Generic end use energy efficiency options in electrical systems.
1. GENERIC END USE ENERGY EFFICIENCY OPTIONS IN ELECTRICAL SYSTEMS
D PAWAN KUMAR
2. Rescheduling loads/Staggering.
Storage of products/in process
material/process utilities like refrigeration
Shedding of non essential loads
Operation of captive /cogen power generation
Reactive power compensation
Adoption of MD control automation.
3. The generic areas for motor energy efficiency
improvement include:-
Ensuring rated voltage, frequency at input terminals.
Avoidance of oversized motors and part load inefficiencies
Optimum cable sizing and power factor improvement .
Choice of solid state low loss starters and motor controllers
Choice of state-of-the-art efficient variable speed system s
such as V/F controls
Good maintenance practices
Avoidance of idle operations, interlocking adoption
Avoidance of spurious bearings, consumables
Ensuring efficiency and quality assurance in case of
rewinding
Harmonics filtration for THD control.
Adoption of efficient gear couplings, belt drives
4. Generic energy efficiency improvement opportunities in refrigeration
plants include:-
Better upkeep and maintenance of all heat transfer surfaces, i.e., evaporator,
condenser and cooling tower
Avoidance of leakages/replenishment of refrigerant
Thermal insulation upkeep/up gradation
Avoidance of part load operations in compressor, chilled water pumps and cooling
water pumps
Maximizing operating evaporator temperature (compressor suction pressure)
while satisfying process temperature requirements
Minimizing condenser temperature (compressor discharge pressure) by improved
heat rejection in condenser circuit
Ensuring adequacy of chilled water, condenser water flows
Avoidance of idle operations
Avoidance of idle flows of chilled water through non-operational chillers
Adopting two stage or three stage absorption systems for steam economy
Adoption of eco-friendly VAR systems and non CFC, VCR systems in place
of CFC based VCR systems existing (VAR - Vapor Absorption
Refrigeration; VCR - Vapor Compressors Refrigeration)
5. The generic opportunities for pumping system energy efficiency improvement
include:-
Operation of the pump at a duty point close to the best efficiency point in
terms of head and flow. In other words, choice of right pump for given duty.
Minimum restrictions in suction path and providing maximum possible
suction head for pump.
Minimum restrictions in discharge path, especially throttling controls.
Good maintenance practices to avoid recirculation effects and proper
condition of impellers (wear-out, pitting, etc).
Ensuring good dynamic balancing of shaft and fit condition of bearings
Ensuring correct voltage supply.
Operating at minimum possible discharge pressure, with respect to end use
requirements.
Rationalizing the pipe size for optimum pressure drops
Minimizing losses in bends/valves
Good housekeeping practices
Replacement option by high efficiency pumps
Need based option of variable speed drives for efficient capacity control
6. The generic opportunities for energy efficiency improvement in
fans and fan systems include:-
Operation of fan at close to best efficiency duty point.
Minimum restrictions in suction path (no dampers)
Minimum restrictions in discharge path (no dampers)
Operation at rational head and flow, vis-à-vis process requirements.
Ensuring correct voltage and frequency at supply
Good maintenance practices
Good housekeeping practices
Minimizing in leak air / gas
Minimizing out leak air / gas
Rationalizing duct size for minimizing pressure drops
Minimizing sharp bends
Replacement options by higher efficiency fans
Need based option of variable speed drives if capacity control is
required for end use
Minimizing slippage losses in belts
7. Generic energy efficiency opportunities in
air compressors and system include;-
Use of compressed air at optimum pressure,
minimization of line pressure drops
Avoiding unload operations
Good practices in maintenance and housekeeping
Leakage avoidance.
Replacement by high efficiency compressors
Suction air cooling
Improving heat transfer in inter and after coolers
Replacing pneumatic tools by electric tools to save
on conversion efficiency
Adopting energy efficient drying systems, air
ambiators, filters, nozzles.
8. The generic energy audit and efficiency
improvement opportunities in industrial lighting
include:
Choice of most energy efficient lighting devices
Right positioning of the lighting devices
Use of lights only when needed
Use of energy efficient starters
Application of appropriate controllers
Good housekeeping / maintenance practices (cleanliness of
surfaces)
Ensuring correct voltage and frequency of input supply