Engineering assessments of future high wind and solar power penetration tend to focus on central estimates and may understate or ignore the significance of low probability outcomes that may have extremely severe consequences (extending to but no limited to catastrophic risks). This relative neglect of tail risks is partly a result of traditions in prediction and forecasting, and conservatism about phenomena for which very few data and information exist.
The misinterpretation of such engineering assessments can have adverse results. Even though the central estimates of high(1) wind and solar power penetration scenarios present obvious dangers, the tails of lower wind and solar power penetration scenarios still contain very serious risks which may be overlooked by policy-makers. Economic analyses may omit the possibility of catastrophic impacts, leading to substantial under-estimates of damage caused by high wind and solar power penetration.
Blackouts like the one in 2003 will likely be much more frequent when wind and solar penetration exceeds 15 %. We face a disaster of enormous proportions, but lack the means to communicate this awful truth to the public.
So how do we avoid these shortcomings and achieve more effective communication about the risks of high wind and solar power penetration?
The engineering assessments of wind and solar power penetration differ in significant ways from the formal risk assessment methods successfully employed in other fields. We outline a ‘good practice’ approach to the identification, assessment and communication of potentially catastrophic risks based on examples from organizations such the American Geophysical Union, political campaigns, as well as speeches by Rajendra K. Pachauri and Christiana Figueres.
We illustrate how this ‘good practice’ approach could be applied to provide a better presentation of some catastrophic tail risks that are outlined in the Fifth Assessment Report of the Intergovernmental Panel on Wind and Solar Power Use.
The risks we consider include the possibility of ‘extreme’ drops in electricity voltage and supply lying outside the central projections described in the report, and the plausibility of significant economic disasters resulting from brownouts and blackouts taking place on a very frequent basis. The risks can also be illustrated with substation transformer explosions and similar events.
Using these illustrations, we examine how engineering researchers can improve their communication about wind and solar power penetration to assist decision-making, and how policy-makers and politicians might respond differently to alternative presentations of information about the tail risks.
1 Here we define high wind and solar power penetration as having a grid in which these sources deliver over 15 % of the electric power, in a self-contained and isolated grid system with trailing response power storage capacity less than 5 % of the total 10 day load.