17_Order_dt_10_04_2006_CN_01 of 200500011

Document Sample
17_Order_dt_10_04_2006_CN_01 of 200500011 Powered By Docstoc
					ORDER ON TARIFF DETERMINATION FOR BHEP II
                     90% Dependable yield(1972-73)           90% Dependable yield(2000-01)          Average of 90% Dependable yield
       Month               Energy     No. of    No. of            Energy      No. of   No. of              Energy      No. of    No. of
                  Capacity Generated Hours      days     Capacity Generated Hours      days     Capacity   Generated   Hours     days
           1         2          3         4        5        6          7         8        9        10          11              12     13
March (16-31)      28.34      0.11       4.0      1       33.11      0.09       2.7       1       30.72        0.10           3.36    1.00
April (1-15)       31.67      1.93       4.1      15      37.48      1.81       3.2      15       34.58        1.87           3.64   15.00
April (16-30)      31.53      0.11       3.3      1       37.48      0.09       2.3       1       34.50        0.10           2.84    1.00
May (1-15)         33.80      2.00       3.9      15      37.48      1.86       3.3      15       35.64        1.93           3.62   15.00
May (16-31)        38.23      0.06       1.5      1       37.48      0.04       1.0       1       37.86        0.05           1.27    1.00
        Total                 36.99             254.00               40.78             263.00                 38.88                  258.50




                                                                                                                    Page 41 of 45
A11: APPENDIX G - REPORT FROM COMMISSION’S
     TECHNICAL EXPERT
Note on BHEP II
Ref:GOMWRD letter dated 02-Mar-2006; DLH letter dated 24-01-2006.

General

The Government of Maharashtra and M/s DLH had furnished studies in response to
discussions held in Jan, 06 at Mumbai with the MERC. The studies have been reviewed to
arrive at the energy generation from BHEP II in a 90% dependable year in the different
phases of Pravara river basin development.

The Government of Maharashtra had analyzed the runoff data at Bhandardara Dam from
1976 to 2004 to arrive at the 90%, 50% and 75% dependable yields. As per these studies,
2000-01 (June to May) with a total inflow of 292 MCM and 1972-73 with total annual inflow
of 322 MCM are considered as 90% dependable years. As per assessment of DLH, 2000-01
constitutes 90% dependable year based on discharge data from 1965 to 2004.

Considering that year 2000-01 has a lesser inflow, the assessment of power benefits from
BHEP II project in a 90% year based on the studies for 2000-01 would be in order.

M/s DLH had furnished the detailed daily working tables for 90% dependable year in the pre
Nilwande phase. They had also carried out studies post Nilwande corresponding to the dam
construction to level of +613m and FRL +648m for 50%, 75% & 90% dependable years.
These studies were carried out considering the historical daily outflows from Bhandardara
and flow from the free catchment at Randha weir. The inflows from free catchment between
Bhandardara dam and Randha weir has been assessed taking into account the ratio of
catchment area and rainfall.

During the discussions held in Jan 06 at Commission’s office, working table studies on
monthly basis in pre Nilwande and post Nilwande (+613 m/ 648 m) were furnished by
Government of Maharashtra. The working table studies (on fortnightly basis) now
(March,06) furnished by GoM are for post Nilwande Dam for FRL +648 m for 50%, 75%
and 90% dependable years. In all these studies, inflows from free catchment between
Bhandarda dam and Randha weir have been considered as 20% of flows at Bhandardara
Dam.

The power potential of the project in 90% dependable year in the various phases of basin
development (pre and post Nilwande) are discussed in the following

Pre – Nilwande Phase:

In the studies furnished by GOMWRD for pre - Nilwande phase, the power potential of the
project in 90% dependable year was assessed as 44 MU. These studies did not take into
account the minimum discharge limitations of the TG set of BHEP II. The working tables as




                                                                                       42
ORDER ON TARIFF DETERMINATION FOR BHEP II

indicated in the foot note would not represent the correct situation and cannot be considered
for determination of power potential of BHEP II in the pre - Nilwande stage.

The studies of M/s DLH were done considering the actual daily releases from Bhandardara
dam during 2000-01. In these studies, the lower discharge limit (34 cumec) for turbine
operation at BHEP II has been taken into account. On this basis, the power potential of the
project in 90% dependable year has been assessed as 33.5 MU. In these studies, the overall
efficiency of 83% has been adopted, while as per information furnished by GOMWRD, the
overall efficiency should be 84.6%. correcting for lower efficiency, the energy benefit from
BHEP II in a 90% year would be 34.1 MU.

