A large number of Australia’s bush fires are caused by failing, or falling, electricity assets.   The 2009 Victorian Bushfires Royal Commission noted the expense involved in reducing the risk of fire, including putting electricity supply lines underground, but said (Final Report, Volume II, p  149):

… the seriousness of the risk and the need to protect human life are imperatives the Commission cannot ignore. The number of fire starts involving electricity assets remains unacceptably high—at more than 200 starts recorded each year.

The Commission made a number of recommendations to deal with fires caused by electricity assets including recommendation 32:

The State (through Energy Safe Victoria) require distribution businesses to do the following:

  • disable the reclose function on the automatic circuit reclosers on all SWER lines for the six weeks of greatest risk in every fire season
  • adjust the reclose function on the automatic circuit reclosers on all 22-kilovolt feeders on all total fire ban days to permit only one reclose attempt before lockout.

This recommendation would decrease the reliability of electricity supply as transient faults would cause power to be disconnected until the system could be manually checked, unlike the system in place in 2009 which allowed for the circuit breakers to ‘close’ up to 3 times before locking out.  This meant if there was a fault, the power was disconnected then reconnected to see if the fault had cleared.  If the fault recurred three times then power was shut off until manually checked.  The system increased reliability but also the risk that the electricity assets would cause a fire.  With respect to their recommendation, the Royal Commission said (at p 172):

To the extent that there is a decrease in the reliability of supply to SWER line customers, there is a corresponding benefit to those same customers in that the likelihood of fire starting in their area will be reduced.

Aware of the risk posed by electrical supply assets, the South Australian power supply company, ETSA disconnected the power supply on a particularly bad fire weather day in January 2012 (see ‘Power cuts as state endures scorcher’ ABC News, 2 January 2012; ‘ETSA defends decision to cut power’ ABC News, 3 January 2012).  An ETSA spokesperson is quoted as saying:

“We recognise there is inconvenience but we recognise that at the end of the day we have a responsibility under the legislation to make these decisions and we have to make them in real time in emerging circumstances to protect lives and property.”

He says the decision to cut power was the right one.

“I doubt we can said to be negligent in this, we’ve followed our procedures. We have a legislated authority to turn-off power. We’re required to do that.

“We made a decision on the basis of localised conditions where the CFS had seen fire conditions escalate.”

ETSA and the other electrical authorities may think they are doing the right thing, but research published in the Medical Journal of Australia now paints a different picture.  In their article ‘The definite health risks from cutting power outweigh possible bushfire prevention benefits’ (197(8) Medical Journal of Australia 440-441 (15 October 2012)) Richard Broome and Wayne Smith report on their study of the likely public health effects of cutting off the power.    They say:

The 2009 Victorian Bushfires Royal Commission heard that about 1%–4% of all bushfires are caused by electrical faults and that this proportion rises on days when catastrophic fires have occurred.  Switching off the power supply will, therefore, prevent a small proportion of fires. On the other hand, a functioning power supply has many health and safety benefits that may be particularly important on days of high fire danger.

Cutting off the power can affect people’s ability to receive warnings as they can’t operate televisions and computers, can cause failure of traffic signals increasing the risk of accidents, may cause garage doors to fail leaving people trapped and may affect fire fighting efforts by restricting the supply of water.   Cutting off power may also increase the risk from other ignition sources such as cooking fires and home generators.   They also say

An important omission from the health and safety arguments …  is a discussion of the role of air conditioning in preventing heat-related illness. Days of high fire danger are generally very hot and therefore likely to be associated with high rates of heat-related morbidity and mortality. For example, the Victorian government estimated that the 7-day heatwave preceding the February 2009 bushfires caused 374 deaths, a 62% increase above the baseline mortality rate…

The estimate of the protective effect of home air conditioning may be applied to the 2009 Victorian heatwave. If we assume that power was cut for the full 7 days, accounting for the fact that many residents were without power because of load shedding for up to 2 hours on 29–30 January 2009, there would have been an additional 192 heat-related deaths. While this is an extreme example, it serves to illustrate the point that cutting power during a heatwave can have enormous consequences. If, as is more likely, power was cut for just a single day, there would have been an additional 28 deaths…

Deaths from heat outweigh direct deaths from catastrophic bushfires, with Australia’s most catastrophic bushfire tolls (Black Saturday in 2009 and Ash Wednesday in 1983) resulting in 173 and 75 deaths, respectively. So from a public health perspective, power cuts are more likely to lead to adverse health outcomes than maintaining power on potentially catastrophic bushfire days…

[I]t is our view that power should never be deliberately cut off, except to an area that has already been evacuated.

These findings may well cause a concern from the electricity authorities who may be concerned that they will be condemned no matter what they do.   The public health issues were not fully canvassed in the Victorian Bushfires Royal Commission as the Commission’s terms of reference required it to look at the fires and how to prevent fires, not how to maximise public health.  It is well know that more people died in the preceding heat wave than the black Saturday fires but that has not attracted the sort of attention that the fires did, so it is understandable that the electrical authorities are more concerned about taking steps to prevent fire and in particular, to stop them being sued for the start of fire; the other broader public health issues have not been the subject of such direct focus.

It is questionable however, whether all the ramifications suggested by Broome and Smith are inevitable or should be considered the ‘trump’ card.  Australia’s national policy is to build resilient communities that share responsibility for emergency management and the various agencies go to great lengths to encourage people to plan for events, and to recognise that even if power is not cut off by the supply authority it will be cut off by the fire.  People are encouraged to have their home emergency kit complete with battery operated radio so they can still access information; a resilient community, and a sensible driver, should be able to cope with traffic lights that have turned off, and people should know how to open their garage door if the power is off.   If people are vulnerable, because of their age, ill health or infirmity, then the agencies would encourage them to leave areas of danger on catastrophic fire days so if that means making their way to facilities that have back up power, or out of the area all together so be it.  If they remain and a fire comes they are going to be unable to evacuate, or be evacuated, in any event.

The findings of Broome and Smith may be true if people who live in fire prone areas fail to prepare and assume that the power will always be on and that they can stay in their home until evacuate by the fire service.  They are not true if, as a community and as individuals, people have prepared themselves and if necessary, made preparations to provide for their vulnerable family members, and accept that in an imperfect world, sometimes the power will go off when you least want it to.   The authors may suggest that ‘power should never be deliberately cut off, except to an area that has already been evacuated’ but fail to consider that the alternative is that the power will only be cut off to an area that is threatened by fire in which case it’s too late.   People whose family members are lost to bushfire are unlikely to be sympathetic to the claim ‘but we had to leave the power on so the air conditioners would work and it was only a small chance that there would be a fire’.  The answer is not to keep the power on except to evacuated areas, the answer is to convince communities that on extreme fire days, all the utilities, power, water, telephone etc may fail and that is why they need to be prepared, resilient and to have worked out what they are going to do to protect themselves in those circumstances.

Michael Eburn

19 October.