the coincident generation of necessary heat and power - electrical and/or mechanical - or the recovery of low level heat for power production. Two basic types of Combined Heat and Power systems are (i) bottoming cycle in which thermal energy is produced first and (ii) topping cycle in which electrical energy is produced first. For a tea factory, a steam turbine topping cycle is recommended5. Thermal match cogeneration system offers higher overall efficiency in tea manufacture. For the Combined Heat and Power system of the above capacity, approximate cost of the equipment is Rs. 1 crore and the payback period is around 6 years
16. CONTD…… 2) Solar Hot Air System :- On a clear sunny day, the saving on the fuel by use of solar energy is around 50% of the fuelwood used for drying. Solar air heating panels can be mounted on the roof of the tea factory. Ambient air drawn through the solar panels will get heated during daytime. One module of 10 m2 area can provide heat to the order of 2.1 MJ/year. Approximate cost of the modular solar hot air system is Rs. 8.5 lakhs and the payback period is around 4 years. The constraints in making use of solar panels in tea factories are difficulty in storage of heat, high initial cost and large area required for locating the solar collectors.
17. CONTD…… 3) Mini-Hydro Power Generation:- Waterpower is economical as well as non-polluting the environment. Depending on the head of water available, mini hydro can produce 100 - 500 kW. South Indian tea plantations have good potential for mini hydel schemes as they are located in hilly regions with mountainous terrains. Also streams and ravines are available to provide water sources . For a mini-hydel project, approximate cost per kW generation is Rs. 25,000 per kW. For 500 kW project, payback period is around 11 years.5
18. CONTD….. 4) Wind Power :- Wind energy has enormous resource potential in our country. In wind power plants, there is no fuel expenses as wind is free. The wind energy is environment friendly and pollution-free. The capacity can vary in the range 0.25-15 MW. Windmills have a life span of about 20 years. Once the plant starts generating power, the investment is paid back over a period of 7 years . Cost of power generation by wind reduces from Rs. 1.09/kWh in the first year to Rs. 0.23/kWh in the 8th year