Renewable energy supplied approximately 17 percent of global final energy consumption in 2010 and roughly eight percent of this total came from modern renewable energy sources, including hydropower, wind, solar, geothermal, biofuels, and modern biomass. In the power sector renewables supplied approximately 20 percent of global electricity, including 15 percent from hydropower. Countries such as Brazil and Iceland have demonstrated that it is possible to run power systems predominantly by renewable energy. Germany has demonstrated the feasibility of making an energy system transition to renewables by increasing its share of renewable power production to nearly 20 percent in two decades.

The share of renewable energy in global final energy consumption is increasing rapidly. Already more than half of annual capacity additions in the power sector are accounted for by renewables, resulting in a doubling of the share a decade ago. In 2011, 41 gigawatts (GW) of wind, 30 GW of hydropower, 28 GW of solar PV and approximately 5 GW of other renewable power generation capacity was added, out of less than 200 GW in total annual power generation capacity additions. These facts suggest that renewables are gaining traction as a primary source of power generation—but, as with prior energy transitions, the timescale for a shift in the energy mix is measured in decades.

Executive Summary

The industrial sector accounts for about 30% of the global final energy use and accounts for about 115 EJ of final energy use in 2005. Cement, iron and steel, chemicals, pulp and paper and aluminum are key energy intensive materials that account for more than half the global industrial use.

There is a shift in the primary materials production with developing countries accounting for the majority of the production capacity. China and India have high growth rates in the production of energy intensive materials like cement, fertilizers and steel (12–20%/yr). In different economies materials demand is seen to grow initially with income and then stabilize. For instance in industrialized countries consumption of steel seems to saturate at about 500 kg/ capita and 400–500 kg/capita for cement.

The aggregate energy intensities in the industrial sectors in different countries have shown steady declines – due to an improvement in energy efficiency and a change in the structure of the industrial output. As an example for the EU-27 the final energy use by industry has remained almost constant (13.4 EJ) at 1990 levels. Structural changes in the economies explain 30% of the reduction in energy intensity with the remaining due to energy efficiency improvements.

In different industrial sectors adopting the best achievable technology can result in a saving of 10–30% below the current average. An analysis of cost cutting measures for motors and steam systems in 2005 indicates energy savings potentials of 2.2 EJ for motors and 3.3 EJ for steam.

Executive Summary

Chapter 17 explores possible transformational pathways of the future global energy system with the overarching aim of assessing the technological feasibility as well as the economic implications of meeting a range of sustainability objectives simultaneously. As such, it aims at the integration across objectives, and thus goes beyond earlier assessments of the future energy system that have mostly focused on either specific topics or single objectives. Specifically, the chapter assesses technical measures, policies, and related costs and benefits for meeting the objectives that were identified in Chapters 2 to 6, including:

• providing almost universal access to affordable clean cooking and electricity for the poor;

• limiting air pollution and health damages from energy use;

• improving energy security throughout the world; and

• limiting climate change.

The assessment of future energy pathways in this chapter shows that it is technically possible to achieve improved energy access, air quality, and energy security simultaneously while avoiding dangerous climate change. In fact, a number of alternative combinations of resources, technologies, and policies are found capable of attaining these objectives. From a large ensemble of possible transformations, three distinct groups of pathways (GEA-Supply, GEA-Mix, and GEA-Efficiency) have been identified and analyzed. Within each group, one pathway has been selected as “illustrative” in order to represent alternative evolutions of the energy system toward sustainable development. The pathway groups, together with the illustrative cases, depict salient branching points for policy implementation and highlight different degrees of freedom and different routes to the sustainability objectives.