Energy minister Angus Taylor has written to the Australian Energy Market Commission to ask for a change to the National Electricity Rules to extend the notice period from 3.5 years to a minimum of five years.

He said this was a critical reform to ensure the energy sector had enough time to replace existing capacity, with the lead time required to construct most forms of new generation far exceeding the 3.5 year notice period.

"The government is committed to ensuring ongoing reliable and affordable energy," Taylor said.

"This means it is critical to ensure there is a pipeline of projects that can be delivered to replace existing capacity, keep the system reliable and secure, and keep power prices down for Australian households, businesses and industry.

"If accepted, the rule change will increase notice of closure requirements to five years to allow adequate lead time for new capacity to be built to replace exiting generation, and to prevent potential gaming of notice of closure requirements by market participants.

"This is a sensible change, and necessary to ensure the National Electricity Market remains reliable and secure."

Taylor said without this rule change there was a risk that retiring capacity was not replaced in time or only able to be replaced with inadequate or inefficient options that were available in short timeframes, risking the reliability, affordability and security of the system.

The proposed rule also includes a definition of "longer term mothballing", within notice of closure arrangements.

A longer term mothballed plant is to be defined as a generator that will be unable to dispatch for nine months or longer over a 12-month period.

These generators would be subject to the same notice period that applies to permanent closures, to avoid potential gaming where generators could mothball a plant indefinitely without providing any notice or date of an intended closure.

Seasonal mothballing, defined as a generator not being available to dispatch electricity into the NEM for fewer than nine months over any 12 month period, would not be subject to notice of closure requirements.

The rule would also prohibit speculative notices of closure when the generator has no actual intention to close the plant on the specified date.

"This rule is intended to prevent generators from engaging in behaviour that could create uncertainty in the market and act as a deterrent to new investment," Taylor said.

Under the proposed rule, the Australian Energy Regulator will investigate any notice that it suspects to be speculative, using its existing investigative and information gathering powers.

Australia Institute climate and energy program director Richie Merzian described Taylor's statement as "kneejerk".

"Minister Taylor must be suffering from a bit of FOMO [fear of missing out] with plant closure deals being stitched up behind his back," he said.

"It raises eyebrows that a government so resistant to planning a roadmap for Australia's coal closures is now apparently so keen for longer plant closure notice periods.

 "It is abundantly clear that coal plants are going to accelerate their closures, closing faster than their official retirement dates.

"If this government was genuine about providing certainty to coal communities, it would develop a national coal closure roadmap rather than attempting to strong-arm coal plants one by one."