IEEE Power & Energy Magazine - March/April 2015 - 96

in my view

Iain MacGill and Anna Bruce

photovoltaics in Australia
time for a rethink

the capacity of installed
photovoltaics (pVs) in australia has
expanded from around 50 MW to 4 GW
over the past five years, an 80-fold
increase. this has been driven by a
perfect storm (or perhaps perfect rainbow) of rising retail electricity prices,
falling global pV module prices, a
strong australian dollar, and federal
and state government support. indeed,
australian policy makers have widely
agreed that pVs have become "too
successful," and almost all state government support was removed several
years ago. still, growing public acceptance of the technology, continuing
capital cost subsidies under the federal
Renewable energy target, and deployment-driven cost reductions have seen
more than 800 MW deployed over the
past year, according to the australian
clean energy Regulator.

A Household Affair
While per-capita pV capacity in australia remains well below that of some
other countries such as Germany and
italy, australia's pV market is notable in
that almost all of this 4-GW capacity is
deployed as residential pV systems typically 1.5-6 kW in size (see figure 1).
this outcome reflects a range of factors,
including the targeted nature of pV support policy to date toward households,
but also the high retail electricity tariffs they pay, among the highest in the
world on an exchange rate basis. Given
that household pV systems can now
Digital Object Identifier 10.1109/MPE.2014.2380575
Date of publication: 24 February 2015

ieee power & energy magazine

be purchased at prices below aU$2/W
(Us$1.60/W) installed (indeed as low
as aUs$1/W after capital subsidy),
they can represent an excellent financial
investment, depending on household
electricity demand and its match to the
pV generation profile. this is because
the great majority of residential pV
systems in australia are net metered
so that pV generation offsetting that
household's electricity demand "earns"
the retail tariff (around Us$0.24/kWh).
By comparison, with net metering in
much of the United states, however,
pV exports at times when generation is
greater than household demand are typically paid around a quarter of this retail
electricity tariff (Us$0.06/kWh).
in the australian national electricity market (neM), around one in seven
dwellings has a pV system installed. in
the sunny states of south australia and
Queensland (representing in total around
27% of australia's population), the installation rate is around 25% of households.
it is estimated that pVs met more than
1.6% of total load (and perhaps 7% of
residential load) in the neM in 2013. pV
generation has also approached instantaneous penetrations of 10% of total neM
demand (more than 25% in south australia) on some sunny afternoons.

Technical Challenges and
Revenue Problems for
Australian Distribution
Network Businesses
the challenge of appropriately integrating all of this household pV falls,
first, upon the australian distribution
network service providers (dnsps). in

the neM, these are economically regulated monopoly wires businesses, quite
separate from the retailers who buy
power from the wholesale electricity
market to on-sell to energy end-users
in the retail market.
Virtually all australian household pV
systems have single-phase inverters connected to the low-voltage (230 V) network. the dnsps will inevitably have
areas of their network with greater than
average pV penetrations due to factors
including suitable stand-alone housing
stock and household demographics. the
australian pV institute and centre for
energy and environmental Markets at the
University of new south Wales recently
undertook a survey of dnsps regarding technical issues arising from these
emerging high pV penetration areas. the
respondents, collectively serving around
70% of australian electricity customers, identified a range of technical issues
associated with high penetrations of pVs
that they were experiencing or anticipating. they were also questioned regarding their management responses, present
and proposed, toward addressing these
impacts. the most prevalent challenges
identified were with voltage regulation
and phase imbalance. despite some concerns about pV system islanding, there
was no clear evidence of this happening
in practice, while periods of minor reverse
power flow generally didn't cause any
material network operation problems,
and the pV system inverters were not producing significant harmonics or causing
power factor issues.
(continued on p. 92)
march/april 2015

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