Land competition and its impact on decarbonized energy systems: A case study for Germany

In densely populated countries, land competition is a key challenge in light of a growing population and the land-intensive decarbonization of energy supply. We apply an energy system model using linear optimization to Germany as an example for a densely populated and industrialized nation with a high energy demand to show how land competition affects the economics of land-intensive renewable energies. Bioenergy crops are currently cultivated on 6.5% of Germany’s land area. We find that allocating only 6% of the total land to the future energy system, which is even less than the current allocation to bioenergy crops, allows for a system that is close to the cost-minimum that we calculate when not restricting the land area. This 6% of the land area is divided into 4% for photovoltaics (PV), 2% for onshore wind and 0% for bioenergy crops. This would save 15 billion €/a (15.1%) relative to the system that matches current political targets for utility-scale PV. For areas exceeding this 6%, we find that the most cost-efficient utilization comes from bioenergy crops, but they only add value to the energy system if there is plenty of land available. The value of land to the energy system is at least twice as high for 0% remaining emissions when compared to the case of 10% remaining green house gas emissions, although both scenarios are separated by less than five years according to current German law. Both our findings underline that considering the value of land as early as possible is necessary when developing state policies that shall lead to cost-efficient renewable energy systems.