Tuesday, August 28, 2012

Inflated Electricity Bill....Why?

REASON FOR FAST RUNNING OF ELECTRIC METERS
- Why bills of electric consumption suddenly increased when electromechanical meters replaced with electronic meters?

SUDHIR KUMAR SRIVASTAV
AGM-RAPDRP
NTPC LIMITED, NEW DELHI

Abstract -This paper gives an insight into the various aspects on inflated billing of electric consumption for single phase consumers whose electromechanical meters are replaced with electronic meters. This may be very useful for all single phase consumers whose electricity bills are seems to be higher than actual consumption.

I           INTRODUCTION
Power Distribution utilities in India is facing a lot of challenges like theft of energy, improper billing, outdated technologies, poor maintenance, financial constraints etc leading to very poor financial health of the sector.
Distribution utilities have acted promptly on theft of energy & improper billing, through replacement of electromechanical meters with electronic meters. Main reasons for replacement of electromechanical meters with electronic meters are:
1.    Electromechanical meters, which were installed a few years ago, had started running slow due to moving components in the meter getting worn out.
2.    The electromechanical meters, with the passage of time and also by virtue of their design, did not record energy if load is very small.
3.    No measuring element was used in return circuit i.e. neutral wire in electromechanical meters. Tampering was easily possible in such meters e.g. reverse phase running, etc. (Detail described below with Figure-1 & Figure-2)

II          SALIENT FEATURES OF Electronic meters:      
1.    Small energy consumption by virtue of indicating lights, LEDs on switch boards, leakage of current due to old house wiring etc., gets recorded by highly sensitive and more accurate electronic meters.
2.    Some equipments e.g. TVs, DVDs, etc. when switched off through remote controls continue to consume energy unless they are switched off from the switch mounted on the equipment itself. These types of consumed energy are also recorded with electronic meters.
3.    Electronic meters are accurate and sensitive without any moving part. So sluggishness of meters were ruled out & new meters have started recording the actual energy consumption
4.    As no measuring element was used in return circuit i.e. neutral wire in electromechanical meters, tampering was easily possible in such meters e.g. reverse phase running, etc. In a tampered meter, it is possible to run the meter as and when required with simple operation of a toggle switch. To deal with tampering problems, a need was felt to have a meter, which has measuring element in neutral circuit also. So important additional design features have been incorporated in the present electronic meters i.e. measurement of current in neutral/return circuit in additional to phase circuit & measurement of higher of the two currents (one measured by measuring element in phase circuit and other by measuring element in neutral circuit.) for computation of energy consumption.

III         CAUSE OF INFLATED BILLING:
Feature of electronic meters as mentioned at point 1,2 & 3 above are providing more accurate. It is true that because of above reason there would be marginal increase in the electricity bills generated by new electronic meters as compared with old electromechanical meters. There is a feeling that the bills are inflated but it is only psychological.
But the feature of electronic meters as mentioned at point no.4 are a matter of concern and energy consumption recorded by electronic meter may be highly inflated, if neutral circuit of the household in not isolated properly.
Typical circuit of electromechanical meter is as below:


Here measuring element is used in phase circuit only. So tempering is easily possible by reversing the phase circuit as mentioned in Figure-2. If phase supply is connected to neutral of meter, neutral of meter is connected to load & other point of load is earthed,  proper voltage will applied across load & all electrical apparatus will be powered on, but consumption will be NIL, as current is not flowing through measuring coil.
So, to overcome this deficiency & to enable the utilities to trap the fraudulent consumers and to raise more accurate bills for the energy consumed by its consumers, the following important additional design features have been incorporated in the present electronic meters:
a)    Measurement of current in neutral/return circuit in additional to phase circuit.
b)    Measurement of higher of the two currents (one measured by measuring element in phase circuit and other by measuring element in neutral circuit.)
In electronic meter, if neutral circuit of any house is mixed/connected with any other house, there is possibility of highly inflated bill as described below:

Suppose you are HOUSE-2 & your all connection are perfectly alright, but your neutral is connected with neutral of HOUSE-1 and HOUSE-1 has disconnected his neutral with neutral of his meter.
As seen above, if neutral circuit of HOUSE-1 is disconnected with neutral of his meters and the same is connected with neutral of HOUSE-2, following will be the computation of energy in both houses:
FOR HOUSE-1:
Current through phase measuring coil           =          I2
Current through neutral measuring coil          =          0
Highest of the two current                              =          I2
So computation of energy (I^2*r*t) for HOUSE-2 will be OK.

FOR HOUSE-2 (Your House):
Current through phase measuring coil           =          I1
Current through neutral measuring coil          =          I1+I2
Highest of the two current                              =          I1+I2
So computation of energy for your house will be highly inflated.


