The International Energy Agency (IEA) in a new report, “Net Zero by 2050: A Roadmap for the Global Energy Sector” released on 18 May assesses the policy requirements, the deployment and innovation needs and the necessary investments needed to achieve that goal. It also looks at the economic benefits and wider global implications.
The 224-page report has three main aims:
- To examine the impacts of announced net-zero emissions pledges and what they might mean for the energy sector;
- To develop a new energy-sector pathway towards achieving net-zero emissions globally by 2050; and
- To set out key policy recommendations for governments to act upon in the near-term, and a long-term agenda for change to achieve net-zero goals as well as other Sustainable Development Goals.
IEA said the report is the world’s first comprehensive study of how to transition to a net zero energy system by 2050 while ensuring stable and affordable energy supplies, providing universal energy access, and enabling robust economic growth. “It sets out a cost-effective and economically productive pathway, resulting in a clean, dynamic and resilient energy economy dominated by renewables like solar and wind instead of fossil fuels. The report also examines key uncertainties, such as the roles of bioenergy, carbon capture and behavioural changes in reaching net zero.”
In his Foreword to the report IEA Executive Director Dr Fatih Birol says: “We are approaching a decisive moment for international efforts to tackle the climate crisis – a great challenge of our times. The number of countries that have pledged to reach net-zero emissions by mid-century or soon after continues to grow, but so do global greenhouse gas emissions. This gap between rhetoric and action needs to close if we are to have a fighting chance of reaching net zero by 2050 and limiting the rise in global temperatures to 1.5°C.
Doing so requires nothing short of a total transformation of the energy systems that underpin our economies.
He notes that 2021 is a critical year at the start of a critical decade for these efforts with the 26th Conference of the Parties (COP26) of the United Nations Framework Convention on Climate Change scheduled for November. He adds: “The pathway laid out in our Roadmap is global in scope, but each country will need to design its own strategy, taking into account its specific circumstances. There is no one-size-fits-all approach to clean energy transitions.”
In the 15-page summary for policymakers, nuclear is only mentioned twice. Noting that ever-cheaper renewable energy technologies give electricity the edge in the race to zero, IEA says: “Hydropower and nuclear, the two largest sources of low-carbon electricity today, provide an essential foundation for transitions.”. By 2050, almost 90% of electricity generation comes from renewable sources, with wind and solar PV together accounting for nearly 70%, it says, adding: “Most of the remainder comes from nuclear.”
Chapter 1 of the main report looks at CO2 emissions and energy supply and use based on existing policies and pledges. This includes two scenarios: the Stated Policies Scenario (STEPS), which takes account only of specific policies that are in place or have been announced by governments and the Announced Pledges Case (APC), which assumes that all announced national net zero pledges are achieved in full and on time, whether or not they are currently underpinned by specific policies.
Chapter 2 presents the Net-Zero Emissions by 2050 Scenario (NZE), which describes how energy demand, and the energy mix will need to evolve if the world is to achieve that goal. Chapter 3 examines the implications of the NZE for various sectors. It highlights the key changes required and the major milestones that are needed along the way. Chapter 4 explores the implications of the NZE for the economy, the energy industry, citizens and governments.
With respect to nuclear, IEA says that under STEPS, nuclear energy grows by 15% between 2020 and 2030, mainly reflecting expansions in China. Under APC, “nuclear maintains its share of the energy mix, with output rising by a quarter to 2030, driven by lifetime extensions at existing plants and new reactors in some countries”. By 2050, under APC, solar PV and wind together account for almost half of electricity supply. Hydropower also expands, emerging as the third-largest energy source in the electricity mix while “nuclear power increases steadily too, maintaining its global market share of about 10%, led by increases in China”.
The energy mix in 2050 in the NZE is much more diverse than today, IEA says. In 2020, oil provided 30% of total energy supply, coal 26% and natural gas 23%. In 2050, renewables provide two-thirds of energy use, including bioenergy, wind, solar, hydroelectricity and geothermal. “There is also a large increase in energy supply from nuclear power, which nearly doubles between 2020 and 2050.” As to hydrogen production, an increasing share of hydrogen production comes from electrolysers, which account for 60% of total production in 2050. “Electrolysers are powered by grid electricity, dedicated renewables in regions with excellent renewable resources and other low-carbon sources such as nuclear power.”
Taking a more detailed look at hydrogen production in Chapter 3, IEA says that by 2050, hydrogen production in the NZE is almost entirely based on low-carbon technologies: water electrolysis accounts for more than 60% of global production, and natural gas in combination with carbon capture, use and storage (CCUS) for almost 40%. “Electrolysis absorbs close to 15 000 terawatt-hours (TWh), or 20% of global electricity supply in 2050, largely from renewable resources (95%), but also from nuclear power (3%) and fossil fuels with CCUS (2%).
