A wide range of regions, nations and respected organisations have created net-zero strategies and pathways, but on what do they agree and disagree? Dolf Gielen, Asami Miketa, Ricardo Gorini and Pablo Carvajal at IRENA have done a meta-analysis of 18 recent energy transition scenarios to find out. There is consensus over the main strategies: renewable power generation, and the direct and indirect electrification of end-use sectors – these account for two-thirds to three-quarters of emissions reductions. Opinions diverge over the future role of bioenergy and CO2 capture (CCS, CCU and CDR) – these account for the rest. The good news is that we agree on most of what we need to do, though strategies differ and policy frameworks must be enabled. The authors draw our attention to six targets to focus on: energy intensity, renewables share in primary energy, renewable power generation, EV sales, hydrogen demand, biomass, and reducing global emissions by 50% by 2030. The authors stress that the future can surprise us (technology progress, enabling frameworks, social acceptance, etc.), so strategies must be updated regularly to optimise pathways. For example, the continued decline in renewable energy costs has left the IPCC SR1.5 report, compiled a few years ago, outdated. That’s no good for optimising vitally important decisions taken now.
The world has committed to decarbonisation, but the pathways how to get there are still uncertain. The climate summit (April 22nd & 23rd) organised by President Biden has yielded increasing climate ambitions. COP26 in November may provide additional clarity on where we are collectively heading. The IPCC states that the world will need to fully curb its carbon emissions by 2050 and by 41% to 58% in 2030, compared to 2010 levels, for limited or no overshoot of a 1.5°C global temperature rise by 2100.
In fact, emissions have increased by about 15% since 2010. Energy and industrial emissions reached a level of 37 Gt in 2019, and although they dipped in 2020 because of the COVID-19 crisis, they were back to the previous year’s level in the last months of 2020.
As the direction of energy transition is essentially the same for 1.5 degrees and 2 degrees (only differentiated by the pace of emission reductions), all efforts in the coming years will contribute to limit climate change in the long run.
China, U.S., India, EU27+UK
Addressing that challenge will require concerted action by all countries, but the actions of a few countries and regions are critical. China, the United States, India and EU27+UK account for two-thirds of global emissions (see Figure 1). Together they will determine whether we get on a pathway consistent with 1.5°C degrees.
Figure 1: Fossil CO2 emissions of major economies. / Source: IRENA, based on JRC, 2020
Six targets to focus on
In March, the International Renewable Energy Agency (IRENA) launched its World Energy Transitions Outlook. The report provides details on reducing global energy and CO2 emissions to net-zero between now and 2050 in line with limiting warming to 1.5°C. The energy transition that is required is very profound:
- Annual energy intensity improvements must rise from 1.2% in recent years to around 3%. Renewable power, electrification and circular economy have a crucial role to play in reducing the energy intensity, on top of the conventional energy efficiency technologies;
- Annual renewable energy share in primary energy needs to reach 74%, accelerating the growth in the share 8-fold from recent years;
- Renewable power generation needs to grow from 2,500 to 27,500 GW by 2050, a growth of 800 GW per year, a 4-5 fold increase of the annual capacity additions from recent years;
- Electric vehicle sales need to grow from 4% to 100% of all vehicle sales, and electric vehicle stock needs to grow from 7 million in 2020 to 1.8 billion in 2050;
- Hydrogen demand needs to grow from 120 Mt per year to 613 Mt in 2050, a fivefold increase. On average, 160 GW of electrolyser capacity must be installed every year between now and 2050;
- The total primary supply of biomass will need to increase to just over 150 EJ, nearly a tripling of primary biomass use in 2018;
- To stay within the remaining carbon budget for 1.5°C degrees, global emissions need to fall by around 50% between now and 2030; Significant structural changes and behavioural change is needed, on top of the technological transitions.
The main strategies are converging
The energy transition outlook for 2050 is uncertain. Even if net-zero emissions are taken as a given, there are multiple pathways to get there. However, the understanding of how to get there seems to be converging. IRENA has assessed 18 recent scenario studies, including: the IRENA 1.5°C Scenario (1.5-S) from the World Energy Transitions Outlook launched in March 2021, the IEA net-zero scenario launched in May 2021, four studies for the United States, five for China, five for the European Union and two for India. The country and EU studies combined cover around two-thirds of global energy and process CO2 emissions.
A set of 32 indicators was developed to characterise the scenarios. Table 1 provides a summary of the most important findings. For each country and region, the range of findings is shown. These are benchmarked to 1.5°C world studies from IRENA, the IEA and the IPCC IAM literature.
The findings show that:
- There is consensus across all regions and all studies that renewables have a vital role in the energy transition. As witnessed by the renewable energy share in primary supply that grows to between 48% and 94% of primary energy supply for all 18 studies, compared to 15% of current primary energy supply. Especially the renewable share in power supply is projected to grow significantly, between 61% and 95% across all 18 studies.
- Electrification of final energy use has a pivotal role to play, with a range in electricity share in final energy from 46% to 73% in final energy use.
