Climate change mitigation potential of energy technologies

Here we translate broad, high-level climate targets into practical performance targets for energy technologies in terms of their cost and carbon intensities. We also examine how disaggregated, segmental policies that separately target supply-side technologies and demand-side efficiency might be used to control emissions.

Performance intensity targets for cost and carbon intensity of energy: In this work we present a new, simple model for evaluating energy-supply technologies and their improvement trajectories against climate-change mitigation goals. We define a target for technology performance in terms of the carbon intensity of energy consistent with emissions reduction goals and varied demand levels. Because the cost of energy determines the level of adoption, we then compare supply technologies to one another and to this target based on their position on a cost and carbon trade-off curve—and how the position changes over time. The model can be used to quantify the carbon intensity and associated cost of energy that is required to be consistent with climate goals. We show how these performance targets and the resulting energy supply portfolios depend on energy demand levels, illustrating the relationship between changes to supply-side energy technologies and demand-side efficiency in meeting climate goals.

  • Trancik JE, Cross-Call D, Energy technologies evaluated against climate targets using a cost and carbon tradeoff curve, Environmental Science & Technology, 2013, Vol. 47, pp. 6673-6680 pdf.

Segmental approaches to controlling emissions: Resistance to adopting a cap on greenhouse gas emissions internationally, and across various national contexts, has encouraged alter- native climate change mitigation proposals. These proposals include separately targeting clean energy uptake and demand-side efficiency, an approach to climate change mitigation that we characterize as segmental and technology-centered. A debate has ensued on the detailed implementation of these policies in particular contexts, but less attention has been paid to the general factors determining the effectiveness of a segmental approach to emissions reduction. We address this topic by probing the interdependencies of segmental policies and their collective ability to control emissions. First, we show how the set of suitable energy technologies depends on demand-side efficiency, and changes with the stringency of climate targets. Second, we quantify the enhanced propensity to exceed any intended emissions target with this approach, even if goals are set on both the supply and demand side, due to the multiplicative accumulation of emissions error. Third, we discuss why despite these risks, the enhanced planning capability of a segmental approach may help counteract growing infrastructural inertia. The emissions reduction impediment due to infrastructural inertia is significant in each of the greatest emitters: China, the US and Europe. Commonly cited climate targets are still within reach but, as we show, would require immediate and major reductions in the carbon intensity of new power plants built in these regions over the next two decades.

  • Trancik JE, Chang MT, Karapataki C, Stokes LC, Effectiveness of a segmental approach to emissions control, Environmental Science & Technology, 2014, Vol. 48, pp. 27-35 link.

Evaluating transportation technologies against climate policy targets: Meeting global climate change mitigation goals will likely require that transportation-related greenhouse gas emissions begin to decline within the next two decades and then continuously fall. A variety of vehicle technologies and fuels are commercially available to consumers today that can reduce the emissions of the transportation sector. Yet what are the best options, and do any suffice to meet climate policy targets? Here we examine the costs and carbon intensities of 125 light-duty vehicle models on the U.S. market today and evaluate these models against U.S. emissions reduction targets for 2030, 2040 and 2050 that are compatible with the goal of limiting mean global temperature rise to 2 degrees celsius above preindustrial levels. Our results show that consumers are not required to pay more for a low-carbon-emitting vehicles. Across the diverse set of vehicle models and powertrain technologies examined, a clean vehicle if usually a low-cost vehicle. Although the average carbon intensity of vehicles sold in 2014 exceeds the climate target for 2030 by more than 50%, we find that most hybrid and battery electric vehicles available today meet this target. By 2050, only electric vehicles supplied with almost completely carbon-free electric power are expected to meet climate-policy targets.

  • Miotti M, Supran GJ, Kim EJ, Trancik JE, Personal vehicles evaluated against climate change mitigation targets, Environmental Science & Technology, 2016, Vol. 50, pp. 10795-10804 link.