A state-owned power utility has been fined after it cut electricity supply to 20 people on life support systems without warning, it has been revealed — the latest in a track record of over a dozen similar breaches since 2014.

Key points: Three planned outages by TasNetworks between August and November 2018 affected 20 people, the energy regulator said

Three planned outages by TasNetworks between August and November 2018 affected 20 people, the energy regulator said The company was fined a total of $60,000 for not sufficiently notifying those affected — a situation that "must not be repeated", the regulator said

The company was fined a total of $60,000 for not sufficiently notifying those affected — a situation that "must not be repeated", the regulator said Between 2014 and 2018, AER issued 13 separate infringement notices to TasNetworks for power cuts to people on life support, each attracting a fine of $20,000

Tasmania's utility TasNetworks paid three infringement notices totalling $60,000 and "signed a court-enforceable undertaking to address deficiencies in the way it manages its planned interruptions, particularly those affecting life support customers" following action taken by the Australian Energy Regulator (AER).

In a statement, the AER said TasNetworks conducted "three planned interruptions to supply without providing affected life support customers with four business days' written notification" between August 2018 and November 2018 — a situation it said "must not be repeated".

"People who rely on life support equipment should expect their distributor will provide them with the legally required notice to planned interruptions to their supply," AER chair Clare Savage said.

"Robust enforcement ensuring compliance with the law is vital in building consumer trust that businesses are doing the right thing," she said.

The first planned interruption "affected one life support customer, the second 18 and the third another customer", AER said, without detailing the nature of the impact to those affected.

Ms Savage said she was "encouraged that TasNetworks has agreed to provide a comprehensive court-enforceable undertaking outlining the steps they'll take to ensure this doesn't happen again".

Track record of fines for similar breaches

The AER database shows that between June 2014 and November 2018, TasNetworks was issued 13 separate infringement notices over "incidents where customers known to require life support equipment unexpectedly lost electricity supply".

Some outages affected multiple premises, while the details of other outages are unclear as to how many customers lost power — or whether the same customers experienced repeated cuts to their supply.

An infringement notice for an outage on August 7, 2018 was for a loss of power that lasted for over seven hours.

Each infringement notice attracted a penalty of $20,000.

Following the latest outages, AER said the court-enforceable undertaking required TasNetworks to:

Engage an independent expert to complete a post-implementation review of systems and processes it has implemented in response to a previous audit of its life support processes;

Engage an independent expert to complete a post-implementation review of systems and processes it has implemented in response to a previous audit of its life support processes; Implement a project to verify the low voltage network connectivity of each of its existing life support customers; and

Implement a project to verify the low voltage network connectivity of each of its existing life support customers; and Implement a system upgrade that will assist in identifying areas that will be impacted by planned interruptions.

'We've learned' from previous fines, company says

The AER said it was "committed to protecting vulnerable customers as part of its robust compliance and enforcement strategy," Ms Savage said.

"The AER takes life support matters very seriously. The protections in place for vulnerable customers such as these are the law and we will enforce the law when it is breached.

"Every other business dealing with life support customers should consider themselves on notice," she said.

In a statement, a TasNetworks spokesperson said "life-support customers are a crucial priority" and "we've learned from previous notification breaches".

"We're reviewing our contact process, introducing new rules, and educating employees to improve performance," the spokesperson said.