There is one more possibility of inflated bill is due to leakage current from phase wire of house hold as described below.

Here actual current through household load              =          I1
Leakage Current                                                         =          I2
Current through phase measuring coil                       =          I1+I2
Current through neutral measuring coil                      =          I1
Highest of the two currents                                         =          I1+I2
So computation of energy for your house will be inflated


IV         HOW TO CHECK & REMOVE THE DEFECTs:
There is a simple check we can perform to find out whether the problem is in the new electronic meter or in the connections or household wiring etc. The current entering the meter through phase wire and coming out of the meter through neutral wire may be got checked from any qualified and experienced electrician. There could be any one of the following three observations:
  1. Incoming and outgoing current is almost the same. If such is the case, then it may be concluded that connection to the meters are ok.
  2. Outgoing current through neutral wire of meter is appreciably more than the incoming current through phase wire. If such is the case, then somebody else’s neutral wire has got connected to the neutral wire of your house and it is because of this reason that the meter is running fast. To be doubly sure, the following additional spot checks may be carried out:
    1. Disconnect the neutral or switch off the MCB if it is installed in the neutral wire (load side). If the meter is still working, it means that there is an improper neutral connection
    2. Switch off all electrical points in the house (including LEDs and indicating lamps) and check if the meter is working.  If yes, then it means that there is an improper neutral connection.  
  3. Outgoing current through neutral wire of meter is less than the incoming current through phase wire. If such is the case then it means that there is some leakage of current, earthing, etc in the building. This may be because of the old worn-out wiring in the house. To be doubly sure, following additional spot check may be carried out:
    1. Disconnect all your electrical gadgets in the house (including small indicating lamps) and see if the meter is working. If yes, then it means that some leakage of current is taking place in the building (see question 6 for details with regard to effect of leakage current on billing).
Call a qualified electrician, isolated your neutral circuit from other houses & change the wires which are causing leakage current.

*******

Thursday, August 23, 2012

Decentralised Distributed Generation in Uttarakhand......Case Study


Decentralised Distributed Generation in remote villages of Uttarakhand
[Franchisee Policy by Uttarakhand Renewable Energy Development Agency(UREDA)]

SUDHIR KUMAR SRIVASTAV
AGM-RAPDRP
NTPC LIMITED, NEW DELHI


UREDA was established in July’2001 to develop Decentralised Distributed Generation in remote villages of Uttarakhand. Around 32 micro hydel projects along with distribution network were commissioned and 19 projects are under implementation stages. Till FY 2004-05 total cost of project were borne by UREDA and after FY 2004-05, 90% of project cost are borne by UREDA and balance 10% of project cost is borne by User’s Energy Committee.

After availability of 11 KV line of UPCL under RGGVY at the project location, UREDA has connected their 05 projects with grid and supplying power to UPCL at the cost of Rs.1.63 per unit. 90% of realized money is retained with UREDA and 10% is being distributed to Energy Committee.

For the running 32 micro hydel power projects, UERDA has facilitated to form User’s Energy Committee (Gram Panchyat / Urja Samiti) and get it registered under Panchyati Raj Act / Society Registration Act 1860 / Cooperative Society Act, trained the personal and handed over the project to Committee on 30 years lease to operate the system on no profit / no loss basis. Participation of women and SC/ST were ensured in committee. All the expenses to run the project has to be borne by Energy Committee from realization bills of sold energy. UREDA shall provide financial held for capital overhaul and major break down because of natural calamity. Return on capital investment are not the part of policy.

Formation of Energy Committee:
  1. Energy committees are formed from users themselves.
  2. The executive members of the committee shall represent from each beneficiary village / hamlets.
  3. Executive committee members can be 7 –12.
  4. Energy committee should be registered and having their own byelaws and valid bank account.
  5. The Energy Committee can form 3-4 sub-committees for look after various responsibilities like:
Ø  Monitoring and supervision committee.
Ø  Material procurement committee.
Ø  Book keeping and account maintaining committee.


Role and Responsibilities of Energy Committee:
  1. Regular operation of the project.
  2. Repair and maintenance of different civil, electromechanical, transmission and distribution equipments.
  3. Fixation of tariff for different categories of beneficiaries.
  4. Regular collection of electricity bills.
  5. Regular payment to operators / technicians
  6. Allotment of new connections to consumers.
  7. Arrangement of mandatory spares.
  8. Insurance of plant and equipments.
  9. Insurance of manpower.
  10. Maintenance of O&M bank account.
  11. Book keeping and audit of accounts.
  12. Encourage for energy saving device.
  13. Tariff fixation and collection of bills.
 UREDA arranges 03 month training for committee members, its operators and technicians.

