By Irina Slav
Many proponents of a zero-emission grid are firm opponents to nuclear power. It is not emission-free, they argue. It is dangerous because it uses radioactive materials. Now, one team of researchers has taken it one step further, suggesting that nuclear has no place at all in a zero-emission future. In a study published in Nature, the team, from the University of Sussex, the team argues that renewables and nuclear are mutually exclusive, and nuclear needs to be shunned in favor of solar and wind to advance the world’s emissions-cutting agenda.
The study used data from the World Bank and the International Energy Agency to suggest that renewables and nuclear “tend to exhibit lock-ins and path dependencies that crowd each other out,” according to a press release from the University of Sussex.
Basically, one of the messages of the authors is that nuclear is bad because it crowds out renewables and makes them less competitive. Grid structures optimized for nuclear and fossil fuel generation make distributed power costlier, they noted. Regulatory frameworks, finance markets, and employment practices were also in favor of conventional sources of power generation at the expense of renewables.
But the authors of the study also made another claim: that nuclear does not contribute all too much to the decline in carbon dioxide emissions.
“The study found that in countries with a high GDP per capita, nuclear electricity production does associate with a small drop in CO2 emissions,” the press release said. “But in comparative terms, this drop is smaller than that associated with investments in renewable energy. And in countries with a low GDP per capita, nuclear electricity production clearly associates with CO2 emissions that tend to be higher.”
Not surprisingly, the study attracted criticism. Some summarily dismissed it as pseudoscientific, while others took the time to address the main arguments. Alex Gilbert, an energy analyst, took to Twitter to explain the problems with the study in detail. While the authors acknowledged their study had found correlation rather than causation between nuclear and renewables, and emissions, they based their conclusions on the assumption of causality, he said, among other things.
Interpreting the correlation between events or trends as causality is a dangerous trap for researchers. And the claim that nuclear leads to higher emissions is indeed problematic if we look at contemporary data. Germany, a leader in renewable energy, has much higher emissions than neighboring France, which relies a lot on nuclear power: 289 g of CO2 equivalent per kWh of electricity for Germany versus just 44 g for France. France has no solar capacity and only a little wind capacity, but it has close to 40 GW of nuclear capacity. Even parts of Denmark, the poster child of renewables and a country much smaller than both France and Germany, have a higher emissions load than France.
But let’s leave emissions aside for a moment, blasphemous as this may seem to those who prioritize them above all else. Even if one dismisses critics of the study as nuclear shills, there are certain immutable facts that are relevant in a discussion of renewables versus nuclear. Nuclear plants produce dispatchable power. This means that when the grid needs it, they can supply it. The same is true for fossil fuel generation. It is not, however, true for solar and wind. The advantage of nuclear over both solar and wind is that in addition to emitting no carbon dioxide during the generation process, it can supply all the power that the grid needs on-demand.
Perhaps storage could change this in the future: storage can boost renewables’ competitiveness in terms of reliability of supply immensely. Yet storage so large and affordable as to make economic sense is yet to be developed. And while there are always vested interests on both sides, even the International Energy Agency has warned that a zero-emission future is impossible without nuclear power.
“Without policy changes, advanced economies could lose 25% of their nuclear capacity by 2025 and as much as two-thirds of it by 2040,” the agency warned last year. As a result of this, the IEA went on to say, the planet could suffer as much as 4 billion tons of carbon dioxide in additional emissions.
We don’t even need a lot of new nuclear plants to avoid that, according to the IEA. We could simply extend, instead of shortening, the lives of nuclear plants already in operation. That’s also economical because new nuclear facilities take many years to plan, build, and commission. In this respect, solar and wind are definitely the better choice: they can be deployed in less than half the time. But pitting them against nuclear in an either/or scenario may well be going a tad too far. Most experts seem to agree that solar, wind, and nuclear can co-exist perfectly peacefully in a zero-emission world, without “crowding each other out.”