Before the
MAHARASHTRA ELECTRICITY REGULATORY COMMISSION
th
13 Floor, Centre No.1, World Trade Centre, Cuffe Parade, Mumbai- 400 005
Tel: 022 - 22163964/65/69 Fax: 022 - 22163976
E-mail: mercindia@merc.gov.in
Website: www.merc.gov.in / www.mercindia.org.in
CASE No. 52 of 2015
In the matter of
Petition of Tata Power Company Ltd. (Generation Business) for revised norms for
Hydro Auxiliary Consumption for FY 2015-16
Coram
Shri Azeez M. Khan, Member
Shri Deepak Lad, Member
Tata Power Company Ltd.
..... Petitioner
Appearance
For the Petitioner
:
Shri A.S. Mhapsekar (Rep.)
Consumer Representative
:
Dr. Ashok Pendse, TBIA
ORDER
Dated: 22 February, 2016
1. M/s. Tata Power Company Ltd. (Generation Business) (TPC-G) filed a Petition on
7 April, 2015 under Regulation 100 of the MERC (Multi Year Tariff) Regulations,
2011 (‘the MYT Regulations’) seeking approval of additional Auxiliary
Consumption norms for FY 2015-16 for its Hydro Generating Stations.
2. TPC-G’s prayers are as follows:
“
a. Approve the additional Norms of GT losses – 1.13% & Head work Losses of
0.33% for Hydro Generating Stations.
b. Condone any inadvertent omissions/errors/shortcomings and permit Tata
Power-G to add/change/modify/alter this filling and make further submissions
as may be required at a future date.
c. Pass any other such directive as that the Hon’ble Commission may deem
appropriate in the facts and circumstances of the case.”
Order in Case No. 52 of 2015
Page 1
3.
In its Petition, TPC-G has submitted that:3.1 TPC-G has three Hydro Electric Generating Stations at Bhira, Bhivpuri and
Khopoli in Raigad Distt., Maharashtra, with total generating capacity of 447 MW.
These Hydro Generating Stations have a large geographical spread with a complex
water system consisting of gate operations at multiple lake reservoirs, inter-lake
water transfer systems, valve houses at various locations, open canal water
conductor system, forebay, tunnels and penstocks. This requires geographically
spread control points at critical locations, entailing significant Auxiliary
Consumption for all Head Works distribution systems.
3.2 Further, the geographical spread of operational locations requires distribution
transformers for providing power supply for operating the equipments at various
locations. The losses of these transformers are not included in the Auxiliary
Consumption of the Hydro Stations.
3.3 All Hydro Stations, including associated Head Works, are at remote locations.
Hence, setting up of housing colonies for operational staff is an operational
imperative. The energy consumption at these locations is an operational
requirement, which is not factored into the Auxiliary Consumption norm.
3.4 All the Hydro Generating Units at TPC-G’s Hydro Stations are small Units (24-25
MW) except for the 150 MW Bhira Pumped Storage Unit. This translates into a
large number of generator transformers and, hence, higher generator transformer
losses (GT Losses) as these transformers are kept back-charged when the
Generation Unit is backed down. Considering this fact, the current norm of 0.5%
towards GT Losses is grossly inadequate. This is primarily on account of smaller
size of Generating Units as compared to the normal size of Hydro Generating Units
in other Plants.
3.5
In its Business Plan and MYT Petition, TPC-G had submitted these facts to the
Commission. However, in its Business Plan Order in Case No 166 of 2011 dated 9
August, 2012, the Commission had stated as follows:
“As regards the inclusion of colony consumption as a part of auxiliary
consumption, the Commission is of the view that energy consumption by the
housing colonies at the hydro Stations cannot be considered as a part of the
auxiliary consumption, and it can be accounted for under excess O&M
expenses. Further, TPC-G in its submissions made in the context of the
Commission’s Order dated 15 February, 2012 in Case No. 105 of 2011
submitted that the consumption of colonies has not been added as a part of
auxiliary consumption and forms a part of Transmission and Distribution
Losses. The Commission, in the said Order, directed TPC-G to separately
measure the consumption of the colonies and report the same to the
Commission. Further, TPC-G should not include the colony consumption as
part of T&D losses and should propose an appropriate mechanism for
accounting of colony consumption as per statutory and regulatory
provisions.
