April 22, 2021


Batteries, solar and wind can easily maintain grid security as coal retires (Dan Cass and Bruce Mountain, 22 April 2021, Renew Economy)

The largest frequency control service in the National Electricity Market (NEM) provides active power to push up frequency for six seconds following a disturbance. In this market, batteries are providing about a third of supply, competing against a coal fleet almost 70 times larger.

Batteries have only been allowed to compete in Frequency Control Ancillary Services markets since 2017. They are already setting the price and eating in to the market share of conventional generators.

A small but growing number of grid-scale batteries are rapidly increasing their share of this NEM frequency control market
A project in northern Queensland changed how the inverters at four large solar farms respond to changes in network voltage and they now provide system strength. The cost of this is was to be around 4% the cost of a conventional synchronous condenser.

Last month the Energy Security Board gave federal and state energy ministers options for redesigning the NEM. Minister Taylor has sat on it since then but is due to be released next week. A critical 'Post-2025' reform is to fix the inertia and system strength rules.

The federal energy minister Angus Taylor can show leadership by calling on the ESB to remove regulatory barriers to batteries, promote innovation and facilitate state energy policies.

The Renewable Energy Zones being built by the states will bring in around 40 GW of generation and many GW of storage. This new energy supply plus a new procurement system for inertia and system strength will allow Australia to rapidly decarbonise our electricity system securely.

The current system misallocates risk to renewable energy projects. The 'do no harm' principle forces them to pay for system strength weakness that they are not responsible for. The 'causer pays' principle penalises them for variability of solar and wind output that they are not responsible for.

Ultimately, inertia and system strength are both public goods and should be procured efficiently on behalf of all consumers.

Posted by at April 22, 2021 12:00 AM