12 February, 2016
Mr John McMurtrie
Executive Chairman
NECA
Level 7
14 Martin Place
SYDNEY NSW 2000
Dear John
REGIONAL BOUNDARIES IN THE NATIONAL ELECTRICITY MARKET
Further to the letter on the abovementioned subject dated 29 October 1997 where NEMMCO
requested that its Regional Boundaries recommendation (NEMMCO letter of 16 October
1997) be withdrawn, I am now pleased to forward you a NEMMCO recommendation which
has been determined strictly according to the criteria set out in clause 3.5.1 (b) 2 of the NEM
Code.
NEMMCO convened a meeting of the TIRC on Friday 31 October 1997 to review its earlier
assessment of the four options previously evaluated, particularly considering issues raised at
the participant forum of 23 September which were relevant to the assessment criteria set out
in clause 3.5.1 (b) 2 of the NEMM Code.
Following a considered review of all options against the code evaluation criteria, the TIRC
determined that only one element in the evaluation should be changed. This was the
downgrading of option 3 in terms of code principle (iii) - “regional boundaries should be
located so that regions can be clearly defined and transfer flows across regions easily
measured at the region boundary.”
Option 3 (which is best from the viewpoint of managed loss factors) has regional boundaries
which intersect the meshed Transmission Network in South Australia, Northern Victoria and
Southern NSW. This causes power flow limits to be difficult to calculate and measure.
NECA in its letter to NEMMCO dated 2 October highlighted its concerns on this issue in
respect of South Australia. A revised evaluation is attached.
In addition option 3 is presently not NEM Code compliant due to an existing Victorian
derogation.
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In summary, following a careful review by the TIRC, NEMMCO confirms its earlier
recommendation that option 2 (Snowy Generation in a separate region) be approved by
NECA. NECA should note that this recommendation is backed by an evaluation performed
strictly according to the criteria set out in the NEM Code.
Yours sincerely
W S van der Mye
Managing Director
enc:
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ALIGNMENT OF OPTIONS WITH CODE PRINCIPLES
The following schedule compares each of the four options with the seven selection criteria
detailed in the NEM Code.
Code Principle
Option 1
Option 2
Option 3
Option 4
i)
Enclosed regions
(10)
***
30
***
30
***
30
***
30
ii)
Constraints do not
affect dispatch
Limits defined and
measurable
Loss factors
approximate
optimal dispatch
Low errors in all
loss factors
Low errors in intraregional loss
factors
Minimal number of
regions
(9)
*
9
***
27
***
27
***
27
(8)
***
24
***
24
*
8
**
8
(7)
*
7
***
21
***
21
***
21
(5)
*
6
**
12
***
18
**
12
(5)
*
5
**
10
***
15
**
10
(4)
***
12
**
8
**
8
**
8
iii)
iv)
v)
vi)
vii)
Score
93
132
127
124
Max 147
Note 1:
The numbers in () give the weighting for each Code principle. The 1 to 3 is
used to multiply the weighting to give an overall score. Eg Score for Code
Principle (i) is 10 x 3 = 30. Recommended Option 2 has score of 132 out of
max 147.
Legend:
*** = best alignment
* = worst alignment
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