World Energy Needs and Nuclear Power

  • The world will need significantly increased energy supply in the future, especially cleanly-generated electricity.
  • Electricity demand is increasing about twice as fast as overall energy use and is likely to rise by more than half to 2040.
  • Nuclear power provides about 10% of the world's electricity, and 18% of electricity in OECD countries.
  • Almost all reports on future energy supply from major organizations suggest an increasing role for nuclear power as an environmentally benign way of producing reliable electricity on a large scale.

Growth in the world's population and economy, coupled with rapid urbanisation, will result in a substantial increase in energy demand over the coming years. The United Nations (UN) estimates that the world's population will grow from 7.8 billion in 2020 to around 8.5 billion in 2030 and 9.7 billion by 2050. The process of urbanization – which currently adds a city the size of Shanghai to the world's urban population every four months or so – will result in approximately two-thirds of the world's people living in urban areas by 2050 (up from about 55% at present). The challenge of meeting rapidly growing energy demand, whilst reducing harmful emissions of greenhouse gases, is considerable. In 2019 global energy-related carbon dioxide (CO2) emissions rose to 33.3 Gt, the highest on record, and about 45% above the total in 2000 (23.2 Gt). In 2020, due to the response to the coronavirus pandemic, primary energy demand dropped by nearly 4%, and CO2 emissions fell by 5.8%. In 2021 CO2 emissions bounced back to pre-pandemic levels, rising by 5% to 33 Gt.

Electricity demand growth has outpaced growth in final energy demand for many years. Increased electrification of end-uses – such as transport, space cooling, large appliances, and ICT – are key contributors to rising electricity demand. The number of people without access to electricity has fallen substantially, and is now below one billion. However, despite significant progress, 733 million people – 9.4% of the world’s population – mostly in rural areas, live without access (data for 2020).

Aside from the challenges of meeting increasing demand and reducing greenhouse gas emissions, cleaner air is a vital need. According to the World Health Organization (WHO), air pollution is the world's largest environmental risk. The WHO estimates that about seven million people die prematurely as a result of air pollution. Much of the fine particulate matter in polluted areas arises from industrial sources such as power generation or from indoor air pollution which could be averted by electricity use.

Nuclear energy is a low-emitting source of electricity production and is also specifically low-carbon, emitting among the lowest amount of carbon dioxide equivalent per unit of energy produced when considering total life-cycle emissions. It is the second largest source of low-carbon electricity production globally (after hydropower), and provided about 30% of all low-carbon electricity generated in 2019. Almost all reports on future energy supply from major organizations suggest an expanded role for nuclear power is required, alongside growth in other forms of low-carbon power generation, to create a sustainable future energy system.

In June 2019 the OECD’s International Energy Agency (IEA) published a report, Nuclear Power in a Clean Energy System, which concluded that a failure to invest in existing and new nuclear plants in advanced economies would make global efforts to transition to a cleaner energy system drastically harder and more costly.

In June 2022 the IEA report on Nuclear Power and Secure Energy Transitions concluded that nuclear energy can “help make the energy sector's journey away from unabated fossil fuels faster and more secure,” with nuclear being “well placed to help decarbonise electricity supply”. The report emphasizes the significant role nuclear plants can play in securing the global pathway to net zero.

Primary energy and electricity outlook

There are many outlooks for primary energy and electricity published each year, many of which are summarized below. Among the most widely-referenced organizations in this regard is the IEA. Each year, the IEA releases its World Energy Outlook (WEO), setting out the current situation and presenting a number of forward-looking scenarios. The report's 'Current Policies Scenario' considers only policies firmly enacted at the time of writing, whilst the 'New Policies Scenario' – the central scenario, renamed 'Stated Policies Scenario' in WEO 2019 – incorporates policies firmly enacted as well as an assessment of the results likely to stem from announced policy intentions. In each recent WEO report, a third scenario is included that starts with a vision of how and over what timeframe the energy sector needs to change – primarily to decarbonize – and works back to the present. In each WEO released over 2008-2016, the main decarbonisation scenario had been the '450 Scenario'; a scenario consistent with limiting the rise in average global temperatures to 2°C. In WEO-2017, the 450 Scenario was replaced by a new, 'Sustainable Development Scenario'. This presents a pathway that would address three principal objectives for building a sustainable, modern energy system: access to affordable, clean and reliable energy; reduction of air pollution; and effective action to combat climate change. For more information on sustainability, see information page on Nuclear Energy and Sustainable Development.

In the WEO 2021 'Stated Policies Scenario' ('STEPS'), global energy needs rise by about 26% to 2050, and global electricity demand nearly doubles. Growth in demand comes largely from emerging markets and developing economies. Almost all net growth in demand is met by low emissions sources, but annual emissions remain at about current levels.