To generate sufficient income for meeting all routine and annual expenditure, fixation of tariff is done in such a way that after meeting all expenditure some reserve fund is available with Energy Committee to meet unforeseen demand. For the tariff fixation, back calculation is done. Sample back calculation for 50 KW project with 150 families and 10 commercial consumers are as below is as below

Monthly Operation & maintenance expenditure:
  1. 3 operator/technician @2500/-pm                            :           Rs.7500/-
  2. Monthly expenditure on consumables                        :           Rs.2000/-
  3. Expenditure on Insurance(@Rs18000/-pa)               :           Rs.1500/-
  4. Maintenance of civil structure                                    :           Rs.3000/-
  5. Miscellaneous Expenditure                                        :           Rs.1000/-
  6. Reserve for annual maintenance                                 :           Rs.5000/-
                     
                                                                        TOTAL:          Rs.20000/-
Monthly Income:
1. Income from domestic consumers (36x2x150)                 :           Rs.10800/-
     (@200W per family using 6 Hrs per day i.e.
     1.2 Kwh per day or 36 Kwh per month,150 family
      at Rs.2.00 per unit)
2. Income from commercial consumers (450x3x10)             :            Rs.13500/-
    (@2000W per consumer using 8 Hrs per day i.e.
    16 unit per day or 450 unit per month, 10 consumer
      at Rs.3.00 per unit)                                                                       
                                                                             TOTAL:         Rs.24300/-


    Balance available with Committee = Rs.(24300 – 20000) = Rs.4300/- pm.



    Case study of some of the projects run by Energy Committee


    1.   Karmi-I Micro Hydel Project:    Installed Capacity       :           50 KW
                                                                11 KV lines               :           5 Km
                                                                LT lines                      :           7 Km
                                                                Village covered          :           06
                                                                Families get benefited :           225
    The above project is run by “Karmi Laghu Jal Vidyut Urja Samiti”. The samiti is registered under Society registration Act-1860. Tariff decided by the Samiti are as below:
                B.P.L. Consumers                               -           Rs.30/- pm
                Consumers using 1-5 bulbs                 -           Rs.50/-pm
                Consumers using 6-10 bulbs               -           Rs.70/-pm
                Consumers using 11-15 bulbs             -           Rs.90/-pm
                Consumers using more than 15 bulbs  -           Rs.110/-pm
                For using TV                                       -           Rs.15/-pm extra

    Expenditure incurred by Samiti in one year to run the project are:
                Replacement of generator bearing      :           Rs.12000/-
                Replacement of MCCB                     :           Rs.24802/-
                Replacement of cable/conductor        :           Rs.13500/-
                Repair of equipment                          :           Rs.6500/-
                Purchase of DT                                 :           Rs.137000/-
                Payment to operators                        :           Rs.54000/-
                                                                TOTAL:         Rs.247802/-
    After meeting above annual expenditure, the Samiti is having surplus money of Rs.1,85,225/-.


    2.   Lathi Micro Hydel Project:        Installed Capacity       :           2x50 KW
                                                                11 KV lines               :           14.71 Km
                                                                LT lines                     :           21.68 Km
                                                                Village covered          :           14
                                                                Families get benefited :           216
    The above project is run by “Lathi Laghu Jal Vidyut Urja Samiti”. The samiti is registered under Society registration Act-1860. Tariff decided by the Samiti are Rs.12/- per bulb per month for all Consumers.                             -           
               
    The project is under guarantee period of manufacturer. So only payment to operator @Rs.3600/- pm is the expenditure incurred by Samiti.

    After meeting above annual expenditure, the Samiti is having surplus money of Rs.70,000/-.


    3.   Baicham Micro Hydel Project: Installed Capacity       :           2x50 KW
                                                                11 KV lines              :           6.4 Km
                                                                LT lines                    :           12.25 Km
                                                                Village covered         :           10
                                                                Families get benefited :           374
    The above project is run by “Baicham Laghu Jal Vidyut Urja Samiti”. The samiti is registered under Society registration Act-1860. Tariff decided by the Samiti are Rs.10/- per bulb per month for all Consumers.
               
    Expenditure incurred by Samiti in one year to run the project are:
                Replacement of generator carbon bush           :           Rs.5644/-
                Replacement of MCCB                                  :           Rs.13661/-
                Replacement of DT                                         :           Rs.66188/-
                DT oil & gear oil                                             :           Rs.27137/-
                Reair of turbine etc.                                        :           Rs.30461/-
                Bearing Replacement                                      :           Rs.8186/-
    Civil Work                                                      :           Rs.120400/-
    Repair of lines                                                 :           Rs.4890/-
    Replacement of cable                                      :           Rs.16931/-
    Miscellaneous expenditure                              :           Rs.23755/-
                Payment to operators                                      :           Rs.78000/-
                                                                            TOTAL:         Rs.395253/-
    After meeting above annual expenditure, the Samiti is having surplus money of Rs.1,46,317/-.

