Electricity: the most important issue in the ecological transition
Electricity was undoubtedly the leading technology of the 20th century. No other technology has had such an impact on civilization. Nevertheless, it is one of (if not the) main source of greenhouse gas emissions, especially CO2. Today, it is mainly produced from fossil fuels, mainly coal, then gas. Hydroelectric dams, nuclear power and renewable energies account for just 17, 11 and 6% of the total respectively. Decarbonizing electricity is one of the most important and undoubtedly the most urgent projects. Indeed, the decarbonization of other aspects of energy (vehicle combustion engines and residential or industrial heat) and industry (e.g. fertilizers) will radically increase electricity consumption. Low-cost, low-carbon electricity is the prerequisite for just about everything else.
To grasp this subject, we need to understand several issues:
- electricity generation , of course, which needs to be decarbonized rapidly
- electricity storage , which is now crucial to the development of intermittent energies (ENR)
- electricity transmission , which poses problems not only because of intermittent energies (the grid needs to be adapted), but also in terms of locating production capacity
- electricity consumption : how much, when and why?
Note that we won’t be talking about the other energy consumed, heat, which will have its own dedicated site. Here, we’ll just be talking about electricity.
Nuclear, fossil, renewable electricity generation..
If today’s low-carbon energies are
Fossil electricity sources are :
- coal, which dominates
- gas
- oil, more marginal
Low-carbon electricity sources are essentially the following:
- Nuclear power, to which we have devoted a special report.
- Renewable energies, including :
- Large-scale hydropower (dams) and small-scale hydropower (run-of-river plants)
- Solar power
- Wind power
- Biomass, such as wood and biofuels.
Electricity storage and adaptation: the impossible stability
Today, electricity is stored mainly in the form of dams. They enable us to adapt to production peaks. A more elaborate version, the STEP, also pumps water. Other electricity storage methods are also being developed:
- Batteries , of course, which store energy in chemical form.
- Flywheels, already used on a very small scale due to their high reactivity.
- Power to Gas
- Compressed Air Energy Storage, CEAS
There are also processes designed to vary consumption to adapt to supply: modulation. We’ll look at this in more detail in our article on electricity supply stability.
Electricity transmission: unavoidable losses
Electricity transmission is extremely fast and efficient, but it’s not magic. It requires a complex infrastructure that breaks down into several blocks: extra-high, high, medium and low-voltage lines, transformers (to switch from one voltage to another), circuit breakers (to stop power in an emergency), etc
Intermittency is a particular challenge for electricity distribution circuits: they need to be able to cope with the extra load.
We also need to take a closer look at how the European electricity market works. How do exchanges between countries work? What regulations govern them?
It’s a highly technical subject that I can’t see myself dealing with in the short term. If you have any references on the subject to recommend to me, or if you’re an engineer who could explain its complexities to me, please e-mail me at alexandre.baumann {at} discoverthegreentech.com .