Humanity finds itself in a precarious situation in 2021. As the world population continues to grow past 7.5 billion and an ever-increasing number of people lift themselves out of poverty, the planet’s demand for energy shows little sign of slowing down. Greater energy consumption in isolation is not the problem; rising energy consumption has been closely linked with improving quality of life (Pasten 2012). The problem is that this increased energy demand continues to be covered largely by CO2 emitting sources of energy. Since the Kyoto Protocol of 1997 – a landmark climate agreement between 192 countries to reign in their greenhouse gas emissions – global emissions have risen by 50%, and as of 2019 fossil fuels still accounted for 84% total of energy consumption (UNFCCC 2021; Rapier 2020). Even the vast limitations imposed on tourism, industry, and other sectors of the economy as a result of the COVID-19 pandemic caused global energy consumption to decline by less than 5% in 2020 according to an annual BP Statistical Review (2021). This insatiable demand for energy, coupled with ever-increasing CO2 emissions is not sustainable for the planet – the question is what to do about it. 

Paradoxically, reaching net-zero emissions will likely cause global energy demand to soar even more rapidly. This is primarily due to electrification; “electrification refers to the process of replacing technologies that currently use fossil fuels (coal, oil, and natural gas) with technologies that use electricity as a source of energy” (Cleary 2019). This process is critical to decarbonizing many industries which are still heavily reliant on fossil fuels. Electrification has been identified by the International Energy Agency (IEA) as one of the most important drivers of emission reductions, responsible for around 20% of total reductions by 2050 on the path to net-zero emissions (Bouckaert and Pales et al. 2021). For example, the automotive industry, an industry long dominated by fossil fuels, is increasingly going electric (International Energy Agency 2020). Therefore, providing enough carbon-neutral electricity to cover all the activities that already use electricity as their primary source of energy today won’t be enough – the supply of clean electricity additionally needs to cover the added energy demand of all the additional industrial sectors that do not currently use electricity as their primary source of energy, such as transportation. In light of this, the IEA projects global demand for electricity to more than double between 2020 and 2050, with industry accounting for the largest absolute increase in electricity consumption: more than 11,000 TWh in the next 30 years (Bouckaert and Pales et al. 2021).

Even as renewable energies like wind and solar gain traction, they are associated with inherent challenges, and merely building enough capacity to cover the current demand will not be sufficient. Crucially, these types of energy generation are weather dependent, with seasonal as well as day-to-day fluctuations. These fluctuations in turn lead to imbalances between energy supply and demand; a critical factor for ensuring grid reliability (Wald 2021). A measure known as the capacity factor captures this phenomenon. The capacity factor is a ratio of the “actual amount of electricity generated by a plant compared to the maximum amount that it could potentially generate” if a power plant were running at full capacity all the time (Nuclear Energy Institute 2021). Nuclear Energy has the highest capacity factor of all sources of energy at almost 93%, more than twice as high as coal and two to three times higher than wind and solar energy at a capacity factor of 35% and 25% respectively; while renewables are bound by low capacity factors, the result of nighttime, clouds, and wind still days, nuclear plants can run regardless of weather conditions or time of day, and require comparatively little maintenance due to infrequent refueling (US Department of Energy 2021). The capacity factor is important because it means that to replace a nuclear power plant capable of generating 1 GW of output, it is not sufficient to install 1 GW of renewables or coal power. Based on their respective capacity factors it would require two to three coal plants and three to four renewable plants to reliably generate equivalent amounts of electricity (US Department of Energy 2021). Contrary to fossil fuels, whose combustion releases harmful carbon dioxide into the atmosphere, leading to dangerous warming of the earth’s surface, nuclear energy generates power through fission; the splitting of uranium atoms to produce energy in the form of heat. This heat is then used to create steam which in turn spins a turbine thereby generating electricity without producing CO2 (US Department of Energy 2021). As such, nuclear energy is one of the few clean-air sources capable of supplying energy regardless of time or weather, and without the emission of harmful greenhouse gases. 