In the STEPS scenario, China’s energy demand reduces slightly between 2030 and 2050, but in 2050 still accounts for 45% of world total.

There are many changes ahead in the sources of primary energy used. The dominance of fossil fuels is reduced modestly across the scenarios, declining from 79% of total primary demand in 2020, to 66% by 2050 in the STEPS scenario and 33% in the Sustainable Development Scenario. Despite the relative decrease, the absolute amount of energy consumed either directly or indirectly through the burning of fossil fuels increases by over 5% to 2050 in the STEPS scenario, and decreases by about 55% in the Sustainable Development Scenario. The proportion of final energy consumption that is in the form of electricity increases from 19% in 2020, to 26% by 2050 in the STEPS scenario, and to 40% in the Sustainable Development Scenario.

As the use of electricity grows significantly, the primary energy sources used to generate it are changing. In 2020, 61% of the electricity generated globally was through the burning of fossil fuels. Whilst the STEPS scenario sees this figure reduced to 32% of the total, absolute electricity generation in 2050 from fossil fuels remains at 98% of 2020 levels. The Sustainable Development Scenario sees the fossil fuel share of generation markedly reduced to just 7% of total generation by 2050, with absolute generation 21% of that in 2020. In both scenarios, generation from all low-carbon sources of electricity is required to grow substantially. 

Nuclear power for electricity in published scenarios

Nuclear power generation is an established part of the world's electricity mix providing about 10% of world electricity. It is especially suitable for meeting large-scale, continuous electricity demand where reliability and predictability are vital – hence ideally matched to increasing urbanisation worldwide.

MIT Future of Nuclear Energy in a Carbon-Constrained World

A major two-year study by the Massachusetts Institute of Technology Energy Initiative (MITEI) published in September 2018 underlined the pressing need to increase nuclear power generation worldwide. It outlined measures to achieve this, including moves to reduce the cost of building new nuclear capacity and creating a level playing field that would allow all low-carbon generation technologies to compete on their merits. "While a variety of low- or zero-carbon technologies can be employed in various combinations, our analysis shows the potential contribution nuclear can make as a dispatchable low-carbon technology. Without that contribution, the cost of achieving deep decarbonisation targets increases significantly," the study finds. The MIT study is designed to serve as a balanced, fact-based, and analysis-driven guide for stakeholders involved in nuclear energy, notably governments.

With high carbon constraints, the system cost of electricity without nuclear power is twice as high in the USA and four times as high in China according to the MIT study.* Scenarios envisage nuclear comprising over half of capacity in the USA and over 60% in China if overall carbon emissions are reduced to 50 g/kWh.

* Nominal overnight capital cost of nuclear is $5500/kW in the USA and $2800/kW in China, possibly reducing to $4100 and $2100/kW.

IEA: World Energy Outlook

Annual editions of WEO from the OECD IEA make clear the increasing importance of electricity, with all scenarios expecting demand growth to outpace that of total final energy demand. Also clear across successive reports is the growing role that nuclear power will play in meeting global energy needs, while achieving security of supply and minimising carbon dioxide and air pollutant emissions.

WEO 2021, referred to above, presents electricity generation growth of between 75% and 116% over 2020-2050 across its three main scenarios. In the report's Sustainable Development Scenario, nuclear generation increases by 2022 TWh (75%) over the same period, requiring capacity growth of about 254 GW, or 61%.

WEO 2020 presents electricity generation growth of between 46% and 51% over 2018-2040 across its two main scenarios (the 2020 publication did not include a New Policies Scenario). In the Stated Policies Scenario, the report's central scenario, annual nuclear generation increases by 729 TWh (27%) between 2018 and 2040, requiring an increase in capacity of 59 GW, or 14%. In the report's Sustainable Development Scenario, nuclear generation increases by 1610 TWh (60%) over the same period, requiring capacity growth of about 179 GW, or 43%.

WEO 2019 presents electricity generation growth of between 51% and 67% over 2017-2040 across its three scenarios. In the Stated Policies Scenario, the report's central scenario, annual nuclear generation increases by 839 TWh (32%) between 2017 and 2040, requiring an increase in capacity of 69 GW, or 17%. In the report's Sustainable Development Scenario nuclear generation increases by 1773 TWh (67%) over the same period, requiring capacity growth of about 188 GW, or 46%. 

WEO 2018 presents electricity generation growth of between 49% and 72% over 2016-2040 across its three scenarios. In the New Policies Scenario, the report's central scenario, annual nuclear generation increases by 1121 TWh (43%) between 2016 and 2040, requiring an increase in capacity of about 100 GW, or 25%. In the report's Sustainable Development Scenario nuclear generation increases by 2355 TWh (90%) over the same period, requiring capacity growth of about 265 GW, or 65%. 

