# Overnight (greenfield) scenarios¶

The default is to calculate a rebuilding of the energy system to meet demand, a so-called overnight or greenfield approach.

For this, use foresight : 'overnight' in config.yaml, like the example in config.default.yaml.

In this case, the planning_horizons : [2030] scenario parameter can be set to use the year from which cost and other technology assumptions are set (forecasts for 2030 in this case).