A Roadmap to 100 Percent Clean Power

Carbon dioxide emissions from fossil fuel combustion are the principle culprit behind climate change, accounting for more than half of global carbon emissions. If humankind is to tackle the climate challenge it needs to decarbonize electricity and transportation systems. Decarbonizing the electricity system in particular means shifting toward clean, renewable energy sources such as wind and solar. While vast technological advances in recent decades have made this transition an economic and technological possibility, significant challenges remain.
 
In a recent paper in the journal Energy Policy, Georgios Papaefthymiou and Ken Dragoon, researchers from consulting companies in Germany and Oregon, provided a detailed outline for this transformation. They offered an overview of the policies, and presented the technological and institutional changes necessary to create an almost 100-percent clean power system. To help guide policymakers, they grouped their results in three development phases: initial, medium-term, and long-term phases.
 
The initial phase, they write, should include the technological and policy changes necessary to achieve the transition to 100-percent clean power. In this development phase, renewables account for up to 10 percent of electricity generation. The steps required here will lead to relatively mild changes in conventional power system operations and structures. Two types of action guide this phase: improving technologies and implementing favorable policies. Utilities and energy infrastructure developers need to minimize the cost of integrating variable renewable energy sources into the power system, they write. One way to achieve this would be to provide more precise energy demand forecasts. That, in turn, can reduce the need for reserve energy and significantly reduce costs. Secondly, policymakers need to phase out economic incentives that favor fossil fuel production.
 
The middle phase of the transition is where the bulk of the technological and policy changes must occur to scale up renewable electricity generation. In this phase, renewable energy provides up to 50 percent of the electricity supply. A key priority during this phase will be policies that encourage energy efficiency. The study also describes how utilities will need to invest in technological innovations that would provide a more reliable electricity grid, for example, through the improvement of transmission and distribution lines. Policies will also need to promote the development of smart grids, or remote controlled, automated systems that can allow utilities to more precisely manage electricity supply and demand in real time.
 
In the long-term phase, the researchers write, policymakers can exploit the last sources of efficiencies in the power system. One crucial strategy here will be to promote the most cost-effective energy storage solutions. Policymakers will need to provide incentives for industry to electrify sectors that have not traditionally depended on electricity for their energy uses, such as the transportation system and several industrial processes. A key challenge will be to efficiently use the surplus electricity that renewable technologies such as solar photovoltaics (PVs) generate when sunlight is abundant. Another important consideration will be to make full use of existing transmission infrastructure so as to not burden ecosystems with too many new constructions.
 
The transition to 100-percent renewable energy power systems will require a wide range of policy, technological, and institutional developments. The intricacy of this issue is underscored by the sheer number of needed changes both in terms of technological improvements and policy directions. Studies like this can help policymakers design appropriate strategies by outlining key considerations. While the transition to a fully renewable power system will likely be a decades-long, incremental process, all stakeholders need to start to address the complex challenges ahead.
 
The research was funded by the European Copper Institute as a part of its Power System Flexibility Roadmap project.