WEO 2017 presents electricity generation growth of between 48% and 75% over 2015-2040 across its three scenarios. In the New Policies Scenario, nuclear generation increases by 1273 TWh (50%) between 2015 and 2040, requiring an increase in capacity of about 100 GW, or 25%. In the report's Sustainable Development Scenario, nuclear generation increases by 2774 TWh (108%) over the same period, requiring capacity growth of about 300 GW, or 75%.

WEO 2016 presents electricity generation growth of between 43% and 78% over 2014-2040 across its three scenarios. In the New Policies Scenario, nuclear generation increases by 1997 TWh (78%) between 2014 and 2040, requiring an increase in capacity of about 200 GW, or 45%. In the report's 450 Scenario, nuclear generation increases by 3566 TWh (141%) over the same period, requiring capacity growth of about 300 GW, or 95%.

WEO 2015 presents electricity generation growth of between 45% and 84% over 2013-2040 across its three scenarios. In the New Policies Scenario, nuclear generation increases by 2128 TWh (86%) between 2013 and 2040, requiring an increase in capacity of about 220 GW, or 55%. In the report's 450 Scenario, nuclear generation increases 3765 TWh (152%) over the same period, requiring capacity growth of about 450 GW, or 115%.

In June 2015 the IEA’s World Energy Outlook 2015 Special Report on Energy and Climate Change was published, which “has the pragmatic purpose of arming COP21 negotiators with the energy sector material they need to achieve success in Paris in December 2015”. It outlines a strategy to limit global warming to 2°C, but is very much focused on renewables.

The report recommended a series of measures including increasing energy efficiency, reducing the use of inefficient coal-fired power plants, increasing investment in renewables, reducing methane emissions, and phasing out fossil fuels subsidies. Half of the additional emissions reductions in its 450 Scenario come from decarbonisation efforts in power supply, driven by high carbon price incentives. In this scenario, an additional 245 GWe of nuclear capacity is built by 2040 compared with a moderate ‘Bridge’ option. The IEA acknowledges that nuclear power is the second-biggest source of low-carbon electricity worldwide after hydropower and that the use of nuclear energy has avoided the release of 56 billion tonnes of CO2 since 1971, equivalent to almost two years of global emissions at current rates. The report suggests that intended nationally determined contributions (INDCs) submitted by countries in advance of COP21 will have trivial effect, and its purpose is clearly to suggest more ambitious emission reduction targets in its ‘Bridge’ scenario.

While the report confirms that nuclear energy needs to play an important role in reducing greenhouse gas emissions, it projects nuclear capacity of only 542 GWe (38% increase), producing 4005 TWh, by 2030 in its main ‘Bridge’ scenario. Most of the new nuclear plants are expected to be built in countries with price-regulated markets or where government-owned entities build, own, and operate the plants, or where governments act to facilitate private investment.

WEO-2014 had a special focus on nuclear power, and extended the scope of scenarios to 2040. In its New Policies Scenario, installed nuclear capacity growth is 60% through 543 GWe in 2030, and to 624 GWe in 2040 out of a total of 10,700 GWe, with the increase concentrated heavily in China (46% of it), plus India, Korea, and Russia (30% of it together) and the USA (16%), countered by a 10% drop in the EU. Despite this, the percentage share of nuclear power in the global power mix increases to only 12%, well below its historic peak. The 450 Scenario gives a cost-effective transition to limiting global warming assuming an effective international agreement in 2015, and this brings about a more than doubling of nuclear capacity to 862 GWe in 2040, while energy-related CO2 emissions peak before 2020 and then decline. In this scenario, almost all new generating capacity built after 2030 needs to be low-carbon.

"Despite the challenges it currently faces, nuclear power has specific characteristics that underpin the commitment of some countries to maintain it as a future option," it said. "Nuclear plants can contribute to the reliability of the power system where they increase the diversity of power generation technologies in the system. For countries that import energy, it can reduce their dependence on foreign supplies and limit their exposure to fuel price movements in international markets."

Carbon dioxide emissions from coal use level off after 2020 in the New Policies Scenario, though CCS is expected to be negligible before 2030. CO2 emissions from gas grow strongly to 2040.

WEO-2014 expressed concern about subsidies to fossil fuels, “which encourage wasteful consumption” and totalled $548 billion in 2013, over half of this for oil. Ten countries account for almost three-quarters of the world total for fossil-fuel subsidies, five of them in Middle East (notably Iran and Saudi Arabia) or North Africa where much electricity is generated from oil, and where nuclear power plants and renewables would be competitive, but for those subsidies. The report advocates ensuring “that energy prices reflect their full economic value by introducing market pricing and removing price controls.” Renewables subsides in 2013 are put at $121 billion and rising, $45 billion of this being solar PV. Geographically this is $69 billion for EU and $27 billion in USA. The report was unable to assign a figure for nuclear subsidies, which at present don’t exist. 

