Considering the Environmental Impacts of Bioenergy Technologies to Support German Energy Transition

Amarachi Kalu,Ralf Ludwig,Janja Vrzel,Philip Marzahn,Sebastian Kolb,Fabian Pfaffenberger,Juergen Karl

doi:10.3390/en14061534

Abstract

Clean energy for all, as listed in the United Nation’s SDG7, is a key component for sustainable environmental development. Therefore, it is imperative to uncover the environmental implications of alternative energy technologies. SustainableGAS project simulates different process chains for the substitution of natural gas with renewable energies in the German gas market. The project follows an interdisciplinary approach, taking into account techno-social and environmental variabilities. However, this research highlights the project results from the environmental perspective. So far, a detailed assessment of the environmental costs of alternative gas technologies with a focus on the process of energy transition has remained rare. Although such data constitute key inputs for decision-making, this study helps to bridge a substantial knowledge gap. Competing land-use systems are examined to secure central ecosystem services. To fulfill this obligation, an Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) serves as the modelling tool. InVEST assesses ecosystem services (ES) that are or may be affected by alternative bioenergy technologies. Spatially explicit model results include the water provisioning from the Water Yield Model (WYM), soil erosion and sedimentation described by the Sediment Delivery Ratio (SDR), and nutrient fluxes (N) in response to changing land use are obtained through the Nutrient Delivery Ratio (NDR). The detailed model results are finally extrapolated, which provides a comprehensive image of the environmental impacts associated with bioenergy expansion in Germany from our combination of unique Renewable Gas Plants (RGPs). The final result shows that nutrient load will reduce in southern Germany by the year 2050 compared to the reference state, and biomass use reduced by 46% crops.

Highlights

Environmental issues underpinning German’s renewable energy technologies in the phase of energy transition cannot be overemphasized, as there is always an environmental consequence that goes with the way energy is generated and used
Explicit model results include the water provisioning from the Water Yield Model (WYM), soil erosion and sedimentation described by the Sediment Delivery Ratio (SDR), and nutrient fluxes (N) in response to changing land use are obtained through the Nutrient Delivery Ratio (NDR)
This is an indication that the climate is changing, which is important to be considered before choosing energy feedstocks

Summary

Introduction

Environmental issues underpinning German’s renewable energy technologies in the phase of energy transition cannot be overemphasized, as there is always an environmental consequence that goes with the way energy is generated and used. There has been a rise in the global electricity net generation from about 18.8 trillion kWh recorded in 2007 to about 35.2 trillion kWh which is expected in the year 2035 [1]. This growth is fueled by several factors, including population growth, lifestyle, and economic policies, with an expectation to for further growth. Renewable energy is perceived as being totally harmless by many schools of thought, which is not completely true, the forecasted potential impact is on biodiversity and ecosystems, as global energy systems are at risk. Climate change simulations of the Altmuhl watershed in Bavaria show a significant increase in NO3-N loads with an indication that there would be a high and prolonged in-stream nutrient concentration by 2050 [5]

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