Clean energy: the state of play

C. 700% renewables would take 208 years.

Higher growth rates seem necessary. A threefold increase to 93 PJ per annum has the outputs reaching goals in 8, 28 and 69 years respectively. A tenfold increase to 310 PJ per annum reduces those periods to 2.3, 8.5 and 21 years.

These illustrative calculations show that present near-record growth rates would be much too low to meet stated ambitions within practical time scales. Growth would need to be between three and ten times faster. Calculations of this kind can be repeated for any chosen set of data. Expressing targets and growth rates as energy quantities is the key to valid calculations.

Net Zero Emissions

"Net Zero Emissions" is the new clean goal sweeping the world. It equates roughly to the above 300% goal for clean energy but also includes a separate provision for removing some existing CO₂ content from the atmosphere. That's where "net" comes in. Apart from planting more trees and raising soil organic matter (biomass) content, the required removal technologies are generally not specified and do not now exist. A target date of 2050 is often mentioned.

Australia seems ready to sign up to NZE despite lack of pathways and costs. The politics demands expression of intent; feasibility can wait. But it's certain that an NZE target will require generation of at least "300% renewables" and growth rates three to ten times higher than now.

Will renewables be enough?

Will a clean energy strategy confined to renewables do the job of reaching distant targets?

Australia's clean energy options are restricted by its nuclear energy ban. Nuclear energy was once simply feared. Now it is routinely dismissed as "too slow, too expensive". With an emerging need for faster growth of clean electricity, that objection must now be thoroughly examined.

On renewables costs, published industry data indicate that over the last 8 years at least $20 billion was spent on the solar and wind assets that in 2020 generated 167 PJ clean electricity per annum. Compare that with targets in the range of 2900 to 6700 PJ per annum being contemplated. The quoted expenditure contained no provision for making intermittent sources reliable through storage, etc. It is not the full cost of a reliable renewables-based electricity supply customers reasonably expect.

How much would nuclear energy cost? What time scale is required? How do those figures compare with solar and wind energy when costs include backup and periodic replacement of solar panels and wind turbines?

Costs are a big subject. Present claims regarding nuclear costs seem to rely on government inquiries and consultant reports. This is a naïve approach. My view is that the commercial costs for an illegal technology cannot be obtained by those means. At the very least tenders and quotations that involve the energy and nuclear construction industries are essential.

Objections to nuclear energy on grounds of cost and time taken cannot properly be tested while nuclear energy remains illegal. Until the ban is removed, the cost of nuclear energy in Australia is best regarded as an unknown quantity. When that is corrected Australia can decide how best to proceed towards its clean energy future.