8 February 2014
Renewables won't fix it
Figure 1 - Energy consumption by source. Despite heavy investment, renewables still fail to gain a significant market share.
Many people believe that renewables have the potential to displace fossil fuels. A quick look at historic energy consumption should make it clear that this is very unlikely to happen any time soon (see Fig. 1). 87% of our energy in 2012 came from fossil fuels, 4% from nuclear, 7% hydro, and a measly 2% from other renewables, despite 10 years of rapid growth in solar and wind.
Putting aside any other debate about nuclear power, there is ample evidence to suggest that nuclear cannot scale up significantly in the near future. The cost of construction is extremely high and power stations take at least ten years to build. Even if we did manage to build enough power stations to displace a significant proportion of fossil fuel use, it is unlikely that there would be enough uranium to last very long at that rate .
Hydro power is unlikely to increase significantly, as the majority of major potential hydro sites have already been harnessed. Small scale hydro has some potential, but this is unlikely to make a significant dent in fossil fuel consumption.
Figure 2 - Breakdown of energy sources required to give >60% probability of avoiding 2°C of global warming, assuming 2% growth in total energy consumption, with 10% growth in nuclear (10 year lag), 3% growth in hydro and all other growth coming from other renewables.
The only realistic solution is to scale down our energy consumption, immediately and drastically. This may well crash the economy, but this is likely to happen anyway, due to peak oil. At the end of the day we will find a new economy to fit a new way of living - we've only lived in an economy driven by growth for the last 100 years.
Figure 3 - A more realistic breakdown of energy sources required to give >60% probability of avoiding 2°C of global warming, assuming 2% growth in nuclear (10 year lag), 1% growth in hydro and 5% growth in other renewables.
Many people still cling on to the hope that some new technology is around the corner or being suppressed by oil companies. Even if these technologies do exist, it would take many years to scale up to a significant level. Do we want to gamble our future on technologies that may exist but still haven't come to light, despite our economic and ecological crisis?
Next: How to live sustainably
About the author
Pedro (Pete Brace) graduated from university with a first class honours degree in Computer Science. He then went on to work in the video games industry for 7 years, soon earning a good salary as a Lead Game Programmer, but living an unfulfiling and unsustainable life. In the end he came to his senses and left his job to find a more sustainable life. He is now very happy living as an eco-peasant at Tinkers' Bubble fossil fuel free community in Somerset, UK, where he earns around 97% less than in his old job. 
1. "The end of cheap uranium", Michael Dittmar, Science of The Total Environment, http://www.sciencedirect.com/science/article/pii/S0048969713004579
2. The views in this article do not necessarily represent the views of other members of Tinkers' Bubble