Following the Fukushima accident, WEO-2011 New Policies Scenario had a 60% increase in nuclear capacity to 2035, compared with about 90% the year before. "Although the prospects for nuclear power in the New Policies Scenario are weaker in some regions than in [WEO-2010] projections, nuclear power continues to play an important role, providing base-load electricity. ... Globally, nuclear power capacity is projected to rise in the New Policies Scenario from 393 GW in 2009 to 630 GW in 2035, around 20 GW lower than projected last year." In this scenario the IEA expected the share of coal in total electricity to drop from 41% now to 33% in 2035. WEO-2011 also included a "Low Nuclear Case (which) examines the implications for global energy balances of a much smaller role for nuclear power. Its effect would be to "increase import bills, heighten energy security concerns and make it harder and more expensive to combat climate change."

IEA: Net Zero by 2050

Net Zero by 2050, released in May 2021, outlines a possible roadmap for the global energy sector to achieve net zero emissions by mid-century. In the roadmap, the amount of energy provided by nuclear nearly doubles between 2020 and 2050. To achieve this, new capacity additions reach 30 GW per year in the early 2030s. 

The amount of energy consumption that is in the form of electricity increases from about 20% today to about 50% by 2050. Whilst absolute supply from nuclear increases, its relative contribution to the electricity mix decreases from about 10.5% in 2020 to about 8% in 2050. 

The report warned: “Failing to take timely decisions on nuclear power ... would raise the costs of a net-zero emissions pathway and add to the risk of not meeting the goal.” 

IEA: Energy Technology Perspectives

Energy Technology Perspectives (ETP) 2020 from the IEA says that, with a rising share of electricity in final consumption, “the technological transformation of the power generation sector is a central element of the clean energy transition. Decarbonisation drives down the carbon intensity of electricity generation: it falls from 463 grams of CO2 per kilowatt-hour in 2019 to below zero in net terms around 2055.” However, in its Sustainable Development scenario with a threefold increase in total power generation, it projects only 780 GWe nuclear providing 8% in 2070. To support its projection of 84% from renewables, it projects 2100 GWe of utility-scale storage including 300 GWe pumped hydro, the rest being mainly by batteries with an average discharge duration of five hours. 

ETP 2017 analyses various energy sector development paths to 2060 and notes: “In the power sector, renewables and nuclear capacity additions supply the majority of demand growth... Innovative transportation technologies are gaining momentum and are projected to increase electricity demand." Rising living standards will increase demand. “Nuclear power benefits from the stringent carbon constraint in the [Beyond 2 Degrees Scenario], with its generation share increasing to 15% by 2060 and installed capacity compared with today more than doubling to 1062 GWe by 2060. Of this, 64% is installed in non-OECD countries, with China alone accounting for 28% of global capacity... Achieving this long-term deployment level will require construction rates for new nuclear capacity of 23 GWe per year on average between 2017 and 2060." (p295)

ETP-2016 focused on the urban environment, since cities “represent almost two-thirds of global primary energy demand and account for 70% of carbon emissions in the energy sector.” Its 2DS scenario to 2050 gives a major role to renewables in reducing emissions and much less to nuclear power, while maintaining optimism on CCS. For electricity, generation is almost completely decarbonized by 2050, achieved with 67% renewables including hydro (30% solar PV and wind), 12% coal and gas with CCS, and 16% nuclear (about 7000 TWh, from 914 GWe). Electric vehicles will account for 450 TWh. However, it notes that CCS development is languishing and “is not on a trajectory to meet the 2DS target of 540 Mt CO2 being stored per year in 2025,” and in 2015 “only 7.5 Mt/yr (27%) of the captured CO2 is being stored with appropriate monitoring and verification.”

ETP-2015 developed the earlier scenarios. In the main 2DS scenario, the share of fossil fuels in global primary energy supply drops by almost half – from 80% in 2011 to just over 40% in 2050. Energy efficiency, renewables and CCS make the largest contributions to global emissions reductions under the scenario. Under the 2DS scenario, some 22 GWe of new nuclear generating capacity must be added annually by 2050.

Launching ETP 2015, the IEA said: "A concerted push for clean-energy innovation is the only way the world can meet its climate goals," and that governments should help boost or accelerate this transformation."

ETP-2014 developed the ETP 2012 scenarios. In the 2DS one which is the main focus, some 22 GWe of new nuclear generating capacity must be added annually by 2050. However, the IEA notes that global nuclear capacity "is stagnating at this time" and by 2025 will be 5% to 25% below needed levels, "demonstrating significant uncertainty." It suggests that the high capital and low running costs of nuclear create the need for policies that provide investor certainty.

