• The general Australian power price has risen over the 40 years at twice the rate of inflation with prices really taking off in 2007, coincident with increased renewable energy target.
  • SA has the most expensive power of any of the mainland States.

Chris Morris is a semi-retired power station engineer in New Zealand who has commented here on No Minister occasionally and on other NZ blogs. In mid 2023 he emailed me about a series of four articles he had written for the blog of Judith Curry in Australia and it is to my shame that I’m only just getting around to this now.

But given some of the articles I’ve written here about Renewable Energy and given the likelihood of us paying more than $30 billion for carbon credits when we exceed our 2030 GHG emission targets I figure I should get Chris’s stuff up for another view by people in NZ.

Now the first three articles are all about the Australian’s desperate effort to transition their entire power system to renewable energy, but he does have a fourth one dealing with New Zealand because we’re already almost there thanks to all our hydro. Check out the Transpower live data which updates the entire NZ situation every few minutes. We are almost never under 90% renewable energy production.

I’ll summarise each part, so here’s Australian renewables integration: Part 1, but do read the whole thing (the State network maps are cool). Part 1 basically just sets the scene:

  • 80% of Australians live within 30 miles of the coast and a larger percentage in urban areas, which are big cities around the continental edge.
  • The system was heavily reliant on large coal-fired power stations that fed the cities via transmission lines.
  • Each of which originally ran their own electricity system. Each State has a transmission grid company that owns and operates their high voltage network. There are distribution companies for the low voltage networks that have territories for which they are responsible.
  • Very little interconnection, backed by a very parochial political system between states (6 states and several Territories), and while there are now State interconnectors they often act more as chokepoints.
  • In the 90s, the National Electricity Market (NEM) was started up to try and tie all this together, but even then Western Australia (about 1/3 of the nation) is not part of it. There are several components:
    • Energy Regulator at the top: enforces the rules, arbitrator of disputes.
    • Australian Energy Market Commission (AEMC): make and amend the rules (but can’t propose them).
    • Australian Energy Market Operator (AEMO) operates the system and does the forecasts.
  • Lots of bureaucracy as a result.
  • The system runs on merit order dispatch (read the details at Chris’s link). There are special rules around bids by wind and solar power stations. Most generators are private.
  • There are many electricity retailers, some generator-based themselves, most connected to generators via long-term contracts but some who run on the spot market prices with backup hedges for their load requirements.
  • The backbone of the system is still coal (60%).
  • Renewables are subsidised to varying extents.
  • The general Australian power price has risen over the 40 years at twice the rate of inflation with prices really taking off in 2007, coincident with increased renewable energy target.

He takes a brief look at renewable energy in South Australia:

  • The intermitancy of wind and solar means there have to be duplicate power generators that can ramp up quickly.
  • The mainstay 400MW+ coal units that form the background of the energy supply can take three days to get to full load if cold, so gas plants are one part of the answer
  • Interconnection to Victoria is the other part: l. In the right conditions, up to 40% of the State’s load come in through its lines.
  • All this means the cost bounces around a lot.
  • Matching load and generation generally takes a very fine balance backed up by a lot of very expensive plant infrastructure. 
  • As a result SA has the most expensive power of any of the mainland States in the NEM.