By Julio Ventero
In the Spanish energy debate there is a paradox that is difficult to explain: one of the sources that most contributes to lowering the price of electricity, reducing emissions and guaranteeing security of supply is, at the same time, one of the most questioned. Nuclear energy does not fail for technical or economic reasons. It fails, above all, due to ideological prejudices.
Let’s start with the essentials. Nuclear produces cheap electricity. It is not an opinion, it is an empirical result. Keeping depreciated plants in operation adds a large amount of firm energy to the system, with very low marginal costs. When that capacity remains available, the electricity market price tends to fall. And when it disappears, the gap is filled with more expensive technologies, which inevitably increases the bill.
In Spain, extending the useful life of existing nuclear plants would have a direct and significant impact on the wholesale price. These are reductions of up to double digits in the average annual price, a clear relief for both domestic consumers and the industry.
In a context of accelerated electrification and loss of industrial competitiveness in Europe, it is not a minor issue: it is a strategic variable.
Added to this effect on prices is another equally relevant effect: emissions. Nuclear is a technology free of CO₂ in generation. Replacing it with gas — as happens when reactors are shut down prematurely — automatically increases emissions from the electrical system. Maintaining it, on the other hand, allows for substantial reductions, even in scenarios with strong renewable deployment.
Here appears one of the arguments most repeated by detractors: that extending the life of nuclear plants slows down investment in renewables. The problem is that this reasoning does not hold up when real market incentives are analyzed.
If a renewable investment is profitable, it will be done. And if it is not done, it is not because nuclear exists, but because its costs or risks do not add up. Thinking that investors voluntarily give up profitable projects because there is too much cheap supply is tantamount to denying the basic functioning of a market economy.
In fact, the Spanish electricity market has proven to be competitive: prices reflect the marginal costs of generation. In that context, adding more low-cost supply can never raise the price structurally. At best, it can moderate the profitability of more expensive technologies. But that is not a failure of the system, it is precisely its logic.
There is also a factor that is little talked about and that is key: security of supply. Nuclear power plants provide inertia to the electrical system, an essential technical element to maintain the stability of the network.
Without it, the operator is forced to resort to combined cycles to provide adjustment services, even if renewables are available. More gas, more costs and more emissions. Nuclear power, silently, avoids all that.