The IEA estimated that an additional $44 trillion in investment was needed in global electricity systems by 2050. However, it says that this represents only a small portion of global GDP and is offset by over $115 trillion in fuel savings.

Launching the ETP 2014 report, the IEA executive director said: "Electricity is going to play a defining role in the first half of this century as the energy carrier that increasingly powers economic growth and development. While this offers opportunities, it does not solve our problems; indeed, it creates many new challenges."

International Atomic Energy Agency

In the 2022 edition of the International Atomic Energy Agency's (IAEA's) Energy, Electricity and Nuclear Power Estimates for the Period up to 2050, the high case projection has global nuclear energy capacity increasing from 390 GWe in 2021 to 479 GWe by 2030, 676 GWe by 2040 and 873 GWe by 2050. In the high case, 5.3% of generating capacity is provided by nuclear in 2050, up from 4.8% in 2021.

The IAEA's low case projection assumes a continuation of current market technology and resource trends with few changes to policies affecting nuclear power. It is designed to produce "conservative but plausible" estimates. It does not assume that all national targets for nuclear power will be achieved. Under this projection, nuclear capacity decreases to 381 GWe by 2030, before recovering slightly to 392 GWe by 2040 and 404 GWe by 2050.

These projections represent an increase from those presented in the 2020 edition of Energy, Electricity and Nuclear Power Estimates for the Period up to 2050, where nuclear generating capacity increases to 475 GWe by 2030, 622 GWe by 2040 and 715 GWe by 2050 in the high case. Low case projections have also increased from 369 GWe by 2030, 349 GWe by 2040, and 363 GWe by 2050.

Earlier projections from the IAEA had suggested a significantly stronger growth outlook for nuclear energy. For example, in the 2012 edition of Energy, Electricity and Nuclear Power Estimates for the Period to 2050, the IAEA's low projection showed a nuclear capacity increase from 370 GWe in 2011 to 456 GWe in 2030; the high case for that year was 740 GWe. For 2050 it projected 469 GWe and 1137 GWe respectively. The projected figures in the 2012 edition for the year 2020 ranged from 421 GWe (low case) to 528 GWe (high case); the actual figure for nuclear capacity in 2020 was 393 GWe.

OECD Nuclear Energy Agency

The 2015 edition of the joint NEA-IEA Nuclear Technology Roadmap asserts that “current trends in energy supply and use are unsustainable,” and “the fundamental advantages provided by nuclear energy in terms of reduction of GHG emissions, competitiveness of electricity production and security of supply still apply” (from 2010). It puts forward a 2050 carbon-limited energy mix scenario providing about 40,000 TWh in which 930 GWe of nuclear capacity supplies 17% of electricity but plays an important role beyond that. "The contributions of nuclear energy – providing valuable base-load electricity, supplying important ancillary services to the grid and contributing to the security of energy supply – must be fully acknowledged." Governments should "review arrangements in the electricity market so as to... allow nuclear power plants to operate effectively."

"Clearer policies are needed to encourage operators to invest in both long-term operation and new build so as to replace retiring units," said the report. "Governments should ensure price transparency and the stable policies required for investment in large capital-intensive and long-lived base-load power. Policies should support a level playing field for all sources of low-carbon power projects." This is particularly important to OECD countries, where nuclear power is the largest source of low-carbon electricity, providing 18% of their total electricity. Even though the use of electricity grows over the timeframe to 2050, the increase of nuclear power from 377 GWe today would contribute 13% of the emissions reduction needed to limit global warming.

In the near term, small modular reactors "could extend the market for nuclear energy" and even replace coal boilers forced into closure in order to improve air quality. "Governments and industry should work together to accelerate the development of SMR prototypes and the launch of construction projects (about five projects per design) needed to demonstrate the benefits of modular design and factory assembly." In the longer term the IEA wants so-called Generation IV reactor and fuel cycle designs to be ready for deployment in 2030-40.

US Energy Information Administration

The US Energy Information Administration (EIA) publishes an annual report called International Energy Outlook (IEO).

In IEO-2021, electricity from renewables is projected to increase by more than 200% between 2020 and 2050, accounting for 56% of global electricity generation by 2050. Nuclear generation is projected to increase by 15% during this period, but relative to total generation, the share of nuclear generation would fall by one-third from 10.5% of total electricity generation in 2020 to 7.2% in 2050.

In IEO-2017, renewable energy and natural gas are forecast to be the world’s fastest growing energy sources over 2015-2040. Renewables increase at 2.8%/year, and by 2040 will provide 31% of electricity generation, equal to coal; natural gas increases by 2.1%/year. Generation from nuclear is forecast to increase by 1.6% each year. The net nuclear capacity increase is all in non-OECD countries (growth in South Korea is offset by decreases in both Canada and Europe), and China accounts for 67% of the capacity growth. By 2032, the outlook sees China surprass the United States as the country with the most nuclear generating capacity.

