A lot of conversations around sustainability happen around “energy” while the elephant in the room are “emissions”. Are these two related?
First of all, let’s look at how the various sectors of the economy consume energy, comparing it to how much GHG emissions they cause (sources for data are the Lawrence Livermore National Laboratory for energy use, and the EPA for GHG emissions). As you can see, measuring energy use gives a decent approximation also for the apportionment of emissions.
First big chunk: electricity
This makes the focus on electricity generation and transportation totally justified, as these two homogeneous sectors address over 50% of GHG emissions.
Decarbonizing electricity generation is – as we know – a complex endeavour where a sufficient RE generation capability is but a brick in a very big wall made of storage, grid balancing, grid stability and many other things which lie well beyond the comprehension limit of mere mortals: despite my degree in Nuclear Engineering I won’t claim I have more than a vague understanding of the challenges that need to be addressed.
However, I am suspicious of those chanting “It can’t be done, it won’t be done”; as I recently discussed in another post, this reminds me of the bumblebee paradox: traditional technical knowledge may be adamant it can’t be done, but obviously they didn’t bother telling Denmark, South Australia or Portugal and they went ahead and did it!
True, it was for a short period of time, but it was done nonetheless.
Among the scientists challenging the bumblebee’s inability to fly there is Mark Z. Jacobson of Stanford University who has repeatedly offered his perspective for 100% RE grids; recently, he shared a roadmap for the achievement of a 100% RE all energy use (not just electrical energy) for the State of Rhode Island, in response to that State passing legislation to achieve this target by 2033.
Second big chunk: transportation
As the Sankey diagram for energy (found at the LLNL link above) shows, Transportation is the worse economic sector when it comes to intelligent use of energy. While – as you can see in the total allocation on the right – about 2/3 of the energy we consume gets wasted, for Transportation that ratio goes up to 4/5 (box at the bottom).
If you want to see the importance of electrification in the global context of energy use rationalisation consider that an electric car requires only 1/4 of the energy of an internal-combustion one to drive the same distance:
If we were able to improve those two big chunks, we’d have gone a long way towards achieving our emission reduction objectives.
Why the electrification of transport is so important?
Transport of course means a lot of things, each with its own set of difficulties which of course will translate to opportunities for someone; in terms of priorities, however, the picture (data sourced from IEA) is once again very clear.
Since electric cars use much less energy, the electrification of passenger cars alone would save the world 1.7Gtons of emissions; moreover if meanwhile we reduced the EE carbon tenor from around 750 to 150g/kWh (still very far from a 100%RE grid) we would eliminate another 1.8 Gton, i.e. 3 out 8 “wedges” of our target reduction to 2050 (8 Gtons).
What prevents us from doing all this?
- While the overall energy supply (joules) is NOT a problem (if all the cars in the world today became electric, they would need only 25% of the global EE consumption; since it might take anywhere between 30 and 50 years to convert the whole stock, this is less than 1% of additional consumption) the local availability of sufficient power (watts) might be, so we need to make our grids more robust and more interconnected.
- Distributing all this energy requires a distribution infrastructure that does not exist; while there are players willing to build it, the capital outlay is significant and is at risk of a classic “chicken-and-egg” problem: i.e. the payback time for a charging station @ 1% occupancy is well beyond 10 years, making for an unattractive investment case.
- The dream of a 100% RE grid is fascinating, but it would be good enough to get to 80% to achieve our targets: RE overbuilding, storage and strong regional grids interconnections are the ingredients to achieve this; additionally, while Nuclear Power has managed to cancel itself from the candidates list thanks to stubborn, dramatic cost and time overruns and – short of good ideas – is peddling us the braindead concept of Small Modular Reactors as if a factory able to crank our SMRs as if they were phones or cars was readily available (hint: it’s not), existing NPPs should be kept in operations for as long as safety allows, because they DO offer low cost and low carbon electricity (more the latter than the former, since LCOE for nukes is nowadays not too distant than that of RE).