One cannot but be impressed with the work of Greene and his students, not just at winning the Queen Elizabeth Prize for Engineering, but for the 40% improvement in the efficiency of solar cells that resulted from the application of their work. The report may be read here: https://www.bbc.co.uk/news/science-environment-64553915 (Queen Elizabeth Prize: Solar team wins prestigious engineering award)
We are also provided with an impressive graph which appears to show that in 2021 solar production of electricity was nearly 50% of that provided by coal. Closer inspection reveals that not all is well with this graph. The percentages do not add up to 100. Something is missing, and most of the missingness can be filled by oil and nuclear, nearly 14% in 2010 falling to 10% in 2021. I am aware that the graph runs to 2022, but I have to restrict my comments to 2021 not having additional data for 2022.
The second problem we have is that it does not take into account the increase in consumption of electricity since 2010. In 2010 total production was roughly 21TWh, increasing by 25% to 28TWh in 2021. The graph shows nice falling lines for coal and natural gas, which are of course big carbon dioxide producers, as if we are reducing our dependence upon them. If we apply the 25% increase in consumption to the graph however all of the lines tend upwards.
The real problem however is that we appear to be looking solely at electricity consumption. This rather distorts the issues, giving a false impression of how well we are doing in our progress towards the combat of the factors that influence unwanted climate change. A different analysis can be seen if we look not only at electricity consumption, but at the energy costs of electricity production. Coal then comes in at 36%, solar at only 4%. For coal you get out in electricity about one third of what you put in. When you factor in other uses of power, such as transport (shipping, petrol and diesel vehicles, etc) then the picture yet quite different as you may see in the graph below.
Given that the figures behind this have been compiled by BP if there is any bias in them at all it is likely to be in favour of fossil fuels, rather than the other way round, but I have assumed there is no bias. Solar costs are about 3TWh for 2021. Coal is about 44TWh. There is quite a good discussion on https://ourworldindata.org/electricity-mix explaining why we need to look at the production costs of the power we use not just at the power we consume.
The good news is that renewables, which consisted of only 14% of total energy use in 2010 in 2021 consisted of 17%, and increase of 45%. This mitigated the increase in fossil fuel use, but we still managed to increase out consumption of fossil fuels by 12%.
Let me add in closing that the BBC graph is accurate. It describes precisely what it claims to describe. It could make a nice marketing tool for an electricity supply company that wanted its customers to feel good about buying from them, but it does not provide the information we need to assess where we are in our efforts to decarbonise energy production.
| Summary figures: | TWh | TWh | |
| World | 2010 | 2021 | |
| Fossil fuels | 121480 | 136018 | 112% |
| Other sources | 19019 | 27691 | 146% |
| Total | 140500 | 163709 | 117% |
| Fossil fuels | 86% | 83% | |
| Other sources | 14% | 17% |