Fermi, on firming the grid: 'Are you all crazy?'

The ready availability online of official Australian data on energy costings and of easily applied AItools allows any reasonably well-informed independent researcher to explore government claims about future costs of a clean renewables-based electricity supply. The results may surprise. It's not hard to imagine the late Enrico Fermi, the world's most famous nuclear scientist and Nobel Prize winner, exclaim on seeing the result – Are you all crazy?

Fermi. Firming. They do sound similar but there's no other connection. Fermi was a famous nuclear scientist. Firming is a way of turning intermittent solar energy into useful clean power. As already suggested it's a fair bet that Fermi would mock such firming. Hence the title of this piece.

Enrico Fermi (1901 to 1954) was an Italian (and naturalized American) physicist, known as "the architect of the nuclear age". He pioneered quantum theory and nuclear physics and in 1938 received the Nobel Prize in Physics. In 1942 he led experiments in Chicago on the first controlled nuclear fission chain reaction. He had a senior role in the Manhattan Project.

"Firming" is technical jargon used by electrical engineers for turning intermittent power sources, like solar and wind, into reliable, continuous supplies for electricity grids. Essentially useless natural bursts of solar or wind energy are fed into the firming system and emerge as a valuable controllable continuous supply. Firming is the key to harnessing commercially the "raw products" of solar and wind farms.

But firming has costs. Energy costs are now so important politically that the government (via AEMO, the Australian Energy Market Operator) regularly commissions and publishes a survey called GenCost, conducted by CSIRO (Australia's leading scientific research organisation), on current costings of a range of generating technologies. GenCost is recognised as a major input to formulating Australia's clean energy policies. It's fair to say that GenCost is not easily digested.

GenCost does not cover nuclear power. I include mention of it here since I have a particular interest in how renewables firming costs might affect perceptions of nuclear energy, which arrives clean and already "firm" from any nuclear power station.

First it must be said that nuclear power has never been allowed here. That position was locked in through legislation in the late 1990s, and nuclear energy is banned by law. One is now used to it. Controversy on the subject is rare and at the political level interest in nuclear power is best described as subdued, or even lower.

Fifteen years ago, there was an extensive academic study called Understanding the Formation of Attitudes to Nuclear Power in Australia (National Academies Forum 2010). A team of eminent sociologists, scientists and engineers sought to clarify how attitudes to nuclear power had evolved here. The study was thorough; in my view it was informative but inconclusive, with little evidence of any subsequent impact. Various bodies have since conducted occasional public opinion surveys, but again there has been little visible in the way of political response, public discussion or government action. The simple reality is that in 2026 nuclear energy remains irrelevant in Australian energy politics. Solar and wind energy overwhelmingly dominate the future outlook, politicians routinely express total confidence in a renewables-based clean energy transition away from fossil fuels, and there are no signs of any impending change in strategy. If the Australian public has an interest in a nuclear future they are keeping it to themselves.

They might have some awareness that nuclear energy is widely used abroad, and a few would know that some 430 nuclear power stations operate worldwide. But they seem not to care. Politicians, and voters, without fear of contradiction, declare "we don't need nuclear".

The mantra gets repeated; renewables are best, renewables are cheapest, renewables are fastest to build, we don't need nuclear. End of story.

Given the strong influence of politics on energy matters I have long held doubts about cost projections made for an illegal operation like generating nuclear power. In any case the available cost projections in GenCost are quite difficult to follow. Now, the recent combination of routinely updated GenCost reports and availability of AI-assisted interpretation and simplification greatly ease the task. It looks like a new study is feasible.

Such a study needs a location. Sydney, Australia's largest city, a major commercial and industrial centre, with population around 5.5 million, seems a good choice. The study should cover generation costs for utility-scale Solar PV (photovoltaic) and wind turbines.

The information here was gathered around the end of January 2026 by direct interrogation of GenCost using ChatGPT. Two costs stood out. Capital cost of a generating system depends on size and electrical load, which need specification. Interestingly, ChatGPT says it cannot specify "a single published figure" for Sydney's maximum load. But it does quote a range as typical, 18 – 23 GW (gigawatts). And it gives a single figure from GenCost of AUD 1.3 million per MW for generating plant installation/construction costs. With these numbers the range of total costs (rounded) becomes AUD 23 – 30 billion. GenCost explicitly excludes some cost components, like "land, grid connections and transmission upgrades". But what it does include is a good start.

Firming is the other major item. It adds to cost but greatly expands utility of a system. According to ChatGPT, lithium-ion batteries "are the mainstream choice today for grid-scale projects". I don't dispute that claim but it does need qualification. Lithium batteries have revolutionised motor cars and portable electrical equipment like tools. Their key advantage is high electrical energy density. But they are expensive and the more mundane performance needs of stationary energy storage should in principle suit cheaper, lower energy density batteries. Clearly the power generation industry values some other benefits lithium batteries offer, like reliability. So, lithium it is.

Two parameters are required to specify firming performance, delivery rate (power capability) and cycle life (how long the charged battery needs to keep supporting the grid). For the Sydney example ChatGPT specifies a power output of 18 – 23 GW for up to 6 hours. This translates to a required storage capacity of up to 108 – 138 GWh, at a cost of $AU 62 – 80 billion. Potential additional costs, like grid connection, inverters, land, project financing, permitting and operating costs, are mentioned but not estimated.

In summary, a utility-scale solar PV-based clean generation system for Greater Sydney, coupled with a lithium battery-based firming system, is costed by GenCost at between $85 billion and $110 billion. The latter figure comprises $30 billion for generation and $80 billion for firming.

These numbers demonstrate the overwhelming effect of firming on cost; at the upper end of cost estimates, firming by batteries represents nearly three-quarters of the total cost $110 billion for a reliable large solar/wind-based power supply suited to a major city.

Who knew? Fermi probably would have. A physicist will appreciate that traditional fuel-driven power sources come with their own storage since fuels by definition are stores of energy. That energy is released as heat on combustion. Hot steam follows, which in the power plant is the medium by which heat energy drives spinning generators.

Solar and wind energy are not fuels. The extra costs of firming they require could turn out to be a dealbreaker, despite the current popularity of renewables. Fermi, a pioneer of clean nuclear energy that needs no firming at all, obviously would have understood this. Which is why I suggest he would have greeted the above calculations and cost figures with "Are you all crazy?"

There's a new case for nuclear energy – it uses a fuel! Time to look at it again.