Electrical Energy Audit of Electricity Bill and Few Tips Common for all industries MOHAN MENGHRAJANI

Electrical Energy Audit of Electricity Bill and Few Tips Common for all industries MOHAN MENGHRAJANI

Energy Audit of Electricity Bill Energy bill sent by a DISCOM should be read minutely. It gives idea: Whether all incentives are achieved/missed and reasons thereof. What is specific power consumption and departures from bench mark

A Sample Electricity Bill

Incentives & Penalties (Note: Tariff Details Referred here pertain to MSEDCL -Commercial circular 243 dated 3.7.2015) 1)Prompt payment incentive(within 7 days ) 2) P.F. incentive up to 7% (energy charges + FAC+ Demand charges but excluding taxes and duties) for maintaining P.F. unity There is also penalty for maintaining P.F. below 0.9 as described below:

P.F. Incentive in % P.F. Penalty in % 0.95 0 0.90 0 0.96 1 0.89 2 0.97 2 0.88 3 0.98 3 0.87 4 0.99 5 0.86 5 1.0 7 0.85 6 0.84 7 0.83 8 0.82 9 0.81 10

kvar capacity addition for improving P.F to maximum possible Formulae kvar (Capacitor capacity to be added) = Load in kw x (tan Ө1- tan Ө2) Where - Load in kw is the load recorded on energy meter for MD recording duration-30 minutes or 15 minutes interval, as applicable. Preferably this MD in kw may be the cycle which has recorded maximum MD. - tan Ө1 ( based on existing peak PF) and tan Ө2 on the improved PF - PF i.e. cos Ө1 is the peak PF, which is the ratio of MD in kw and kva. Therefore Ө1 can be found out from table and so also tan Ө1. Similarly, tan Ө2 can be found out from desired PF

Load Factor Incentive L.F. incentive starts from 76% load onwards and is maximum up to 15% of energy charges The incentive in table form is attached herewith. Please note that L.F. incentive will not be applicable if contract demand is exceeded

L.F. Incentive Load factor % Incentive % Load factor % Incentive % 76 0.75 89 11.5 77 1.5 90 12.5 78 2.25 92 13.5 79 3 93 14.5 80 3.75 93-100 15 81 4.5 82 5.25 83 6 84 6.75 85 7.5 86 8.5 87 9.5 88 10.5

Further Incentives No penalty for exceeding C.D. during 22.00 to 06.00 hrs Reduced energy charges during the period 22.00 to 06.00 hrs.(less Rs. 1.5/kWh) The pumping /draining job even fabrication job if possible and not associated with continuous processing should be done during this period

Meaning of Billing Demand For LT consumer Maximum of 1) 65% recorded during 06.00to 22.00 hrs 2) 40% of contract demand For HT consumer 1) Maximum of 1) actual MD recorded during 06.to 2200 2)75% of highest MD recorded during last 11 months 3) 50% of contract demand It is interesting to note that there is large difference in LT tariff for power looms between up to 20 kw and above 20kW and is discussed as under

Energy & Demand Charges for power looms Load up to 20 KW Load above 20 KW Energy charges Rs. 5.43/kWh Rs. 6.88/kWh Demand charges Rs. 220 per installation Rs. 150 /kva/month

Specific power consumption & Bench marking Specific power consumption = No. of Unit of production/ Energy bill units ( or total electricity consumption, including captive power generation). Unit of production will be different from industry to industry In some cases it can be number, in some cases it can be in kg/ton, litres, meters etc. Bench mark is the lowest energy consumed for the same production in the past under similar working conditions. More appropriate will be the figure obtainable from same reputed production manufacturers

How to reduce energy bill without affecting production In other words doing energy audit? 1. Know your M/C. Stitch in time to save nine 2. If possible Replace first and then Repair to reduce M/c down time 3. Arrest all types of leakages/wastages say water,air,gas,oil, heat,unused lights etc. 4. Check for proper functioning of motors compressors No noise, vibration, high temperature (All should be near to design values at the most within permissible limits). Negligence will add to power consumption. 5. Check whether right capacity of motor is used All motors etc should run above 70% capacity, of course not above 110%. unless it is designed

How to reduce energy bill without affecting production In other words doing energy audit? CONTD 6. The replacement programme should be chalked out for inefficient/ faulty motors. It will give return in near future. The management can be appraised giving the simple payback period (preferably not more than 3 years). Use VFD where high capacity motor which runs on partial load all the times, cannot be afforded to be replaced

How to reduce energy bill without affecting production In other words doing energy audit? CONTD 7. This concept also applies to transformers also for loading 8. Use wind ventilators instead of Exhaust fans wherever possible 9.Avoiding of breakdown by installing appropriate capacity of wires, cables, switch gears with reliable protection. 10.No loose contact both electrically and mechanically everywhere. They can cause havoc. 11.Install auto system wherever possible. Should be implemented asap viz: i) P.F. control Ii) Pump control using pressure/level/flow sensors Iii)Lighting,air conditioning control using occupation sensors, use of natural lights Iv)Load control. Switching on DG to monitor maximum demand.

How to reduce energy bill without affecting production In other words doing energy audit? CONTD 12. Safety first and observe everywhere by: i)cleanliness & tidiness. This will reduce accidents, improve transport of materials inside factory and add to production. Ii) Adequate illumination at working place Use LED at passages, warehouses parking etc. similar type iii)proper tools wires slings etc. Periodical checking/testing from authorised testing agencies iv) Personal protection equipment such as helmet /goggles/breathing mask etc v)perfect electrical earthing preferably below 1 ohm All metallic parts to be earthed secularly At the end I will emphasize on developing the ATTITUDE and DETERMINATION amongst self (Owner) & employees and goal will not be far away. M.N.Menghrajani Mob 9867317293 Certified Energy Auditor EA -4617

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