Ruth Delzeit

Modelling regional input markets with numerous processing plants: The case of green maize for biogas production in Germany

The location of first generation processing plants for biogas using bulky inputs is a prominent example of locational decisions of plants that face high per unit transport costs of feedstock and simultaneously depend to a large extent on feedstock availability. Modelling the resulting regional feedstock markets then requires a spatially explicit representation of demand. With production capacities of plants small in comparison to market size, large numbers of possible type-location combinations need to be considered, requiring considerable computation time under existing integer programming-based approaches. Therefore, in this paper we aim to present an alternative, faster and more flexible iterative solution approach to simulate location decisions for processing plants. And with greater flexibility, this approach is able to take into account spatially heterogeneous transport costs depending on total demand. The approach is implemented in a modelling framework for biogas production from green maize in Germany, which currently accounts for ca. five per cent of Germanys agricultural area. By modifying green maize prices, demand functions are derived and intersected with regional supply functions from an agricultural model to simulate market clearing prices and quantities. The application illustrates that our approach efficiently simulates markets characterised by small-scale demand units and high, spatially heterogeneous transport costs.

Addressing future trade-offs between biodiversity and cropland expansion to improve food security

Abstract Potential trade-offs between providing sufficient food for a growing human population in the future and sustaining ecosystems and their services are driven by various biophysical and socio-economic parameters at different scales. In this study, we investigate these trade-offs by using a three-step interdisciplinary approach. We examine (1) how the expected global cropland expansion might affect food security in terms of agricultural production and prices, (2) where natural conditions are suitable for cropland expansion under changing climate conditions, and (3) whether this potential conversion to cropland would affect areas of high biodiversity value or conservation importance. Our results show that on the one hand, allowing the expansion of cropland generally results in an improved food security not only in regions where crop production rises, but also in net importing countries such as India and China. On the other hand, the estimated cropland expansion could take place in many highly biodiverse regions, pointing out the need for spatially detailed and context-specific assessments to understand the possible outcomes of different food security strategies. Our multidisciplinary approach is relevant with respect to the Sustainable Development Goals for implementing and enforcing sustainable pathways for increasing agricultural production, and ensuring food security while conserving biodiversity and ecosystem services.

Ökonomische Bewertung des Erneuerbare Energien Gesetzes zur Förderung von Biogas

Abstract The Renewable-Energy-Source-Act (EEG) promotes German biogas production in order to substitute fossil fuels, protect the environment and prevent climate change. In this paper we quantitatively analyse the EEG-reform in 2008. Results imply that the reform contributes to an expansion of biogas electricity generation and thus to substitution of fossil fuels. However, subsidies, land and transport emissions per unit of electricity produced increase. An alternative analysis shows that an EEG with tariffs independent from plant-types would provide the highest subsidy-efficiency, lower land requirements and higher transport emissions compared to EEG before its reformation.