All is not well with the clean energy transition. At this stage positive commentary on the transition is dangerous. 2017 saw a 2% rise in global carbon emissions, with the concentration of CO2 passing 400 ppm for the first time in several million years.
The motivation for the clean energy transition is to reduce the damage of climate change. But the threat of violent climate change doesn’t allow us to ignore historical truths.
This post highlights four reasons why progress of the clean energy transition is slow. All four reflect the experience of previous transitions. All four are unwelcome.
I’m not arguing against the need for the clean energy transition. I’m trying to show that history suggests this transition will continue to be slow and difficult.
The primary source for these ideas is Vaclav Smil’s excellent work on energy transitions (book, lecture and another lecture). Smil is my favorite energy writer; prolific, confidentially numeric and intelligently contrarian. Smil’s work is for me the best on energy ever written. I’ve also previously written about Smil’s work on carbon capture and storage.
The Four Inconvenient Truths of Energy Transitions
Energy transitions drive the development of civilization. Muscle and wood powered our early days; today we use coal and gas to drive turbines, oil to enable global transportation and can harness the nuclear energy of celestial bodies. Now we are moving toward clean and smart technologies; wind turbines, solar panels, energy storage and data driven optimization.
This transition is simultaneously similar and different to past transitions. This post will highlight four truths about energy transitions.
Three ways in which this transition is similar to the past
And one in which the clean energy transition is departing from previous transitions - enabling new utility
The First Inconvenient Truth - Energy transitions are slow
In Energy Transitions: History, Requirements, Prospects, Vaclav Smil notes each subsequent transition takes longer than the last. To move from 5% to 25% of global primary energy consumption, coal took 35 years, oil 40 years and finally natural gas took 55 years.
There are two reasons for the slowing down. As the absolute size of our energy consumption increases, the relative effect of adding more is smaller. The massive growth in global energy consumption means that effort today has a smaller relative effect than in the past.
Second, technical challenges increase. Moving from wood to coal was an easy transition - both are solid fuels that can be transported, handled and burnt using similar techniques. Using oil required building a massive global upstream and downstream infrastructure, cars and roads to drive on. Gas turbines and nuclear power are some of the most complex machines ever built.
The clean energy transition is full of technical challenges. Clean energy generation is low power density (W/m2), meaning we need to build wind & solar across vast areas of land. It also requires transmission lines, energy storage and intelligent operation, to counteract the disadvantages of geographically dispersed, low capacity factor and intermittent renewables.
What this means for the clean energy transition - it’s going to take a long time.
The Second Inconvenient Truth - Energy transitions are additive
This is the most inconvenient of the four truths. Each transition increases the amount and quality of energy we use. But each time we transition we don’t replace old energy sources - we add new energy sources on top. Older fuels take a long time to go away. We are still building coal-fired generation today and are recklessly likely to for a long time.
Figure 1 shows the history of US primary fuel consumption. US coal consumption has risen all the way through to the start of the 21st century. Each new fuel has not displaced coal, instead they add to an existing and increasing coal consumption.
Figure 1 - U.S. Primary Energy Use over time in Quads from 1800 to the present by source - US Department of Energy Quadrennial Technology Review 2015
Renewables already make up a significant part of generation we are building to supply our increased energy demand. But it’s the older fossil fuel generation that also need to be cleaned up - history shows us this doesn’t happen quickly.
Improvements in technology, building of supply chains and know-how mean that mature technologies are often efficient, cheap to build and cheap to maintain. Having a track record of economic performance also makes older technologies more attractive to investors.
Diesel generators (an 1890’s technology) are a great example of this. Diesel generators are reasonably efficient, quick and cheap to build with a well-understood maintenance schedule. They continue to be built on the kW to multi MW scales.
What this means for the clean energy transition - fossil fuels aren’t going away.
The Third Inconvenient Truth - Energy transitions are sequential and high variance
Smil notes that energy transitions require a “specific sequence of scientific advances, technical innovations and organizational actions” combined with “economic, political and strategic circumstances”.
The dependence on doing the right things in the right order means progress is not guaranteed. Variance in causes in conditions combined with path dependency creates different energy systems all around the world. Coal dominated China, nuclear powered France and hydro blessed New Zealand show that energy systems are not homogeneous.
Don’t confuse the inevitability of technological progress in the economics of wind & solar with the inevitability of high wind & solar penetrations.
For example, without the correct alignment of incentives through rate structures even cheap batteries won’t have an impact. We cannot only rely on the cost of technology reducing. The path this energy transition takes depends on more than cheap solar panels and wind turbines.
What this means for the clean energy transition - there is no guarantee things will move in the correct way.
The Fourth Inconvenient Truth - Energy transitions enable new utility
The first three truths are ways in which this clean transition will be like the past. This final truth is a reality of the clean energy transition that moves against the past.
Why do we transition to new energy sources? New sources of energy allow us to do things we couldn’t do before. Coal enabled a revolution in manufacturing. Oil & gas enabled revolutions in transportation.
Historical energy transitions have enabled new utility by using higher quality fuels. One measurement of energy quality is energy density - how much energy we can squeeze into a given mass or volume.
Past transitions have been movements towards more energy dense fuels. Dry wood contains around 18 MJ/kg, anthracite coal 8-30 MJ/kg, oil 41-42 MJ/kg and methane (the primary component of natural gas) has 55 MJ/kg.
It’s difficult to compare renewables with fossil fuels on an energy density basis as renewables don’t consume fuel. Yet it is evident that water, sunlight and wind are powered by less dense forms of energy than burning oil or gas.
Even if we ignore that clean technologies reverse the energy density trend, the electricity generated by clean technologies is no different from what is supplied on the grid today. The clean energy transition lacks a killer app.
We are getting cleaner electricity but no major new form of utility. We are without a key driving force that helped to power previous transitions - the driving force of people wanting to heat their homes, power factories and fly around the globe.
One hope is the role that inverter based renewables & storage can play supporting the grid in services such as fast frequency response. Projects like Tesla’s South Australian battery are outperforming synchronous generators in providing these services. Is this enough to be compared with the coal fired revolutions in manufacturing or the oil & gas fired revolutions in mobility?
What this means for the clean energy transition - a key driving force that powered previous transitions won’t be helping this time.
Thanks for reading.