Without Nilwande dam, BHEP II cannot be operated for peaking though Pondage is available
at Randha weir. This constraint is in on account of the fact that there is no re-regulating
pondage at the irrigation weir to even out pulsating peaking releases. Further, t whenever
releases available for power generation are less than 34 cum, the same cannot be utilized for
power generation for BHEP II since this is the lower limit of turbine operation range..
Accordingly in pre Nilwande phase, BHEP II will operate as run of the river project and the
generation will depend on the irrigation discharges and there would be periods of power
house closure on account the reasons beyond the control of the project operator.

The annual energy potential of BHEP II in a 90% dependable could be taken as 34.1 MU and
the project would operate as ROR project with periods of shut down dictated by the irrigation
requirements.

Post-Nilwande Dam (+613 m)

The studies of GOMWRD furnished in Jan 2006 indicated the energy generation in 90%
dependable year as 49.6 MU. In this study the total water utilized for power generation has
been indicated as about 368 mcm. It would appear that this has been arrived at based on
earlier analysis in which 90% dependable flows at Bhandardara were taken as average of the
flows for 1972-73 and 2000-01.

M/s DLH in their studies assessed the potential at 42.8 MU in 90% dependable year
considering the historical outflows from Bhandaradara dam and additional inflow of 61MCM
from free catchment at randha weir. The overall efficiency in this study is taken as 83%.
Correcting for the efficiency to 84.6%, the energy generation would be 43.4 MU.

In this phase of development, with the re-regulation pondage available at Nilwande,it would
be possible to operate BHEP II for peaking. The pre Nilwande constraint in operation of
BHEP II during periods of flows lower than 34 cumec would no longer be applicable. Power
generation would be possible even during the periods of release of less than 34 cume, by
utilizing the pondage available at Randha Weir. However, during the periods when no waters
are to be released from Bhandardara, BHEP II would not be in a position to generate power.
This situation is on account of the irrigation cycle and utilization of waters primarily for
irrigation.

The annual energy generation from BHEP II in post Nilwande (+613m) phase would be 43.4
MU. Peaking benefit to the extent of 34 MW would be available except during periods of no
irrigation releases from Bhandaradara.



                                                                                   Page 43 of 45
ORDER ON TARIFF DETERMINATION FOR BHEP II


Post - Nilwande Dam (+648 m)

GOMWRD carried out integrated operation studies for Bhandaradara nd Nilwande dams
together and took into account the irrigation requirements downstream at Nilwande and
Ozhar weir. These studies had considered the 90% dependable year inflows into Bhandardara
reservoir as 292 MCM. The energy generation from BHEP II had been assessed taking into
account the impact of higher tail water level on account of Nilwande. In these studies the
power potential of BHEP II has been assessed as 40.78 MU for 90% dependable year (2000-
01). In the studies, the initial water level in Bhandardara reservoir was taken as 714.3 m (42
MCM gross storage) and the final level at the end of the year was shown as 698 m (8 MCM
gross storage). Thus there was an additional utilization of 34 MCM from the carry over
storage. The energy assessments in the studies would need to be corrected for the additional
utilization of carry over waters from previous year. The energy generation on account of this
additional water is 4.52 MU (taking approx. 0.133 MU for 1 MCM of releases). If this
correction is taken into account the 90% dependable potential for Bhandardara would be
36.26 MU.

DLH has assessed the potential for this phase as 34.8 MU. Correcting for the efficiency 83%
to 84.6%, the power potential would work out 35.4 MU. The difference between the two
energy assessments could be on account of the difference in assumptions made by DLH. The
tail water level in GOMWRD studies would be appropriate as they take into account the
integrated operation of the all the developments in the river basin and also consider irrigation
releases at Nilwande and Ozar.

In this phase (post Nilwande +648m) of development, as per GOMWRD studies, the energy
generation would be possible for 263 days i.e. 72% of the time. The peaking capability would
however, reduce during periods of high TWL when the water level in Nilwnde is high and
the head available for power generation falls below design head.

BHEP II is a component of the integrated development of the water resource of Pravara basin
primarily for irrigation. The operation of the plant would therefore have to follow the
irrigation pattern. There would be periods of no generation of power at BHEP II on account
of irrigation dependent operation of the storage reservoirs. This is beyond the control of the
plant operator.




                                                                                      Page 44 of 45

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:5
posted:1/6/2013
language:Unknown
pages:4