Robert J. Goldston
The 2014 Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report included publication on the web of a wide range of scenarios for the future, produced by energy and environment modelers from all over the world. If we select an internationally coordinated set of scenarios that are consistent with a temperature rise of less than 2 degrees Celsius (3.6 degrees Fahrenheit) above the pre-industrial era—the upper-limit goal of the Paris Climate Accords—and average their projections, we find the projection for future electricity production in the table below, shown in units of annually averaged gigawatts electrical <GWe>.
IPCC Projected Worldwide Annually Averaged Electrical Power Production <GWe>
2020 | 2050 | 2100 | |
Solar | 30 | 650 | 3720 |
Nuclear | 400 | 1120 | 2230 |
Wind | 150 | 930 | 2170 |
Biomass | 40 | 540 | 1500 |
Hydro | 410 | 640 | 850 |
Coal + Oil | 920 | 860 | 770 |
Gas | 780 | 980 | 620 |
Geothermal | 30 | 84 | 100 |
Total | 2770 | 5800 | 11900 |
This IPCC-based mean scenario relies heavily on solar and wind, which vary strongly on a daily and seasonal basis. By the time these intermittent energy sources become dominant, later in the century, we may well have developed the capability to mitigate their daily variation using energy storage. Seasonal variation, however, is hundreds of times harder to compensate, and it is difficult to imagine how this can be done effectively. As solar and wind grow in scale they will need to occupy sites with higher variability, and when they become a large fraction of the energy supply, later in the century, the costs associated with their variability will grow.