In IEO-2016, nuclear power and renewable energy are forecast to be the world's fastest-growing energy sources from 2012 to 2040. Renewables increase 2.6% per year, from 22% to 29% of total. Nuclear increases by 2.3% per year, from 4% of total to 6%, 2.3 PWh to 4.5 PWh. Generation from non-hydro renewables increases by 5.7% each year. Net nuclear capacity increase is all in non-OECD countries (growth in South Korea is offset by decrease in Canada and Europe), and China accounts for 61% of the capacity growth.

Institute of Energy Economics, Japan

The Asia/World Energy Outlook 2016 report by the Institute of Energy Economics, Japan (IEEJ) shows nuclear energy helping Asian countries achieve future economic growth, energy security and environmental protection. In the reference scenario, global installed nuclear generating capacity would increase from 399 GWe in 2014 to 612 GWe in 2040. Over this period, nuclear electricity generation would increase from 2535 TWh to 4357 TWh but its share of total global electricity generation will remain unchanged at around 11.5%.

In the high nuclear scenario, the IEEJ says that nuclear in effect "becomes the base power source" for many emerging countries, such as Asian and Middle Eastern countries. This scenario assumes that nuclear energy "will benefit from lower level costs, and that nuclear technology transfer will be properly made from developed countries of nuclear technology, such as Japan, to emerging countries." Under this scenario, nuclear generating capacity in Asia would increase about seven-fold between 2014 and 2040. The IEEJ notes: "The development of nuclear in the future is significantly uncertain. It is not only due to countries' or regions' circumstances of energy, economy, and development level of social infrastructure, but also a matter of international relations."

World Energy Council

In October 2016, World Energy Council (WEC) published new scenarios developed in collaboration with Accenture Strategy and the Paul Scherrer Institute as The Grand Transition. WEC notes that while global energy demand has more than doubled since 1970, the rate of growth for primary energy will now reduce and per capita demand will peak before 2030. However, electricity demand will double by 2060. Furthermore, "limiting global warming to no more than a 2°C increase will require an exceptional and enduring effort, far beyond already pledged commitments, and with very high carbon prices." WEC says global cooperation, sustainable economic growth, and technology innovation are needed to balance the energy trilemma: energy security, energy equity and environmental sustainability. Under its main scenario, where 'intelligent' and 'sustainable' economic growth models emerge as the world seeks a low-carbon future, nuclear accounts for 17% of electricity generation, or 7617 TWh, in 2060, from global installed capacity of 989 GWe. More than half of nuclear capacity additions throughout the period are in China, reaching 158 GWe in 2030 and 344 GWe in 2060. India follows China, with nuclear capacity reaching 137 GWe in 2060.

WEC’s World Energy Resources 2016 report released in the same month showed that total global renewable energy generating capacity had almost doubled over the past decade, from 1037 GWe in 2006 to 1985 GWe by the end of 2015 (61% of this hydro, 22% wind), and that renewable sources including hydro now account for 23% of total 24,098 TWh generation. The report also said: "The outlook for nuclear up to 2035 will depend largely on the success of the industry in constructing plants to agreed budgets and with predictable construction periods. It is evident in a number of countries that median construction times are stable.” Beyond 2035, the report expects fast reactors to make "an increasing contribution in a number of countries by building on the experience of operating these reactors in Russia and with developing the Generation IV prototypes, such as the Astrid reactor being designed in France.”

In November 2011 the World Energy Council (WEC) published a report: Policies for the future: 2011 Assessment of country energy and climate policies, which ranked country performance according to an energy sustainability index, meaning how well each country performs on "three pillars" of energy policy – energy security, social equity, and environmental impact mitigation (particularly low-carbon emissions), or simply environmental sustainability. The five countries with the "most coherent and robust" energy policies included large shares of nuclear energy in their electricity fuel mix. The best performers, according to the report, were: Switzerland (40% nuclear), Sweden (40% nuclear), France (75% nuclear), Germany (30% nuclear prior to reactor shutdowns earlier 2011), and Canada (15% nuclear). The report said that countries wanting to reduce reliance on nuclear power must work out how to do so without compromising energy sustainability. In Germany this would be a particular challenge without increasing the reliance on carbon-based power generation "since the renewable infrastructure currently does not have the capability to do so."