As regards head work distribution system loss, the Commission is of the
view that such loss cannot be included in auxiliary consumption as it does
Order in Case No. 52 of 2015
Page 2
not by any means come under auxiliary consumption. Such requirement of
the head work distribution system is common for almost all hydro Stations
and does not represent any special case. Therefore, to this extent no
modification has been considered by the Commission.
The Commission, in the MERC MYT Regulations, has specified the
Transformation Loss as 0.50% of the energy generated, and the
Transformation Losses of (17.31 MU) 1.27% as submitted by TPC-G is very
much on the higher side. TPC-G submitted that this is on account of smaller
size of generating units. The Commission is of the view that the impact of the
smaller units cannot be quantified with certainty and a proper study may
have to be carried out to calculate such impact and steps to be taken to
reduce such losses. The outcome of such study can be then appropriately
incorporated at the time of mid-term performance review and norms cannot
be relaxed at this point of time.
As regards the energy consumption of about 0.28% (3.78 MU, average of
past five years) for the nallah diversion schemes to utilise the water, which
otherwise flows outside the basin and hence, gets wasted, the Commission in
its data gaps asked TPC-G to submit the generation benefit due to such
consumption of energy to divert these nallahs. TPC-G, in its reply,
submitted that these schemes pump the water into the lakes with heads
ranging from 10 metres to 50 metres. However, the head available for
generation becomes 500 metres, giving a benefit of approximately ten times
generation to that of energy consumed. TPC-G also submitted generation
achieved on account of such pumped water vis-à-vis the energy consumed
for pumping this water for the period 2005 to 2011 showing the benefits of
pumping water, as shown in the Table below:….
…The Commission is of the view that such energy on account of the nallah
diversions is being consumed for improving the inflow of water into the
lakes and enables additional generation, which benefits the consumers. The
Commission has hence, considered the relaxation in the auxiliary
consumption norms for hydro Stations to the extent of 0.28% as proposed by
TPC-G.
The summary of the existing and the revised norms for auxiliary
consumption of hydro Stations for the second control period is as shown in
the table below:
Table -1: Auxiliary Consumption for hydro Stations as approved by the
Commission for the second control period (FY 2012-13 to FY 2015-16)
Particulars
Auxiliary Consumption
Pumping Energy for Nallah Diversion
Transformation Losses
Total Auxiliary Consumption
Existing Norm Revised Norm
1.00%
0.50%
1.50%
1.00%
0.28%
0.50%
1.78%
”
3.6 Considering the above, TPC-G had appointed Central Power Research Institute (CPRI)
to carry out an assessment and study of the GT losses at all its Hydro Generating
Order in Case No. 52 of 2015
Page 3
Stations. The comparison between the approved norm of the Commission, GT Losses
as per CPRI study and actual GT losses (for FY 2012-13) is given below:
GT losses as approved vs. as measured by CPRI
Station
Khopoli
Bhivpuri
Bhira
Hydro
Approved Norm
%
0.5
0.5
0.5
0.5
As per CPRI
%
1.19
1.17
1.09
1.13
Actual
%
1.59
1.50
2.11
1.88
Thus, the actual GT losses measured by CPRI work out to 1.13 % as compared to
0.5% approved by the Commission. Hence, the norm for GT losses for FY 2015-16
may be approved as per the CPRI report.
3.7 In its Business Plan approval Order in Case No. 166 of 2011, while disallowing the
Head Works losses, the Commission opined that such consumption cannot be
classified under the Head of Auxiliary Consumption.
3.8 The Auxiliary Energy Consumption under Head Works is significant on account of the
large geographical spread of the Hydro Stations, with a complex water system
consisting of gate operations at multiple lake reservoirs, inter-lake water transfer
systems, and valve houses at various locations, open canal water conductor system,
forebay, tunnels and penstocks. This requires geographically spread control points at
critical locations requiring significant power consumption for its Head Works
distribution system.