One way to overcome the problem of discrepancies between energy supply and demand is to decouple these quantities by using large batteries to smooth out both short-term and seasonal imbalances between the two. Lithium-ion batteries seem like a promising choice, however, this type of battery is still far too expensive and doesn’t hold its charge for nearly long enough to be a viable option in this scenario (Temple 2018). Hydrogen produced through electrolysis with renewable electricity is a promising alternative in this regard, especially for overcoming the challenge of long-term seasonal storage; it can partially make use of existing infrastructure and can be stored as well as transported comparatively easily (Bouckaert and Pales et al. 2021). Unfortunately, this process is quite inefficient; Fusina, an Italian test plant designed to trial the implementation of this technology, was found to have an overall efficiency of just over 40% (Brunetti and Rossi et al. 2010). In other words, more than twice the amount of energy that will be needed to cover hypothetical seasonal demand will be required just to account for the inefficiencies related to storing this energy. In line with these findings, the IEA projects a substantial increase in the use of electricity for hydrogen production alone. Some 12,000 TWh in 2050; larger than the entire present-day electricity demand of China and the United States combined (Bouckaert and Pales et al. 2021). The energy sector is in many ways the foundation of efforts to reduce greenhouse gas emissions, facing the twin challenges of “cutting emissions nearly to zero by mid-century, while expanding to electrify and consequently decarbonize a much greater share of global energy use” (Jenkins and Luke et al. 2018: 2498).

Nuclear energy is not an alternative to renewable sources of energy, however. Rather, it complements the increased deployment of renewables by serving as a flexible backup source of energy generation which is capable of staying online consistently; this is important to balance out variations in demand and ensure sufficient backup capacity should a different power plant go offline, thereby increasing grid reliability (Pepin 2018). This is known as frequency regulation, a role currently fulfilled primarily by coal, oil, and natural gas; in the future, nuclear power shows promising potential to take over the important role of providing this standby capacity (Pepin 2018). Nuclear energy can also avoid the need to waste excess energy from renewables, the result of plant shutdowns when energy supply peaks above demand (Pepin 2018). Instead of disabling a wind turbine on a windy day with a high supply of renewable energy, a nuclear power plant providing a baseload energy generation would simply reduce its output allowing a greater share of renewable energy to enter the grid (Pepin 2018).

With an ever-increasing share of people moving into dense cities and almost 70% of the world’s population expected to live in urban areas by 2050, efficient land use will become increasingly important (United Nations 2018). Nuclear power produces more electricity on less land than any other clean-air source of electricity. As a comparison, wind farms require 360 times more land area to produce the same amount of electricity and solar requires 75 times the land area. Put a different way, it would require 1,145 wind turbines or 11.6 million solar panels to produce the same amount of power as a single commercial reactor, accounting for respective capacity factors (US Department of Energy 2021). In line with these findings, both the Intergovernmental Panel on Climate Change (IPCC), as well as the International Energy Agency (IEA), stress the importance of low-carbon energy sources like nuclear in preventing the worst of climate change, with the IEA proposing at least a doubling of the energy supply from nuclear power to keep global temperature increases within reasonable limits and reach net zero emissions by 2050 (Bouckaert and Pales et al. 2021; Rogelj and Shindell et al. 2018). 

Despite the increasing global demand for energy and our continued dependence on carbon-based forms of power generation, nuclear energy accounts for just 4% of the global energy mix, and its share fell by 0.7% between 2010 and 2018 (Rapier 2020; Olivier and Peters 2019). Without further lifetime extensions of existing nuclear power plants and new projects beyond those already under construction, nuclear power output will decline by another two-thirds over the next two decades (Bouckaert and Pales et al. 2021). From urbanization and increasing energy demand to land-use and lack of predictable generation; these factors make a transition to net-zero carbon emissions and a shift to renewables an immense challenge as it is. Simultaneously reducing the global share of nuclear power will inevitably delay this transition, while making it more complex and more expensive.

Given the continued rise in global emissions, it is clear that humanity needs to reduce CO2 emissions drastically in all sectors of the economy, to meet the goals of the 2015 Paris Climate Agreement and limit global warming to well below 2C. The strategy of replacing one CO2-neutral source of energy generation with another is not only an inefficient approach towards this end but will prolong the negative effects of climate change and increase the required capital investment necessary for this transformation (Hong and Bradshaw et al. 2015).


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