Adopting sustainable technologies: New methods for a new world

The transition to a sustainable energy system will require profound changes across almost every aspect of society, from individual choices to government policies. To aid this transition the IIASA Energy Program (ENE) has worked to enhance global energy-economy models, providing insights into the investments needed to deploy a large share of wind and solar technologies in power systems, and the role of consumer preferences in adopting sustainable transport.

Renewable energy technologies such as wind turbines and solar photovoltaics are deemed essential to creating a sustainable energy system; however, they can be intermittent and it is not possible to adjust their power output to order. This means that power systems with significant deployment of this “variable renewable energy” will likely need more backup capacity to ensure peak demand, more flexibility to address increased fluctuations in power supply, and more energy storage or power-to-gas technology to absorb the excess energy generated at times.

The costs of implementing these changes may be significant, and assessments of low-carbon futures must account for them. However, global energy-economy models are not detailed enough to directly assess impacts due to mismatches between electricity supply and demand that can occur from one minute to the next. To address this, ENE researchers used the Model for Energy Supply Strategy Alternatives and their General Environmental Impact (MESSAGE) to simulate the impacts and costs of the integration of variable renewable energy, providing estimates of the magnitude and duration of the load that must be provided by technologies that can adjust their power output to order.

The model indicates that there will be a significant reduction in the use of non-renewable power plants with a diminishing role for traditional generators, such as nuclear and coal, and a transition to more flexible technologies. The results also highlight the importance of electricity storage and hydrogen electrolysis in deploying variable renewable energy. Despite better representation of integration impacts and costs, wind and solar technologies remain competitive with other low-carbon options and climate change mitigation drives the share of variable renewable energy technologies to 53-89% of electricity generation in 2100 across the models [2][3].

ENE researchers have also examined the adoption of sustainable technologies in the transport sector, which is responsible for about a quarter of all energy-related CO2 emissions. Widespread substitution of conventional vehicles with those powered by low-carbon sources of electricity or hydrogen is seen as essential to limit global warming to 2°C. One critical determinant for this transition will be the consumer preferences for which cars to use.

Again, global energy-economy models fall somewhat short here, as they are limited in their representation of consumer decision-making. To improve the situation, ENE researchers led the first global model comparison exercise to date dedicated exclusively to realistically representing consumer behavior in long-term energy transitions.

Their findings emphasize two key points. First, strategies and policies explicitly targeting consumer attitudes toward alternative fuel vehicles are necessary to drive widespread adoption of these technologies; and second, carbon pricing is needed to ensure that the electricity and hydrogen used to power these vehicles are derived from low-carbon sources [4].

In addition to this work, ENE has taken a leading role in scaling up the International Transport and Energy Modeling Consortium, a group of global transportation modelers and analysts from academia, government, industry, and non-governmental organizations. ENE co-organized the consortium’s second workshop in 2016 and preliminary results were presented at UN Climate Change Conference COP22 in Marrakech.


[1] Johnson N, Strubegger M, McPherson M, Parkinson S, Krey V, & Sullivan P (2016). A reduced-form approach for representing the impacts of wind and solar PV deployment on the structure and operation of the electricity system. Energy Economics

[2] Pietzcker RC, Ueckerdt F, Carrara S, Sytze de Boer H, Després J, Fujimori S, Johnson N, Kitous A, et al. (2016). System integration of wind and solar power in Integrated Assessment Models: A cross-model evaluation of new approaches. Energy Economics

[3] Luderer G, Pietzcker RC, Carrara S, de Boer H-S, Fujimori S, Johnson N, Mima S, & Arent D (2017). Assessment of wind and solar power in global low-carbon energy scenarios: An introduction. Energy Economics

[4] McCollum DL, Wilson C, Bevione M, Carrara S, Edelenbosch OY, Emmerling J, Guivarch C, Karkatsoulis P et al. (2017). The role of consumer preferences and climate policies in shaping the global private vehicle market (submitted)


  • Charlie Wilson and Hazel Pettifor, University of East Anglia
  • Michela Bevione, Samuel Carrara, and Johannes Emmerling, Fondazione Eni Enrico Mattei and Centro Euro-Mediterraneo sui Cambiamenti Climatici
  • Oreane Y. Edelenbosch and Detlef P. van Vuuren, PBL Netherlands Environmental Assessment Agency
  • Celine Guivarch and Eoin Ó Broin, Centre International de Recherche sur l’Environnement et le Développement
  • Panagiotis Karkatsoulis and Leonidas Paroussos, National Technical University of Athens
  • Ilkka Keppo and Baltazar Solano Rodriguez, University College London
  • Zhenhong Lin, Oak Ridge National Laboratory
  • Kalai Ramea and Lew Fulton, University of California, Davis
  • Fuminori Sano, Research Institute of Innovative Technology for the Earth
  • Sonia Yeh, Chalmers University of Technology
  • Gunnar Luderer, Robert Pietzcker, Falko Ueckerdt, Potsdam Institute for Climate Impact Research
  • Yvonne Scholz, German Aerospace Center
  • Harmen Sytze de Boer, PBL Netherlands Environmental Assessment Agency
  • Samuel Carrara, Fondazione Eni Enrico Mattei
  • Shinichiro Fujimori, National Institute for Environmental Studies
  • Douglas Arent, Patrick Sullivan, National Renewable Energy Laboratory
  • Silvana Mima, Jacques Despres, Université Grenoble Alpes