3.9 In order to compute the Head Work consumption also, TPC-G had appointed CPRI
to carryout assessment of the Auxiliary losses at all the Hydro Generating Stations.
The CPRI assessment is shown in the Table below:
Head Work consumption measured by CPRI vs Actual for Hydro
3.10 The Head Work consumption as per the CPRI assessment is 0.33%, which is quite
significant. Hence, the Commission may approve the norms of Head Works
consumption based on the CPRI Report.
3.11 Additionally, in view of the uniqueness of the Khopoli Hydro Generating Station,
TPC-G, the Commission may approve the Head Works consumption for that
Station based on the actuals as it is lower by 0.06% as compared to the CPRI study
Order in Case No. 52 of 2015
Page 4
to the extent of 0.67% on overall Hydro Generation. In case of any deviation from
the above norms in actual Consumption, the lower of the two may be considered.
3.12 In summary, the Commission may approve the normative Auxiliary Consumption for
FY 2015-16 as follows:
i)
ii)
4.
GT losses – 1.13% &
Head Work Losses- 0.33%
At the hearing held on 5 January, 2016, TPC-G made a presentation and reiterated
the submissions in its Petition. It stated that it had sought revision of the Auxiliary
Consumption norms for FY 2015-16 based on the CPRI Report on its Hydro
Generating Stations, and cited Regulation 100 of the MYT Regulations, 2011 which
empowered the Commission to remove difficulties. The Petition had been filed
prior to the Commission’s Mid Term Review (MTR) Order dated 26 June, 2015.
Dr. Ashok Pendse, on behalf of Thane-Belapur Industries Association (TBIA), an
Authorised Consumer Representative, submitted that the Commission has already
considered the findings of CPRI in its MTR Order for TPC-G. While TPC-G had
itself appointed CPRI for the study and the Commission had accepted it, TPC-G is
now challenging it. It should have first discussed the finding and recommendations
with CPRI.
Commission’s Analysis and Ruling
5.
Any revision in Auxiliary Consumption norms has a corresponding impact on
the Tariff of Hydro Generating Stations. TPC-G had filed its MTR Petition in
Case No. 6 of 2015 for the period from FY 2011-12 to FY 2015-16 and seeking
approval for revised projections and Tariff for FY 2015-16. The MTR Petition
was filed by TPC-G prior to the present Petition.
6.
In its MTR Petition, TPC-G had considered the normative Heat Rate and
Auxiliary Consumption for computing the Energy Charges for FY 2015-16,
and no additional or revised norms were sought for FY 2015-16 in respect of
Hydro Auxiliary Consumption. The MTR proceedings would have been the
appropriate forum for raising the issue of revised norms for TPC-G’s Hydro
Generating Stations for FY 2015-16.
7.
The Commission notes that, although no relaxation in the Auxiliary
Consumption norms for FY 2015-16 was specifically sought, while seeking
Truing up for previous years in its MTR Petition, TPC-G had referred to the
findings of the CPRI Report and sought approval of the actual Auxiliary
Consumption towards GT Losses and Head Works for FY 2012-13 and FY
2013-14.
8.
In its MTR Order dated 26 June, 2015 in Case No. 6 of 2015, the Commission
has addressed the issue of GT Losses and Head Work Losses of TPC-G’s
Hydro Stations. It cited and discussed the CPRI findings and
Order in Case No. 52 of 2015
Page 5
recommendations while declining to approve relaxed norms for Hydro
Auxiliary Consumption on account of GT losses. TPC-G’s submissions
regarding Hydro Auxiliary Consumption relating to Head Works losses were
also not accepted by the Commission. The relevant paras. of the Order read as
follows:
9.
