The increasing understanding of the physics of climate change underlines the urgent need to decarbonize our society. The recent climate negotiations in Paris have been a clear signal that the international community of states acknowledges this need. The political representatives of 177 countries agreed by mutual consent to keep the increase of the global average temperature below 2°C. Keeping the temperature rise within this 2°C limit will require reduction in fossil-fuel emissions drastically. As fossil fuels currently form the backbone of the global energy supply, this is a challenging task.

There is hope, however, that renewable technologies will help overcome this task and free our society from its dependence on fossil fuels. Over the last decade, increasing sums of money have been invested in the renewable energy sector and in 2014 the investments made in the renewable sector equalled those made in the fossil fuel sector. Along with an increase in investment, renewable energy technologies, and in particular wind power and solar photovoltaics, experienced a perceptible fall in cost. Moreover, it is expected that this trend will increase in the future and will gradually close the existing cost gap to fossil fuel technologies.

While the recent, and projected, development of renewables gives reason to hope that it is possible to move away from fossil fuels, there are also concerns about a large-scale uptake of renewable energies. One of the main concerns relates to the intermittent production of power from renewables. As both wind and sun conditions vary across time and space, it is feared that high shares of renewables will require costly reserve and balancing capacities, or even more costly storage facilities, in order to provide constant base load supply.

Alexander MacDonald and colleagues from University of Colorado Boulder show, however, that this fear is not appropriate in all cases. In their study they found that if renewable energy technologies are connected across large areas via transmission lines, regional weather differences balance each other out and reduce the need for fossil-fuel based reserve capacities and energy storage facilities. More specifically, they show that if high-voltage direct-current transmission lines would interconnect the whole area of continental US, renewables may reduce up to 80 percent of carbon emissions without any new reserve capacities or storage facilities, and, what is even more surprising, without raising the costs of electricity. While MacDonald and colleagues did not consider the electrification of other sectors (i.e. mobility sector), Jacobson et al. from University of Stanford calculated that by 2050 renewables could even produce enough power to meet the US end-use energy demand of all sectors at reasonable costs.

However, while both studies suggest that it is technically and economically feasible to deploy renewable energy technologies on a large scale, they neglect social, cultural and political forces that influence the transition towards renewable energy systems. Technical and economic feasibility is a necessary but not sufficient condition for the successful roll-out of renewable energy.

Take, for example, the required extension of trans-regional transmission lines. Building a power grid system large enough for an optimal use of renewables would pose enormous political challenges for many regions of the world. Moreover, building new high-voltage transmission lines will most likely lead to social resistance. This can already be  observed in Germany, where affected residents increasingly block the construction of new transregional transmission lines, which would be needed to better distribute the increasing amounts of electricity produced from wind and solar power plants. Or take the adoption behaviour of people or organizations, which is rarely purely rational, but instead often driven by norms, habits or routines.

These are only two of the many examples that show that the utilization of renewables strongly depends on broader social systems consisting of various interacting actors and institutions. A successful uptake of renewables will require profound changes of these systems. As these systems have, however, a high inertia and do not change overnight, it is all the more important to better understand their characteristics. Only then strategies can be found to overcome this inertia and to lay the foundations for a successful transition towards renewable energies.


Alexander E. MacDonald; Christopher T. M. Clack; Anneliese Alexander; Adam Dunbar; JamesWilczak; Yuanfu Xie (2016): Future cost-competitive electricity systems and their impact on US CO2 emissions. Nature Climate Change 6, pp. 526–531

Mark Z. Jacobson; Mark A. Delucchi; Guillaume Bazouin; Zack A. F. Bauer; Christa C. Heavey; Emma Fisher; Sean B. Morris; Diniana J. Y. Piekutowski; Taylor A. Vencilla; Tim W. Yeskooa (2015): 100% clean and renewable wind, water, and sunlight (WWS) all-sector energy roadmaps for the 50 United States. Energy & Environmental Science 8, pp. 2093-2117

Picture used under Creative Commons License 2.0, made by Patrick Finnegan, 2007