The 2013 version of this WEC World Energy Trilemma report gave top rating to Switzerland, Denmark, Sweden, the United Kingdom, and Spain as being the only countries that historically demonstrate their ability to manage the trade-offs among the three competing energy policy dimensions coherently. These all have, or depend upon, a high level of nuclear contribution. Germany had notably dropped down the list on energy security and sustainability criteria, as had France on energy security. Canada plunged from 2011 due to environmental sustainability, though at top on the other two. In the 2014 edition, WEC gave top honours to Switzerland, Sweden and Norway. Germany, Spain, and Japan dropped down the rankings.

European Commission

In December 2011 the European Commission (EC) published its Energy 2050 Roadmap, a policy paper. This was very positive regarding nuclear power and said that nuclear energy can make "a significant contribution to the energy transformation process" and is "a key source of low-carbon electricity generation" that will keep system costs and electricity prices lower. "As a large scale low-carbon option, nuclear energy will remain in the EU power generation mix." The paper analysed five possible scenarios leading to the EU low-carbon energy economy goal by 2050 (80% reduction of CO2 emissions), based on energy efficiency, renewables, nuclear power and carbon capture and storage (CCS). All scenarios show electricity will have to play a much greater role than now, almost doubling its share in final energy demand to 36%-39% in 2050. The EC high-efficiency scenario would reduce energy demand by 41% by 2050 (compared with 2005); the diversified supply technologies scenario would have a combination of high carbon prices, nuclear energy and introduction of CCS technologies; a high-renewables scenario suggests they might supply 75% of total energy supply by 2050; a "delayed CCS" scenario has nuclear power playing a major role; and a low-nuclear power scenario had coal plants with CCS providing 32% of total energy (ie 82-89% of EU electricity). The highest percentage of nuclear energy would be in the delayed CCS and diversified supply technologies scenarios, in which it would account for 18% and 15% shares of primary energy supply respectively, ie 38-50% of EU electricity. Those scenarios also had the lowest total energy costs.

World Nuclear Association Harmony programme

The World Nuclear Association has published its Harmony vision for the future of electricity, developed from the International Energy Agency’s ‘2°C Scenario' (2DS) in reducing CO2 emissions*. This IEA scenario adds 680 GWe of nuclear capacity by 2050, giving 930 GWe then (after 150 GWe retirements from 2014’s 396 GWe), providing 17% of world electricity. Harmony sets a further goal for the nuclear industry, drawing on the experience of nuclear construction in the 1980s.

* See section above on the 2015 edition of the International Energy Agency's Energy Technology Perspectives.

The Harmony goal is for the nuclear industry to provide 25% of global electricity and build 1000 GWe of new nuclear capacity by 2050. The World Nuclear Association says this requires an economic and technological level playing field, harmonized regulatory processes to streamline nuclear construction, and an effective safety paradigm which focuses safety efforts on measures that make the most difference to public wellbeing. The build schedule would involve adding 10 GWe per year to 2020, 25 GWe per year to 2025, and 33 GWe per year from then. This rate compares with 31 GWe per year in the mid-1980s. The Harmony goal is put forward at a time when the limitations, costs and unreliability of other low-carbon sources of electricity are becoming politically high-profile in several countries.


BP's latest Energy Outlook includes ‘Rapid’, ‘Net Zero’ and ‘Business-as-usual' scenarios. Growth in primary energy consumption is expected across all three scenarios, ranging from about 8% to about 25% by 2050. Growth in nuclear energy is driven by China, with generation in the country increasing by 2050 to between 3967 TWh and 4767 TWh across BP’s three scenarios. Output from renewables globally increases to about 29% of power generation by 2040.

Generation options

In electricity demand, the need for low-cost continuous, reliable supply can be distinguished from peak demand occurring over a few hours daily and able to command higher prices. Supply needs to match demand instantly and reliably over time. There are a number of characteristics of nuclear power which make it particularly valuable apart from its actual generation cost per unit – MWh or kWh. Fuel is a low proportion of power cost, giving power price stability, its fuel is on site (not depending on continuous delivery), it is dispatchable on demand, it has fairly quick ramp-up, it contributes to clean air and low-CO2 objectives, it gives good voltage support for grid stability. These attributes are mostly not monetized in merchant markets, but have great value which is increasingly recognized where dependence on intermittent sources has grown, and governments address long-term reliability and security of supply.

The renewable energy sources for electricity constitute a diverse group, from wind, solar, tidal, and wave energy to hydro, geothermal, and biomass-based power generation. Apart from hydro power in the few places where it is very plentiful, all of the renewables have limitiations, either intrinsically or economically, in potential use for large-scale power generation where continuous, reliable supply is needed.

Load curve

This diagram shows that much of the electricity demand is in fact for continuous 24/7 supply (base-load), while some is for a lesser amount of predictable supply for about three quarters of the day, and less still for variable peak demand up to half of the time.