“4.1.2.21 The MYT Regulations specify the norms of Auxiliary
Consumption of Hydro Stations. The norm applicable is 1% (for machines
with Static Excitation systems) with an additional 0.5% for transformation
losses. In addition, the Commission in the MYT Order has considered
relaxation in Auxiliary Consumption to the extent of 0.28% on account of
pumping energy for Nallah diversion. Accordingly, the Commission
specified the normative Auxiliary Consumption of 1.78% for the Hydro
Stations.
4.1.2.22 As regards the transformation losses, the Commission in its
Business Plan Order dated in Case No. 166 of 2011 held as under:
“The Commission, in the MYT Regulations, has specified the
Transformation Loss as 0.50% of the energy generated, and the
Transformation Losses of (17.31 MU) 1.27% as submitted by TPC-G is
very much on the higher side. TPC-G submitted that this is on account
of smaller size of generating units. The Commission is of the view that
the impact of the smaller units cannot be quantified with certainty and
a proper study may have to be carried out to calculate such impact and
steps to be taken to reduce such losses. The outcome of such study can
be then appropriately incorporated at the time of mid-term performance
review and norms cannot be relaxed at this point of time.”
4.1.2.23 TPC-G has sought relaxation in norms of Auxiliary Consumption
for the Hydro Stations based on the CPRI findings. The Commission has
scrutinized reports of the study conducted by CPRI for three Hydro
Stations, viz. Bhira, Bhivpuri and Khopoli.
4.1.2.24 TPC-G contended that the higher transformation losses were on
account of the smaller generating Units. The object of the study was to
quantify the impact of the smaller generating units on the transformation
losses. The Commission observes that the scope of the CPRI study was to
quantify the Auxiliary Consumption in the Hydro Stations and suggest
energy conserving measures. CPRI has computed the actual
transformation losses for Hydro Stations considering the existing system,
and observed as follows:
“The GT losses are on higher side may be due to ageing. These transformers
may be replaced with new energy efficient transformers to reduce the
auxiliary power on long run basis.”
4.1.2.25 In case of Bhira Hydro Station, CPRI has also made the
following observation:
“Figure 8 gives the variation of generator transformer loss for one year
and is varying between 0.96 to 1.26 %. The GT loss variation is more may
be due to metering error.
Order in Case No. 52 of 2015
Page 6
Recommendations: It is suggested to calibrate all the energy meters at
least once in two years to account the auxiliary power appropriately”
4.1.2.26 The Commission is of the view that the CPRI reports do not
justify the impact of the small generating units on the transformation
losses, as contended by TPC-G. Moreover, based on the observations
made, it may be noted that the transformation losses are within the control
of TPC-G. The Commission finds no merit in considering the
transformation losses over and above the normative losses of 0.50%. The
Commission has considered the GT losses of 0.5% for the Hydro Stations.
4.1.2.27 As regards the Headworks distribution system loss, the
Commission has already taken the view that such loss cannot be included
in Auxiliary Consumption. Such requirement of the Headworks
distribution system is common for almost all Hydro Stations and does not
represent any special case. Therefore, the Commission has not considered
any relaxation in Auxiliary Consumption norms on account of Headworks
distribution loss.
10.
4.1.2.28 The Commission has considered the approved normative
Auxiliary Consumption of 1.78% for Hydro Stations for truing up
purposes. ”
9.
Thus, the findings of the CPRI Report cited now by TPC-G in support of its
contentions were fully considered and analysed by the Commission in the
MTR Order. Based on this analysis, the Commission did not consider it
appropriate to approve any relaxation in Hydro Auxiliary Consumption on
account of higher GT Losses and Head Works distribution system over and
above the approved norms.
10.
In view of the foregoing, the Commission is not inclined to allow any additional
or revised Auxiliary Consumption norms over and above the already approved
norms for its Hydro Generating Stations for FY 2015-16, as sought by TPC-G.
The Petition of M/s. Tata Power Company Ltd. (Generation Business) in Case No.
52 of 2015 stands disposed of accordingly.
Sd/(Deepak Lad)
Member
Order in Case No. 52 of 2015
Sd/(Azeez M. Khan)
Member
Page 7