IEEE Power & Energy Magazine - May/June 2014 - 73

australia, killing 35 people and resulting in an estimated
a$30-billion loss to the australian economy (see Figure 11).
the floods covered three quarters of the state, an area larger
than France and Germany combined. Parts of Brisbane,
Queensland's capital city, were flooded, and electric power
was cut off to many areas due to safety concerns. this
resulted in some situations where properties were cut off,
despite not being inundated, because the arrangement of network feeders did not coincide with the areas flooded. this
leads to three issues relevant to microgrids: islanding, protection, and education.
During the floods, the residents in Brisbane were advised
to consider all facilities as electrically live and to contact
licensed technicians for the safe restoration of electric supply
to damaged property. in the event of risk due to inundation,
islanding is necessary. Due to rising waters, some residents
climbed onto the roof of their property to escape while waiting for assistance. this led to risks where rooftop PV systems were installed, and residents were warned to treat solar
panels and accessory equipment as electrically live. Further,
the residents were also advised that solar PV systems were
designed to shut off when the main grid was down. residents
were urged to avoid touching any part of the systems, including disconnecting individual panels to run small appliances
or charge batteries. some residents expected that having a
PV system would mean that in the event of a natural disaster,
such as these floods, they would have a secure source of electricity. unfortunately, such systems are designed to operate in
grid-tied mode only so they cannot be used during grid outages. the same issue has been observed during several recent
hurricanes, such as hurricane isaac in the lower ninth ward
of new orleans, louisiana, a neighborhood rebuilt as a sustainable community after it was destroyed during hurricane
Katrina. one might observe that there is no technical barrier
to making a PV system able to continue to provide local supply without the presence of a wider grid, and, even if resynchronization cannot be done automatically, a manual switch
system would suffice to change between grid connect and
island mode. in fact, such a system is employed in countries
where the power supply is not very reliable. For example,
many government buildings in india have standby generators
that can be started, and the two-way switch system is used.
the Queensland floods raised several issues in relation
to microgrids. First, it seems that microgrids were already
in existence but were not designed to transition to island
operation. in fact, they were designed to detect unintentional
islanding and simply shut down. while there is certainly
an associated safety issue, there may be more sophisticated
approaches that can be taken. this brings up the question
of whether the barriers to this smarter behavior are related
to costs or regulatory policies. second, it raises the question of whether microgrids that allow "ride through" are
smart enough to automatically detect conditions associated
with a disaster and therefore be able to continue operation
or shut down as required. third, residents were judged to be
may/june 2014

figure 10. Mississippi Power's portable diesel generator
after Hurricane Katrina. (Source: A. Kwasinski.)

figure 11. Floods in Queensland, Australia. (Courtesy:
Timothy Swinson, Flickr-kingbob86.)

figure 12. Damage to distribution poles from the 2007
forest fires in Greece. (Courtesy: PPC, Greece.)

unaware of the capabilities and the risks of rooftop solar PV
systems during a disaster, creating an issue of education that
should be explored.

Forest Fires in Greece
During 24 august-2 september 2007, forest fires erupted
in Peloponnese and evia in Greece, affecting more than
400 villages with 1,500 houses completely burnt and 6,000
people left homeless. the forest fires also caused extensive
damages to the medium-voltage distribution network, including
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