With respect to the electricity sector, IEA says nuclear power makes a significant contribution in the NZE, “its output rising steadily by 40% to 2030 and doubling by 2050, though its overall share of generation is below 10% in 2050”. At its peak in the early 2030s, global nuclear capacity additions reach 30 GW a year, five-times the rate of the previous decade. In advanced economies, lifetime extensions for existing reactors are pursued in many countries, while new construction expands to about 4.5 GW a year on average from 2021 to 2035, with increasing emphasis on small modular reactors (SMRs). “Despite these efforts, the nuclear share of total generation in advanced economies falls from 18% in 2020 to 10% in 2050. Two-thirds of new nuclear power capacity in the NZE is built in emerging market and developing economies mainly in the form of large-scale reactors, where the fleet of reactors quadruples to 2050. This raises the share of nuclear in electricity generation in those countries from 5% in 2020 to 7% in 2050.” Nuclear also meets 4% of commercial heat demand in 2050.
IEA notes that nuclear power technologies have advanced in recent years, with several first-of-a-kind large-scale reactors with enhanced safety completed on schedule in China, Russia and the United Arab Emirates. However, there have been substantial delays and cost overruns in Europe and the USA. SMRs and other advanced reactor designs “are moving towards full-scale demonstration, with scalable designs, lower upfront costs and the potential to improve the flexibility of nuclear power in terms of both operations and outputs, eg electricity, heat or hydrogen”.
IEA lists three important sets of decisions that need to be made concerning nuclear power: lifetime extensions; pace of new construction; and advances in nuclear power technology. In advanced economies, these decisions concern new construction and the large number of NPPS that may be retired over the next decade.
“Without further lifetime extensions and new projects beyond those already under construction, nuclear power output in advanced economies will decline by two-thirds over the next two decades.”
In emerging market and developing economies, decisions concern the pace of new nuclear power construction. From 2011 to 2020, an average of 6 GW of new nuclear capacity came online each year. By 2030, this increases to 24 GW a year in the NZE. Further decisions concerns the extent of government support for advanced nuclear technologies, particularly related to SMRs and high-temperature gas reactors, which can expand markets for nuclear power beyond electricity.
“Failing to take timely decisions on nuclear power and CCUS would raise the costs of a netzero emissions pathway and add to the risk of not meeting the goal by placing an additional burden on wind and solar to scale up even more quickly than in the NZE.”
Criticism from WNA
In a lengthy press release the same day, the World Nuclear Association (WNA) says the IEA’s Net Zero Emissions scenario “puts too much faith in technologies that are uncertain, untested, or unreliable and fails to reflect both the size and scope of the contribution nuclear technologies could make”. WNA notes that the NZE scenario’s projection for nuclear growth sees the share of nuclear energy in the global electricity mix falling from 10.5% to 8%. “Given that more than 60% of the world’s electricity is currently generated by fossil fuels, if we are to eliminate them in less than 30 years, the IEA’s assessment of the role of nuclear is highly impractical.”
WNA Director General Sama Bilbao y León, commented, “The IEA makes it clear that nuclear energy will be an essential component of a global net-zero emissions energy transition. Governments must now take action to ensure that nuclear energy can play a major role in the clean energy transition to which so many of them have now committed.”
WNA notes that, in addition to electricity, nuclear energy can generate zero-carbon heat. “This is an opportunity that the IEA’s report barely touches on. Existing reactors are already being used to provide steam for district heating systems and to produce fresh water. New reactor designs under development and deployment could provide heat and feedstocks for industry (chemicals, steel, concrete, cement), fuels for heavy transport (shipping, aviation) or generate hydrogen directly.”
WNA points out that IEA’s NZE scenario relies on other low carbon generation, particularly wind and solar, to a much higher degree than nuclear. “While the base cost of wind and solar has decreased substantially in recent years, the share of generation projected for these intermittent technologies would require back-up generation or energy storage, and overall grid management on a scale far greater than has been demonstrated, either in terms of cost, reliability or practicality.”
In addition, increasing wind, solar and batteries “could place an enormous strain on the supply of minerals that they need”. WNA notes that a recent IEA report highlights a mismatch between global climate ambitions and the availability of critical minerals that could mean a slower and more expensive energy transition. Moreover, IEA “identified that nuclear is one of the low-carbon technologies with the lowest mineral intensity and smallest land footprint”.
WNA criticises IEA for depending so heavily on expanding intermittent wind and solar, and “relying so heavily on as yet unproven at scale modern bioenergy, battery storage and hydrogen to cover for this intermittency”, adding that the NZE scenario “carries with it a high degree of unnecessary risk”.
Sama Bilbao y León concluded: “The IEA’s Net Zero Emissions report sets a target that we must achieve. However, their scenario puts too much faith in solutions that are uncertain, untested, or unreliable. Proven nuclear energy technologies have demonstrated their ability to take a much larger role in electricity decarbonization in many countries around the world and have the potential to lead decarbonization in many other energy sectors. We urge the IEA to explore in more detail the potential for nuclear energy to make a much greater contribution towards global decarbonization, and to help governments assess what steps they need to take to unlock the contribution of nuclear energy for a net-zero future.”
