Georgia on my mind

A new, large-scale, water-cooled nuclear reactor has just come on line in Georgia, USA.

It took years longer to build than initially planned. This one (Plant Vogtle Unit 4), and its predecessor (Plant Vogtle Unit 3) that came online in the northern summer of 2023, together are estimated to have cost nearly US$35,000 million. That's about A$53,000 million.

One report claimed: 'The carbon-free power comes at a high price.' Compared with what?

These nuclear plants are expected to generate always-on power for over 500,000 homes and businesses for over 80 years. Compare that with renewables' plant lives. Solar panels last up to 30 years. Wind turbines last about 20 years. Battery storage lasts 10-20 years.

Comparing costs for all of these energy sources should be over the same period – 80 years.

For solar panels, installing brand-new capacity would be needed 3 times over 80 years.

For wind turbines, installing brand-new capacity would be needed 4 times over 80 years.

For battery storage, brand-new batteries would be needed 4 – 8 times over 80 years.

The repeat renewables investments sit on top of the large year-one renewable capacity needed to ensure reliable, always-on, power each day. This capacity itself is smoothed daily generation plus storage capacity averages. It ignores big weather fluctuations around those averages.

Solar power, on average, is 'full-on' about 15% of the day, and off for 85% of the day.

Wind power, on average, is 'full-on' about 30% of the day, and off for 70% of the day.

Battery storage is a big problem all by itself. Consider this. The NEM last financial year supplied over 520,000mwh of power per day. Battery storage, based on Hornsdale SA's 'big battery' capacity of 194mwh from one full charge, means over 2,000 Hornsdales are needed, averaged across solar and wind, as renewables back-up for the NEM.

Over 80 years, in place of Georgia-type nuclear power plants, three lots of solar generation capacity must be about 20 times as large. Four lots of wind generation capacity must be about 13.3 times as large. Battery capacity must be at least 8,000 – 16,000 Hornsdale 'big batteries'.

These large numbers are minimal estimates of needed renewable energy capacity to match large-scale nuclear power plants delivering the same power and reliability, 24/7, for 80 years.

What will that renewables capacity cost? Those promising zero net emissions should tell us.

Transparent policy answers should be evidence-based, not political assertions.

It's said the Hornsdale SA 'big battery' cost A$90 million. To 'keep the lights on' in the NEM each day, averaged over the year, 2,000 Hornsdales would cost $180,000 million. Over 80 years, allowing for 8,000 – 16,000 Hornsdales, that's A$720,000 million - A$1,440,000 million.

That's just for the batteries. Generation and transmission are extra. Nuclear looks cheaper.

Will solar, turbine, and battery storage costs collapse? If so, who can compete supplying them?

Will renewables have more emissions over their full renewables asset cycle than nuclear?

It would be nice to get some answers. Based on objective evidence, not mere assertion.