An energy transition (or energy system transformation) is a major structural change to energy supply and consumption in an energy system. Currently, a transition to sustainable energy is underway to limit climate change. Most of the sustainable energy is renewable energy. Therefore, another term for energy transition is renewable energy transition. The current transition aims to reduce greenhouse gas emissions from energy quickly and sustainably, mostly by phasing-down fossil fuels and changing as many processes as possible to operate on low carbon electricity. A previous energy transition perhaps took place during the Industrial Revolution from 1760 onwards, from wood and other biomass to coal, followed by oil and later natural gas.
Over three-quarters of the world's energy needs are met by burning fossil fuels, but this usage emits greenhouse gases. Energy production and consumption are responsible for most human-caused greenhouse gas emissions. To meet the goals of the 2015 Paris Agreement on climate change, emissions must be reduced as soon as possible and reach net-zero by mid-century. Since the late 2010s, the renewable energy transition has also been driven by the rapidly falling cost of both solar and wind power. After 2024, clean energy is cheaper than ever. Global solar module prices fell 35 percent to less than 9 cents/kWh. EV batteries saw their best price decline in seven years. Another benefit of the energy transition is its potential to reduce the health and environmental impacts of the energy industry.
Heating of buildings is being electrified, with heat pumps being the most efficient technology by far. To improve the flexibility of electrical grids, the installation of energy storage and super grids are vital to enable the use of variable, weather-dependent technologies. However fossil-fuel subsidies are slowing the energy transition.
Energy transitions have varied environmental and social effects, as they can create both burdens and benefits for different communities. Concepts such as energy justice and energy democracy emphasise the importance of equitable distribution of energy costs and benefits, inclusive decision-making processes, and the recognition of historically marginalised groups in energy transitions.
Definition
An energy transition is a broad shift in technologies and behaviours that are needed to replace one source of energy with another. A prime example is the change from a pre-industrial system relying on traditional biomass, wind, water and muscle power to an industrial system characterized by pervasive mechanization, steam power and the use of coal.
The IPCC does not define energy transition in the glossary of its Sixth Assessment Report but it does define transition as: "The process of changing from one state or condition to another in a given period of time. Transition can occur in individuals, firms, cities, regions and nations, and can be based on incremental or transformative change."IPCC, 2022: Annex I: Glossary [van Diemen, R., J.B.R. Matthews, V. Möller, J.S. Fuglestvedt, V. Masson-Delmotte, C. Méndez, A. Reisinger, S. Semenov (eds)]. In IPCC, 2022: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [P.R. Shukla, J. Skea, R. Slade, A. Al Khourdajie, R. van Diemen, D. McCollum, M. Pathak, S. Some, P. Vyas, R. Fradera, M. Belkacemi, A. Hasija, G. Lisboa, S. Luz, J. Malley, (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA. doi: 10.1017/9781009157926.020
Development of the term
After the 1973 oil crisis, the term energy transition was coined by politicians and media. It was popularised by US President Jimmy Carter in his 1977 Address on the Nation on Energy, calling to "look back into history to understand our energy problem. Twice in the last several hundred years, there has been a transition in the way people use energy ... Because we are now running out of gas and oil, we must prepare quickly for a third change to strict conservation and to the renewed use of coal and to permanent renewable energy sources like solar power." The term was later globalised after the 1979 second oil shock, during the 1981 United Nations Conference on New and Renewable Sources of Energy.
From the 1990s, debates on energy transition have increasingly taken climate change mitigation into account. Parties to the agreement committed "to limit global warming to "well below 2 °C, preferably 1.5 °C compared to pre-industrial levels". This requires a rapid energy transition with a downshift of fossil fuel production to stay within the carbon emissions budget.
In this context, the term energy transition encompasses a reorientation of energy policy. This could imply a shift from centralized to distributed generation. It also includes attempts to replace overproduction and avoidable energy consumption with energy-saving measures and increased efficiency.Louis Boisgibault, Fahad Al Kabbani (2020): Energy Transition in Metropolises, Rural Areas and Deserts. Wiley - ISTE. (Energy series) .
The historical transitions from locally supplied wood, water and wind energies to globally supplied fossil and nuclear fuels has induced growth in end-use demand through the rapid expansion of engineering research, education and standardisation. The mechanisms for the whole-systems changes include new discipline in Transition Engineering amongst all engineering professions, entrepreneurs, researchers and educators.
However it has been argued that the term is a mere slogan and that rather than transitioning, as of 2024, use of all forms of primary energy has increased.
