42 km, slightly less favourable than the initial
investment analysis. When
looking the 20-year operational net present
value (NPV), the break-even length increases to
4. Because distribution lines require
rectifiers and inverters both ends, the benefits
of conversion increase with the length the
submarine cable section.
In this scenario, the maximum continuous
operating capacity the high-capacity 22.1 Distribution submarine cable
First scenario: existing submarine cable is
converted realize additional operating
capacity, avoiding investment new cable
installation, shown Figure A-1.
Figure A-1 MVDC replacement for submarine cable scenario
Figure A-2 Submarine cable MVDC economics based initial investment (left) and 20-year
operational NPV (right)
0
5
11
16
21
26
32
37
42
7
10
12 15
18
20
23
25
28
0
10
20
30
40
50
0 8
USD(M$)
FEEDER LENGTH (KM)
Initial Investment Cost
AC Investment Cost
DC Investment Cost
0
6
12
18
25
31
37
43
49
14
17
20
23
26 29
32
35
38
0
10
20
30
40
50
60
1 8
USD(M$)
FEEDER LENGTH (KM)
20-Year NPV NPV
DC NPV
. Therefore, integrating a
30 MVA distributed generator load would require
two distribution lines.9 AC
distribution line MVA. Figure A-2 shows the investment
cost comparison for and distribution lines
at various submarine cable lengths. Converting the system to
DC ±35 kV, however, doubles the capacity: single
DC line can accommodate additional
generation load, resulting investment
savings. The construction cost of
a submarine cable assumed approximately
USD 264/km.62 km.71
Annex Case studies MVDC economics
A. The latter outcome due to
the maintenance costs the converters.
Based initial investment costs, MVDC achieves
an economic advantage over MVAC submarine
cable length approximately 2