Apart from nuclear power the world relies almost entirely on fossil fuels, especially coal, to meet demand for base-load electricity production. Most of the demand is for continuous, reliable supply on a large scale and there are limits to the extent to which this can be changed.

Natural gas is increasingly used as fuel for electricity generation in many countries. The challenges associated with transport over long distances and storage are to an extent alleviated through liquefaction. However much storage remains underground, in depleted oilfields, especially in the USA, and this can be dangerous. In 2015 the Aliso Canyon storage field in California leaked for some months, releasing about 66 tonnes of methane per hour, causing widespread evacuation and neutralising the state’s efforts to curb CO2 emissions (methane having 25 times the global warming potential).

Implications of Electric Vehicles

Future widespread use of electric vehicles, both pure electric and plug-in hybrids, will increase electricity demand modestly – perhaps up to 15% in terms of kilowatt-hours. But this increase will mostly come overnight, in off-peak demand, so will not significantly increase systems' peak capacity requirement in gigawatts. Overnight charging of vehicles will however greatly increase the proportion of that system capacity to be covered by base-load power generation – either nuclear or coal. In a typical system this might increase from about 50-60% to 70-80% of the total, as shown in the Figures below.

This then has significant implications for the cost of electricity. Base-load power is generated much more cheaply than intermediate- and peak-load power, so the average cost of electricity will be lower than with the present pattern of use. And any such major increase in base-load capacity requirement will have a major upside potential for nuclear power if there are constraints on carbon emissions. So potentially the whole power supply gets a little cheaper and cleaner, and many fossil fuel emissions from road transport are avoided at the same time.

Load curve 2

Load curve (3)

Drivers for increased nuclear capacity

The first generation of nuclear plants were justified by the need to alleviate urban smog caused by coal-fired power plants. Nuclear was also seen as an economic source of base-load electricity which reduced dependence on overseas imports of fossil fuels. Today's drivers for nuclear build have evolved:

Increasing energy demand

Global population growth in combination with industrial development will lead to strong growth in electricity consumption in the decades ahead. Besides the expected incremental growth in demand, there will be there will be the challenge of renewing a lot of existing generating stock in the USA and the EU over the same period. An increasing shortage of fresh water calls for energy-intensive desalination plants See first section above for recent projections.

Climate change

Increased awareness of the dangers and effects of global warming and climate change has led decision makers, media, and the public to realize that the use of fossil fuels must be reduced and replaced by low-emission sources of energy, such as nuclear power – the only readily available large-scale alternative to fossil fuels for production of a continuous, reliable supply of electricity.

Security of Supply

A major topic on many political agendas is security of supply, as countries realize how vulnerable they are to interrupted deliveries of oil and gas. The abundance of naturally occurring uranium makes nuclear power attractive from an energy security standpoint.


As carbon emission reductions are encouraged through various forms of government incentives and trading schemes, the economic benefits of nuclear power will increase further.

Insurance against future price exposure

A longer-term advantage of uranium over fossil fuels is the low impact that variable fuel prices have on final electricity production costs. This insensitivity to fuel price fluctuations offers a way to stabilize power prices in deregulated markets.

In practice, is a rapid expansion of nuclear power capacity possible?

It is noteworthy that in the 1980s, 218 power reactors started up, an average of one every 17 days. These included 47 in USA, 42 in France and 18 in Japan. The average power was 923.5 MWe. So it is not hard to imagine a similar number being commissioned in a decade after about 2015. 

See also the page in this series: Heavy Manufacturing of Power Plants.

Clean Air and Greenhouse Gases

On a global scale nuclear power currently reduces carbon dioxide emissions by some 2.5 billion tonnes per year (relative to the main alternative of coal-fired generation, about 2 billion tonnes relative to the present fuel mix). Carbon dioxide accounts for half of the human-contributed portion of the global warming effect of the atmosphere. Nuclear power has a key role to play in reducing greenhouse gases. 

In August 2015 the Global Nexus Initiative (GNI) was set up by the US Nuclear Energy Institute (NEI) and the Partnership for Global Security. It aims to explore the links between climate change, nuclear energy and global security challenges through a working group of 17 multidisciplinary policy experts from the non-governmental, academic and private sectors in Denmark, France, Japan, Sweden, the United Arab Emirates and the USA. The group will convene for a series of meetings and workshops, through which it aims to produce policy memoranda identifying the challenges and offering recommendations. These will feed into a cumulative report at the end of the two-year project. GNI points out that climate change, energy security and global security are all issues that cut across national borders, have significant economic and social impacts, and require input from the full spectrum of stakeholders. This means policies must be coordinated at national, regional and global levels.

See also information page on Nuclear Energy and Sustainable Development.

Heavy Manufacturing of Power Plants
Climate Change - The Science
Renewable Energy and Electricity
Nuclear Power in the World Today