Monday, August 13, 2012

Use of Smart Meters for Grid discipline through end Consumers

Suggestion for FBB (frequency base billing) for better grid discipline
- Direct Participation of end consumers on grid discipline

SUDHIR KUMAR SRIVASTAV
DGM-RAPDRP
NTPC LIMITED, NEW DELHI

Abstract -This paper gives an insight into the various aspects of FBB (Frequency based billing), its advantage towards grid discipline through self control / regulation by consumers & utilities. The implementation of FBB though complex, but can be achieved through smart meters & shall bring about an immense improvement in grid discipline.

Keywords: FBB (Frequency based billing)

I. INTRODUCTION
Power industry in India is facing a lot of challenges like inadequate capacities in generation, transmission, and distribution, outdated technologies especially in distribution sector, poor maintenance, financial constraints, etc. Due to inadequate generation & high growth in demand, the demand supply gap is widening and peak shortages are worsening day by day.
Major impact of demand & supply gap of electricity, is on the frequency of supply i.e.  change in rotational speed of turbo-generator. Quantum change in rotational speed may lead to out of synchronism of turbo-generator, causing tripping of generator turbine & failure of supply.
As per the Regulatory Commissions Act 1998, the Central Electricity Regulatory Commission (CERC) is authorized to regulate bulk electric power tariffs, viz. the tariff for generation and transmission of power. Similarly State Electricity Regulatory Commission (SERC) is authorized to regulate the tariffs for different category of consumers.
To maintain grid discipline, CERC has introduces ABT mechanism, based on the financial principals, wherein all the Central Sector generators and beneficiaries (i.e., various States) must declare a schedule for generation and drawl for every 15 minutes one day in advance. Any deviation from the schedule is charged at UI rates, which are frequency dependent.

The possible remedies thought in ABT were:
·      Incentivize generators during peak hours.
·      Incentivize generators to back down during off- peak hours.
·      Load curtailment during low frequency & Penalties with objective:
·      Inducing better system operation and grid discipline through commercial incentives and dis-incentives.
·      Capacity charges (fixed cost): Full recovery at normative availability, Apportioned to various beneficiaries as per allocation.
·      Energy charge: Upto scheduled energy, At normative tariff.
·      Unscheduled interchange (UI): Deviation from schedule, UI are frequency linked and are payable/ recoverable depending on grid frequency.
·      Generator generates more than schedule – Gets UI
·      Generator generates less than schedule – Pays UI
·      Beneficiary overdraws power - Pays UI
·      Beneficiary under draws power– Gets UI

Though ABT has brought lot of grid discipline, still this inter-State ABT is a partial solution of the problem because of following:
·      End consumers are not penalised for over drawl during low frequency & there is no participation from end consumers towards grid discipline.
·      Frequent problem of power over drawl from State beneficiaries were observed, leading to the grid instability.
·       Some of the generators are taking advantage of ABT via playing with the loop holes of the rules. (intentional wrong declaration for undue commercial gains)
  
We propose use of FBB (Frequency Based Billing) so that the end consumers can directly participate in grid discipline.

II. SALIENT FEATURES OF FBB    
 We suggest to use SMART METERING facilities for billing the consumers as well as utilities, on the basis of frequency of supply.
If the frequency of supply is low i.e. less than   50 Hz, the consumers / utilities shall be discouraged for drawl of power by overcharging the consumption with multiplying the billed amount with (50/f) ^ 40 for consumers & with (50/f) ^ 60 for utilities.
Here denominator f is less than 50, so multiplying factor is more than 1 & consumer/utility will be overcharged.

Detail calculation at different frequency during under frequency is as below:
Similarly consumers and utilities can be incentivised during high frequency
If frequency of supply is high i.e. when frequency is more than 50 Hz, the consumers / utilities shall be encouraged to draw more power by undercharging the consumption with multiplying the billed amount with (50/f)^40 for consumers & with (50/f)^60 for utilities.

Here denominator f is more than  50, so multiplying factor is less than 1 & consumer / utility will be under charged.
 Detail calculation at different frequency during over frequency is as below.
SMART METERS shall clearly display:
1.    Frequency
2.    Multiplying factor of overcharging / undercharging.
3.    Per unit billing at current frequency.

The display may also give the information of tentative hourly / daily / monthly billing with present load & frequency conditions.
 The meter shall give alerts for high frequency & low frequency at defined / specified values.
 Meter may have facilities to auto cut the high but non-critical loads (as defined by users) when frequency is low.
This auto cut can also be graded with different level of frequency & can be associated with frequency alerts.