Energy policy decisions have long-term effects. Large power plants, for instance, require not only a planning period of several years, but a term of about 30 years until they are amortised. The power demand in 2050, on the other hand, will not least depend on whether, by then, we will be using electricity for heating or to fuel electric vehicles. In order to assess such developments, ministries, associations, companies and environmental organisations commission scenarios – often with widely differing results. So which scenarios are particularly conclusive? For such an evaluation, the results must be verifiable. In the position paper “Consulting with energy Scenarios”, a Working Group of the Academies’ Project “Energy Systems of the Future” (ESYS) has set up guidelines for more transparency.
“Most scenarios are based on mathematical models. These have to be scientifically valid, i.e. created with recognised methods”, explains the Working Group’s chairman, Prof. Armin Grunwald from the Karlsruhe Institute of Technology. In order to verify the results, independent experts must be able to recalculate them. Freely available open source models would create the greatest possible transparency. However, many implementing institutions do not disclose the source codes of their models, as they are part of their operating capital. The Academies therefore suggest that the data and algorithms should at least be submitted to a reviewer panel.
There are also other options to improve the current practice: Were public institutions to provide a consistent set of reference data and assumptions, it would be easier to compare different energy scenarios. This data could be collected and administered by departmental research institutes such as the German Federal Environment Agency (Umweltbundesamt).
The conclusions drawn from the model calculations for according energy policy measures should be comprehensibly explained and substantiated. “For only if media and civil society can take part in the discussion on the energy systems of the future, can energy scenarios be a legitimate contribution to democratic decision-making”, asserts Armin Grunwald. In this context, uncertainties and assumptions also play a major role: Key figures such as future raw material or carbon prices are difficult to predict. Since according assumptions can greatly affect the results, they should be explained in detail in the documentation. In addition, studies must not be distorted by the exclusion of certain scenarios or results. If, for instance, only such scenarios are examined that meet certain energy policy objectives, this would have to be made transparent.