IEEE Power & Energy Magazine - March/April 2015 - 93

however they typically offer around
US$0.06/kwh, close to the wholesale
value of the energy. The network savings
including reduced losses don't get factored in here as they have been deemed
by regulators to be immaterial and too difficult to measure. while demand-related
revenue is being threatened and even peak
loads are fairly stable, network tariffs have
risen very considerably over the past five
years, more than doubling in some cases.
A number of government inquiries into
these price increases have suggested that
network gold plating driven by inappropriate incentives in the regulation of network businesses (particularly an assured
return on approved capital expenditure)
has been a major driver.

Where Next-Punish PVs
or Rethink Network
Business Models?
A range of DnSP, regulator, and policy
maker proposals have been put forward
to address the technical challenges and
revenue problems now being experienced
by Australian DnSPs. Technically oriented management proposals, some now
implemented, include hosting limits that
restrict new PVs in parts of the network
with significant existing PVs believed
to be already causing issues, capping the
allowed size of systems, and even banning exports from PV systems. Some PV
installers doing larger commercial and
industrial PV systems have also argued
that there are DnSPs using high and nontransparent fees and long time frames for
network studies, along with onerous and
excessive technical requirements, to slow
the uptake of PVs. There are even some
proposed restrictions on dc injection, ramp
rates, and protection requirements beyond
current inverter standards such as AS4777.
There are, of course, valid reasons
for the concerns of DnSPs and regulators over growing distributed PV deployment. However, in our view, some of the
changes, existing and proposed, being
put forward in response could potentially
discriminate against a highly promising and beneficial distributed generation
technology and hence slow the clean energy transition that our electricity industry so desperately requires.
march/april 2015

First, PV-related technical issues are
often difficult to separate from other
distribution network issues caused by
a range of end-user equipment and
behavior. For example, the main voltage challenge for many parts of the
Australian distribution network is actually periods of low voltage when highly
correlated, high-power, household air
conditioners are running. In response,
the DnSPs have often set distribution
transformer voltages near the upper
limit of the permitted voltage range,
potentially causing high-voltage problems at times of low load independently
of PVs (typically overnight) and leaving little headroom for distributed generation to export into the network. In
such cases, is it the PV system or the
air conditioners that are most contributing to voltage management problems?
At present, PV inverters are required
to switch off when the voltage goes too
high; indeed, our DnSP survey suggested
that this was one of the
most common problems
caused by PVs. The
inverter disconnecting
is in itself not causing
a problem for DnSPs
but rather helping solve
one. However, there is
the matter of the power
quality investigation
triggered by irate owners
wondering why their PV
system keeps turning off
in the middle of the day.
By comparison, air conditioners and other loads
don't generally monitor
the supply voltage and
help address low-voltage problems by modifying their own operation. you might ask why
PV households have to
solve a problem that arguably is caused by the
high transformer tap settings required to manage
low-voltage problems
caused by air conditioners in other houses? In a
similar manner, some of

the harmonics and power factor issues commonly associated with PVs are not caused
by the unity power factor and very low harmonic output of the PV inverter itself but,
instead, the remaining power factor and
harmonics from badly behaving loads now
seen by the DnSP's network equipment.
with regard to the various revenue solutions being put forward, a number of
studies (albeit contested), including one
commissioned by the Australian Energy
Market commission, do indicate that
network savings from peak load reduction from PVs are generally less than the
value of the network tariff avoided by
such customers under current net metering. This is largely due, of course, to the
relatively poor alignment between PV
output and these network peak loads that
generally occur in the evening. This does
certainly represent an implicit subsidy
from households without PV systems to
those with the systems. However, PVs
are hardly alone in an environment where

