Need some energy? Renewable or Nuclear today?
First of all, i would like to hightlight that renewable energies (RE) do not produce on demand or continuously, but at times that we do not control: we say that they are not controllable. For example, a wind turbine produces when the climatic conditions are right: when there is enough wind. We cannot “control” them and ask them to produce when we need electricity.
On the other hand, the times when RE produces the most are rarely the times when we need electricity the most. Solar energy, for example, produces mostly in the middle of the day when the sun is high. However, the peak of electricity consumption is usually in the evening, when the sun starts to set, and therefore when the production of solar energy is low.
To cope with this intermittency of renewable energies, there are some solutions. For example, electricity storage, which are very insufficient though to allow the efficient management of an electrical network.
This is why it is useful to have controllable power generation solutions that provide stable and scalable base load power generation to cope with fluctuations in renewable generation.
Controllable electricity production
However, there are not hundreds of controllable electricity production solutions. Today it can be coal, nuclear and gas, and some hydroelectric dams. Coal and gas are fossil fuels, which emit massive amounts of CO2. Nuclear power, on the other hand, is a low-carbon pilot solution: it even emits less CO2 than solar panels.
What is cheaper: nuclear or gas?
In reality, the opposition is once again artificial, because the same thing is not calculated in one case as in the other. In the case of nuclear power, we calculate the cost of a controllable energy, which can meet large-scale electricity needs, depending on the needs. In the case of renewable energy, on the contrary, we calculate the cost of an energy that cannot work by itself, cannot adapt its production to the needs.
The low cost of renewable energies is that of an energy well integrated into a pre-existing energy mix. And that cost is only low because there is a stable energy infrastructure that allows it to operate without the need for multiple electricity storage or grid management infrastructures. Basically, uncontrollable renewables are only cheap because there are still controllable energies (nuclear, coal, gas) that allow it to exist without the need to massively develop storage techniques or vastly oversize production capacities, as MIT researchers explained back in 2011 .
Without controllable energy, renewable energy would be significantly more expensive, as it is unable to produce simply according to need. Conversely, the cost of nuclear power increases because it must adapt to the random production of renewable energy. When renewable electricity production is high, nuclear power adapts its production downwards to ensure grid stability. In this case, the plants do not operate at full power, which increases the cost of nuclear production per kWh: in short, we continue to pay employees and engineers to operate a plant below its capacity.
In short, comparing one mode of production to another through their price does not make much sense because the price of one depends on the existence of the other. What would be more interesting to know is the average price of electricity according to the different modes of production that make up the energy mix, in a logic of global planning of the electrical system. And on this subject there is no consensus model.
Critics of nuclear energy
The European Commission unveiled, on the night of Friday 31 December to Saturday 1 January, a green label project for nuclear and gas power plants that aims to facilitate the financing of facilities that contribute to the fight against climate change. The Commission’s plan is “a mistake”, said German Environment Minister Steffi Lemke to the Funke media group. Nuclear technology, “which can lead to devastating environmental disasters — in case of serious accidents — and (…) leaves behind large amounts of highly radioactive and dangerous waste, cannot be sustainable,” she said.
Austrian Environment Minister Leonore Gewessler also criticized the project, denouncing nuclear power as “an energy of the past” that is “too expensive and too slow” to fight climate change.
What can be a solution?
Combining renewable energies with nuclear and gas-based generation for peak demand is a viable solution for a low-carbon energy mix. And this combination is not incompatible with the closure of certain aging nuclear power plants, quite the contrary. It is simply a matter of not rushing into it.
Considering dangerous nature of nuclear plants, Recently Bruxelles proposed to set conditions for the inclusion of nuclear and gas with a time limit: for the construction of new nuclear power plants, projects must have obtained a building permit before 2045; work to extend the life of existing plants must have been authorized before 2040. Guarantees regarding waste treatment and the dismantling of nuclear facilities at the end of their life are also required.
As for gas, described as a “transitional energy source”, investments will be recognized as “sustainable” for plants with low CO2 emissions. The Commission has set drastic thresholds: less than 100 grams of CO2 per kilowatt-hour, a threshold that experts say is unattainable with current technologies.
However, a transition period is foreseen: power plants obtaining their construction permit before December 31, 2030 will see this threshold raised to 270 grams of CO2 per kilowatt-hour, provided that they replace existing infrastructures that are much more polluting and meet a series of criteria.
 Managing Large-Scale Penetration of Intermittent Renewables. An MIT Energy Initiative Symposium April 20, 2011