Examples of past energy transitions
Historic approaches to past energy transitions are shaped by two main discourses. One argues that humankind experienced several energy transitions in its past, while the other suggests the term "energy additions" as better reflecting the changes in global energy supply in the last three centuries.
The chronologically first discourse was most broadly described by Vaclav Smil. It underlines the change in the energy mix of countries and the global economy. By looking at data in percentages of the primary energy source used in a given context, it paints a picture of the world's energy systems as having changed significantly over time, going from biomass to coal, to oil, and now a mix of mostly coal, oil and natural gas. Until the 1950s, the economic mechanism behind energy systems was local rather than global.
The second discourse was most broadly described by Jean-Baptiste Fressoz. It emphasises that the term "energy transition" was first used by politicians, not historians, to describe a goal to achieve in the future – not as a concept to analyse past trends. When looking at the sheer amount of energy being used by humankind, the picture is one of ever-increasing consumption of all the main energy sources available to humankind. For instance, the increased use of coal in the 19th century did not replace wood consumption, indeed more wood was burned. Another example is the deployment of passenger cars in the 20th century. This evolution triggered an increase in both oil consumption (to drive the car) and coal consumption (to make the steel needed for the car). In other words, according to this approach, humankind never performed a single energy transition in its history but performed several energy additions.
Contemporary energy transitions differ in terms of motivation and objectives, drivers and governance. As development progressed, different national systems became more and more integrated becoming the large, international systems seen today. Historical changes of energy systems have been extensively studied. While historical energy changes were generally protracted affairs, unfolding over many decades, this does not necessarily hold true for the present energy transition, which is unfolding under very different policy and technological conditions.
For current energy systems, many lessons can be learned from history. The need for large amounts of firewood in early industrial processes in combination with prohibitive costs for overland transportation led to a scarcity of accessible (e.g. affordable) wood, and eighteenth century glass-works "operated like a forest clearing enterprise". When Britain had to resort to coal after largely having run out of wood, the resulting fuel crisis triggered a chain of events that two centuries later culminated in the Industrial Revolution. Similarly, increased use of peat and coal were vital elements paving the way for the Dutch Golden Age, roughly spanning the entire 17th century. Another example where resource depletion triggered technological innovation and a shift to new energy sources is 19th century whaling: whale oil eventually became replaced by kerosene and other petroleum-derived products. To speed up the energy transition it is also conceivable that there will be government buyouts or bailouts of coal mining regions.
Drivers for current energy transition
Climate change mitigation and co-benefits
A rapid energy transition to very-low or zero-carbon sources is required to mitigate the effects of climate change.M. Pathak, R. Slade, P.R. Shukla, J. Skea, R. Pichs-Madruga, D. Ürge-Vorsatz,2022: Technical Summary. In: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [P.R. Shukla, J. Skea, R. Slade, A. Al Khourdajie, R. van Diemen, D. McCollum, M. Pathak, S. Some, P. Vyas, R. Fradera, M. Belkacemi, A. Hasija, G. Lisboa, S. Luz, J. Malley, (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA. doi: 10.1017/9781009157926.002.UN Energy (2021) Theme Report on Energy Transition towards the Achievement of SDG 7 and Net-Zero Emissions Coal, oil and gas combustion account for 89% of emissions and still provide 78% of primary energy consumption.
Despite the knowledge about the risks of climate change and the increasing number of climate policies adopted since the 1980s, however, energy transitions have not accelerated towards decarbonization beyond historical trends and remain far off track in achieving climate targets.
The deployment of renewable energy can generate co-benefits of climate change mitigation: positive socio-economic effects on employment, industrial development, health and energy access. Depending on the country and the deployment scenario, replacing coal power plants can more than double the number of jobs per average MW capacity. The energy transition could create many green jobs, for example in Africa. The costs for retraining workers for the renewable energy industry was found to be trivial for both coal in the U.S. and oil sands in Canada. The latter of which would only demand 2–6% of federal, provincial, and territorial oil and gas subsidies for a single year to be reallocated to provide oil and gas workers with a new career of approximately equivalent pay. In non-electrified rural areas, the deployment of solar mini-grids can significantly improve electricity access.
Employment opportunities by the green transition are associated with the use of renewable energy sources or building activity for infrastructure improvements and renovations.
Energy security Another important driver is energy security and independence, with increasing importance in Europe and Taiwan because of the 2022 Russian invasion of Ukraine. Unlike Europe's 2010s dependence on Russian gas, even if China stops supplying solar panels those already installed continue generating electricity. Militaries are using and developing electric vehicles, particularly for their stealthiness, but not tanks. As of 2023 renewable energy in Taiwan is far too small to help in a blockade.