ieee power & energy magazine

93



Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - March/April 2015

IEEE Power & Energy Magazine - March/April 2015 - Cover1
IEEE Power & Energy Magazine - March/April 2015 - Cover2
IEEE Power & Energy Magazine - March/April 2015 - 1
IEEE Power & Energy Magazine - March/April 2015 - 2
IEEE Power & Energy Magazine - March/April 2015 - 3
IEEE Power & Energy Magazine - March/April 2015 - 4
IEEE Power & Energy Magazine - March/April 2015 - 5
IEEE Power & Energy Magazine - March/April 2015 - 6
IEEE Power & Energy Magazine - March/April 2015 - 7
IEEE Power & Energy Magazine - March/April 2015 - 8
IEEE Power & Energy Magazine - March/April 2015 - 9
IEEE Power & Energy Magazine - March/April 2015 - 10
IEEE Power & Energy Magazine - March/April 2015 - 11
IEEE Power & Energy Magazine - March/April 2015 - 12
IEEE Power & Energy Magazine - March/April 2015 - 13
IEEE Power & Energy Magazine - March/April 2015 - 14
IEEE Power & Energy Magazine - March/April 2015 - 15
IEEE Power & Energy Magazine - March/April 2015 - 16
IEEE Power & Energy Magazine - March/April 2015 - 17
IEEE Power & Energy Magazine - March/April 2015 - 18
IEEE Power & Energy Magazine - March/April 2015 - 19
IEEE Power & Energy Magazine - March/April 2015 - 20
IEEE Power & Energy Magazine - March/April 2015 - 21
IEEE Power & Energy Magazine - March/April 2015 - 22
IEEE Power & Energy Magazine - March/April 2015 - 23
IEEE Power & Energy Magazine - March/April 2015 - 24
IEEE Power & Energy Magazine - March/April 2015 - 25
IEEE Power & Energy Magazine - March/April 2015 - 26
IEEE Power & Energy Magazine - March/April 2015 - 27
IEEE Power & Energy Magazine - March/April 2015 - 28
IEEE Power & Energy Magazine - March/April 2015 - 29
IEEE Power & Energy Magazine - March/April 2015 - 30
IEEE Power & Energy Magazine - March/April 2015 - 31
IEEE Power & Energy Magazine - March/April 2015 - 32
IEEE Power & Energy Magazine - March/April 2015 - 33
IEEE Power & Energy Magazine - March/April 2015 - 34
IEEE Power & Energy Magazine - March/April 2015 - 35
IEEE Power & Energy Magazine - March/April 2015 - 36
IEEE Power & Energy Magazine - March/April 2015 - 37
IEEE Power & Energy Magazine - March/April 2015 - 38
IEEE Power & Energy Magazine - March/April 2015 - 39
IEEE Power & Energy Magazine - March/April 2015 - 40
IEEE Power & Energy Magazine - March/April 2015 - 41
IEEE Power & Energy Magazine - March/April 2015 - 42
IEEE Power & Energy Magazine - March/April 2015 - 43
IEEE Power & Energy Magazine - March/April 2015 - 44
IEEE Power & Energy Magazine - March/April 2015 - 45
IEEE Power & Energy Magazine - March/April 2015 - 46
IEEE Power & Energy Magazine - March/April 2015 - 47
IEEE Power & Energy Magazine - March/April 2015 - 48
IEEE Power & Energy Magazine - March/April 2015 - 49
IEEE Power & Energy Magazine - March/April 2015 - 50
IEEE Power & Energy Magazine - March/April 2015 - 51
IEEE Power & Energy Magazine - March/April 2015 - 52
IEEE Power & Energy Magazine - March/April 2015 - 53
IEEE Power & Energy Magazine - March/April 2015 - 54
IEEE Power & Energy Magazine - March/April 2015 - 55
IEEE Power & Energy Magazine - March/April 2015 - 56
IEEE Power & Energy Magazine - March/April 2015 - 57
IEEE Power & Energy Magazine - March/April 2015 - 58
IEEE Power & Energy Magazine - March/April 2015 - 59
IEEE Power & Energy Magazine - March/April 2015 - 60
IEEE Power & Energy Magazine - March/April 2015 - 61
IEEE Power & Energy Magazine - March/April 2015 - 62
IEEE Power & Energy Magazine - March/April 2015 - 63
IEEE Power & Energy Magazine - March/April 2015 - 64
IEEE Power & Energy Magazine - March/April 2015 - 65
IEEE Power & Energy Magazine - March/April 2015 - 66
IEEE Power & Energy Magazine - March/April 2015 - 67
IEEE Power & Energy Magazine - March/April 2015 - 68
IEEE Power & Energy Magazine - March/April 2015 - 69
IEEE Power & Energy Magazine - March/April 2015 - 70
IEEE Power & Energy Magazine - March/April 2015 - 71
IEEE Power & Energy Magazine - March/April 2015 - 72
IEEE Power & Energy Magazine - March/April 2015 - 73
IEEE Power & Energy Magazine - March/April 2015 - 74
IEEE Power & Energy Magazine - March/April 2015 - 75
IEEE Power & Energy Magazine - March/April 2015 - 76
IEEE Power & Energy Magazine - March/April 2015 - 77
IEEE Power & Energy Magazine - March/April 2015 - 78
IEEE Power & Energy Magazine - March/April 2015 - 79
IEEE Power & Energy Magazine - March/April 2015 - 80
IEEE Power & Energy Magazine - March/April 2015 - 81
IEEE Power & Energy Magazine - March/April 2015 - 82
IEEE Power & Energy Magazine - March/April 2015 - 83
IEEE Power & Energy Magazine - March/April 2015 - 84
IEEE Power & Energy Magazine - March/April 2015 - 85
IEEE Power & Energy Magazine - March/April 2015 - 86
IEEE Power & Energy Magazine - March/April 2015 - 87
IEEE Power & Energy Magazine - March/April 2015 - 88
IEEE Power & Energy Magazine - March/April 2015 - 89
IEEE Power & Energy Magazine - March/April 2015 - 90
IEEE Power & Energy Magazine - March/April 2015 - 91
IEEE Power & Energy Magazine - March/April 2015 - 92
IEEE Power & Energy Magazine - March/April 2015 - 93
IEEE Power & Energy Magazine - March/April 2015 - 94
IEEE Power & Energy Magazine - March/April 2015 - 95
IEEE Power & Energy Magazine - March/April 2015 - 96
IEEE Power & Energy Magazine - March/April 2015 - Cover3
IEEE Power & Energy Magazine - March/April 2015 - Cover4
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091020
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070820
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050620
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030420
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010220
https://www.nxtbook.com/nxtbooks/pes/powerenergy_111219
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091019
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070819
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050619
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030419
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010219
https://www.nxtbook.com/nxtbooks/pes/powerenergy_111218
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091018
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070818
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050618
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030418
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010218
https://www.nxtbook.com/nxtbooks/pes/powerenergy_111217
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091017
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070817
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050617
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030417
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010217
https://www.nxtbook.com/nxtbooks/pes/powerenergy_111216
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091016
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070816
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050616
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030416
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010216
https://www.nxtbook.com/nxtbooks/ieee/powerenergy_010216
https://www.nxtbook.com/nxtbooks/pes/powerenergy_111215
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091015
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070815
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050615
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030415
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010215
https://www.nxtbook.com/nxtbooks/pes/powerenergy_111214
https://www.nxtbook.com/nxtbooks/pes/powerenergy_091014
https://www.nxtbook.com/nxtbooks/pes/powerenergy_070814
https://www.nxtbook.com/nxtbooks/pes/powerenergy_050614
https://www.nxtbook.com/nxtbooks/pes/powerenergy_030414
https://www.nxtbook.com/nxtbooks/pes/powerenergy_010214
https://www.nxtbookmedia.com