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.