Structural evolution of the UK electricity system in a below 2°C World

We employ an electricity system model to determine the least-cost transition necessary to meet a given carbon dioxide removal (CDR) burden in the UK. The results show that, while sufficient in the medium term, a system dominated by intermittent renewable energy technologies (IRES) cannot deliver CDR at the scale required in a cost-effective manner. The marginal value of IRES for climate change mitigation diminishes with time, especially in the context of the Paris Agreement. Deeper decarbonization precipitates a resurgence of thermal generation from bioenergy and gas (with carbon capture and storage) and nuclear. Such a system is inherently centralized and will require maintenance of existing transmission and distribution infrastructure. Current policy direction, however, encourages the proliferation of renewables and decentralization of energy services. To avoid locking the power system into a future where it cannot meet climate change mitigation ambitions, policy must recognize and adequately incentivize the new technologies (CCS) and services (CDR) necessary

Higher carbon prices on emissions alone will not deliver the Paris agreement

Limiting global warming to 2°C by 2100 requires anthropogenic CO2 emissions to reach zero by 2070 and become negative afterwards; therefore, large-scale carbon dioxide removal (CDR) from the atmosphere is critical. We investigate the effectiveness of carbon prices in achieving the deep decarbonization needed in the power system. We find that if only CO2 emitters are penalized, increasing prices to the social cost of carbon is sufficient to achieve a decarbonized system in the medium-term but not maintain it in the long-term. Unless carbon pricing mechanisms are adapted to remunerate CDR services, CDR technologies are not deployed. Incentivizing CDR could mean that lower levels of carbon taxation are needed to meet the Paris Agreement, which in turn lowers electricity costs. However, the deployment of CDR technologies could prolong the use of unabated fossil fuels in a carbon-constrained system, therefore, disincentives must be implemented to prevent this moral hazard from manifesting

The implications of delivering the UK’s Paris Agreement commitments on the power sector

Through the 2015 Paris Agreement, the UK committed to keeping average global temperature rise to “well below 2 °C”. Integrated Assessment Models show that this will require extensive greenhouse gas removal (GGR) from the atmosphere. For the EU, it is estimated that 20–70 GtCO2 of cumulative GGR by 2100 is required, all from bioenergy with carbon capture and storage (BECCS). Depending on how the burden of GGR is shared, the UK would need to remove 2–6 GtCO2 from the atmosphere. We apply a power systems planning model to determine how the electricity system would need to transition from 2015 to 2100 to meet the UK’s Paris Agreement commitments. We find that until 2050, increased penetration of renewables, interconnection capacity and energy storage, alongside 15–17 GW of CCGT−CCS, is sufficient to stay on the required emissions trajectory. Between 2050 and 2100, however, the deployment of 7–26 GW of BECCS and 2–5 GW of direct air capture and storage (DACS) is crucial to provide the GGR required. A Paris-compliant UK electricity system will require £620–700 billion of capital and operational expenditure by 2100, 3–16% greater than the cost of achieving a decarbonised system. For the upper-bound GGR target, local biomass supply is insufficient, so imports are necessary. By 2100, up to 26% of annual demand is met by imported biomass. Such heavy dependence on imports may raise energy security concerns. Also, should biomass imports not be available in the required quantities, alternative (and more expensive) GGR methods will be necessary thereby increasing the cost of delivering a Paris-compliant system

Negative emissions: priorities for research and policy design

The large-scale removal of carbon dioxide from the atmosphere is likely to be important in maintaining temperature rise “well below” 2°C, and vital in achieving the most stringent 1.5°C target. Whilst various literature efforts have estimated the global potential of carbon dioxide removal (CDR) for a range of technologies with different degrees of certainty, regional bottlenecks for their deployment remain largely overlooked. Quantifying these barriers, through national and local case studies, rather than with aggregated approaches, would guide policy and research, as well as investments, toward regions that are likely to play a prominent role in CDR deployment. Five CDR technologies—including afforestation/reforestation, bioenergy with carbon capture and storage, biochar, direct air capture and enhanced weathering—are compared in this work. We discuss main technical, socio-economic and regulatory bottlenecks that have been scarcely investigated at regional level, and provide directions for further research. We identify the availability of accessible land, water, low carbon energy and CO2 storage as key regional drivers and bottlenecks to most CDR technologies. We discuss the caveats in CO2 accounting in assessing the performance of each technology, and the need for an international regulatory framework which captures these differences. Finally, we highlight the social, economic and political drivers which are central in unlocking the large scale deployment of CDR technologies, in a cost attractive, socially acceptable and politically achievable way

Equity in allocating carbon dioxide removal quotas

The first nationally determined contributions to the Paris Agreement include no mention of the carbon dioxide removal (CDR) necessary to reach the Paris targets, leaving open the question of how and by whom CDR will be delivered. Drawing on existing equity frameworks, we allocate CDR quotas globally according to Responsibility, Capability and Equality principles. These quotas are then assessed in the European Union context by accounting for domestic national capacity of a portfolio of CDR options, including bioenergy with carbon capture and storage, reforestation and direct air capture. We find that quotas vary greatly across principles, from 33 to 325 GtCO2 allocated to the European Union, and, due to biophysical limits, only a handful of countries could meet their quotas acting individually. These results support strengthening cross-border cooperation while highlighting the need to urgently deploy CDR options to mitigate the risk of failing to meet the climate targets equitably