- Hydrogen has a significant role to play across most studies.
- There is less consensus regarding the role of bioenergy and the CO2 management options CCS (underground storage) and CCU (use of CO2 to manufacture materials, fuels etc.). While the IEA and IRENA studies suggest a significant role (notably for CCS), the country and EU studies suggest a more limited role.
- Less use of CCS and biomass is in most cases compensated by generous assumptions regarding carbon dioxide removal (CDR), primarily based on land-use change and forestry.
The results show that the major trends are the same across all scenarios that were identified. The fact that countries and regions with very different economic structure and different resource endowment show similar strategies is significant.
Strategies must and will evolve
At the same time, the findings reveal that scenario studies for specific geographies show a range in terms of the absolute importance of specific strategies. There is no single “true” scenario of what 2050 will look like. Technology progress, enabling frameworks and social acceptance, amongst others, will determine the transition pathway that will emerge. Therefore, it is essential to conduct scenario studies regularly and adjust strategies to reflect the latest insights.
The Long-term Energy Scenarios Initiative and Network (LTES) is operated by IRENA for that purpose. It is a platform that has been set up to enhance the effective use of scenarios for energy transition policymaking. The effective use of national scenarios also requires that they are developed to meet the purpose, and certain methodologies and planning governance structures are to be followed. A set of guidelines has been developed on how policymakers can strengthen their use of scenarios based on the LTES members’ practices. The initiative is part of the Clean Energy Ministerial, while the network is open to all IRENA members.
Table 1: Indicators of energy transition pathways 2050 / IRENA analysis [links to sources given at end of article] [* Primary bioenergy accounting rules for IEA and IRENA differ therefore the gap is smaller in terms of practical biomass use]
IPCC literature needs updating
Also, a marked difference emerges between the IPCC IAM literate for 1.5°C by 2050 scenarios and national scenarios, where the IPCC IAMs banks much more on biomass use (150 EJ [median]) and CCS use (15 Gt [median]), and less on hydrogen (126 Mt [median]) and renewable power (60%-80% solar and wind). The reason is that the IPCC SR1.5 report was compiled a few years ago based on older literature (outdated renewable energy cost assumptions). This body of work does not capture the recent rapid progress in the field of renewable energy and electrification. So, there is an urgent need to update this body of work with latest insights.
Agreement, but also uncertainty
The key strategies identified in the IRENA 1.5°C scenario are robust (renewable power, direct and indirect electrification). There is some uncertainty regarding the future role of biomass and carbon dioxide management options. Overall this means around two thirds to three quarters of the findings on how to achieve emissions mitigation are robust while a quarter to a third are relatively uncertain.
Whereas national studies emphasise land use change and forestry (other CDR), the global studies are silent. What plays a role is these global studies already assume global net zero emissions from LULUCF (Land Use, Land-Use Change and Forestry). So, while individual countries may claim a significant CDR gain this may not add up on a global scale. Also, it is important to point out that net zero may imply growth of emissions in developing countries which would need compensation by net negative emissions in developed countries. These two aspects mean that even the very ambitious national plans discussed may fall short of a global 1.5 C pathway. Such discrepancy has been noted previously.
Finally, the scenario analysis has shown that specific aspects are often unclear, for example inclusion of process emissions or emissions related to non-energy use and waste processing. While these issues are of secondary importance in a 2030 timeframe, they can become important in a 2050 context. Development of more robust scenario comparison frameworks is therefore recommended.
Overall the priority now is to move from analysis to action. The pathway is clear, it’s the enabling frameworks that require attention.
***
Dolf Gielen is the Director of the Innovation and Technology Center in Bonn, IRENA
Asami Miketa is a Senior Programme Officer, Power Sector Investment Planning, IRENA
Ricardo Gorini is the Senior Programme Officer, Renewable Energy Roadmaps (REmap), IRENA
Pablo Carvajal is a Programme Officer – Clean Energy Transition Scenarios, IRENA
REFERENCES for Table 1:
2] https://netzeroamerica.princeton.edu/?explorer=pathway&state=national&table=ref&limit=200
3] https://olyclimate.files.wordpress.com/2013/09/e997d-350ppmpathwaysfortheunitedstates.pdf
4] https://www.unsdsn.org/Zero-Carbon-Action-Plan
6] https://www.thinkchina.ku.dk/documents/CREO-2019-EN-Final-0316.pdf
7] https://rmi.org/wp-content/uploads/2019/11/china_2050_fully_developed_rich_zerocarbon_economy.pdf
8] https://onlinelibrary.wiley.com/doi/epdf/10.1111/aepr.12330
13] https://www.greens-efa.eu/en/article/document/the-vision-scenario-for-the-european-union-7659
17] https://www.iea.org/reports/net-zero-by-2050
18] https://irena.org/publications/2021/March/World-Energy-Transitions-Outlook
19] https://www.nature.com/articles/s41558-018-0091-3
21] https://tntcat.iiasa.ac.at/SspDb/dsd?Action=htmlpage&page=40
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