Renew Extra Weekly

An arguably definitive study of new advanced non-water cooled nuclear options, including molten salt reactors and liquid sodium cooled fast reactors, from the US Union of Concerned Scientists, concludes that none can be ready for at least a decade, more like two, and there are none that meet safety, security, sustainability criteria, apart possibly from once-through breed and burn reactors. If we want nuclear it says it would more sensible just to upgrade the standard, more familiar, water cooled reactors. It sets the scene by noting that, in the United States, so-called Light Water Reactors (PWRs and BWRs) have dominated, these using ordinary water to cool their hot, highly radioactive cores, as opposed to reactors like the Canadian CANDU that use ‘heavy water’, with a double neutron hydrogen isotope, as a moderator. Support for LWRs has continued, despite some economic problems, which have bedevilled expansion in the US and elsewhere: ‘new nuclear plants have proven prohibitively ex...

The battle over energy options continues, with one issue being the scale, pace and focus of the technological innovation needed to cut emissions. The International Energy Agency says that: ‘Almost half of the emissions reductions needed to reach net zero by 2050 will need to come from technologies that have not reached the market today.’ So there is a need to push new technology and support technology innovation.  That certainly is the line adopted by Bill Gates in his new book ‘How to Avoid a Climate Disaster: The Solutions We Have and the Breakthroughs We Need’. He sees solar and wind doing quite well, but thinks their variability could lead to problems. So he says new energy options are also needed, including for sectors other than just power. So he is keen on large scale carbon removal technology, and a range other technical fixes, and he seems especially keen on high tech nuclear- Small Modular Reactors and fusion.  That of course is also the message coming from parts of...

Depending on how you do the sums, in most assessments, in direct Levelised Cost of Energy terms, nuclear comes out as far more expensive than any other energy option. For example, the US National Renewable Energy Research Labs have put the cost of nuclear at about $163/MWh and wind and solar at around £40/MWh, these figures being mid range of the 2020 data from Lazard . And as their costs continue to fall, wind and solar win against all the others. But these are just the direct costs. A study by Sovacool et al adds in estimates for the additional so called ‘external’ social and environmental costs. On that basis, wind still wins overall, and does better than solar PV, but nuclear is over-taken by coal as the worst option. The rest fall somewhere in between.  Some other assessments differ in terms of safety and impact rankings, and certainly estimating social and environmental costs is not easy, especially for future costs. And even past costs! We are still battling it out over the ...

 In search of net zero emissions some pretty odd ideas can sometimes be promoted. A post from the contrarian Saltbush group in Australia offered this pejorative list , mostly related to carbon removal options:  1. Buy dodgy carbon credits from dubious foreigners. 2. Cover our grasslands and open forests with carbon-absorbing bushfire-prone eucalypt weeds. 3. Build costly energy-hungry carbon-capture schemes. 4. Chase the hydrogen mirage. 5. Log and replant old-growth forests. New trees will grow and extract CO2 faster than old mature trees.  Leaving the slightly hectoring tone aside, there are some valid points here. Carbon credits are sometimes rewarded for poorly regulated carbon sequestration and offset activities, including bio-sequestration. Direct Air Capture is very energy intensive and, like reliance on biomass/trees to absorb CO2, opens a range of environmental and land use issues – notably, is there enough room to safely store all the CO2 we would need to trap...