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Abstract The purpose of this study was to examine if the energetic potentials of chicken manure can be used more efficiently in the biogas process by means of pre-treatment with pressure swing conditioning (PSC). Two sub-questions were of interest: the effect of pre-treatment on the nitrogen content in the manure and the effect of pre-treatment on the methane yield. Six variants of PSC were examined concerning nitrogen content and methane yield in batch tests. PSC-variant 150 °C/5 min showed an increase methane yield of 14.4% (to 288 mL/gVS) in best case compared to the untreated reference. The result's kinetic model analysis indicate faster degradation rates. PSC-treatment caused a reduction of the total ammonia nitrogen content of 39% on average of the six variants (via gas phase). One PSC-variant and untreated chicken manure were chosen for continuous fermentation tests in continuous stirred tank reactors in lab-scale. In the continuous test a methane production of 294 mL/g VS for untreated manure was observed and of 297 mL/g VS for PSC-chicken-manure (150 °C/5 min). With the right parameter set, PSC is able to enhance the degradation speed and to decrease the total ammonia nitrogen content of chicken manure with straw pellets as bedding material.

Abstract The purpose of this study was to examine if the energetic potentials of chicken manure can be used more efficiently in the biogas process by means of pre-treatment with pressure swing conditioning (PSC). Two sub-questions were of interest: the effect of pre-treatment on the nitrogen content in the manure and the effect of pre-treatment on the methane yield. Six variants of PSC were examined concerning nitrogen content and methane yield in batch tests. PSC-variant 150 °C/5 min showed an increase methane yield of 14.4% (to 288 mL/gVS) in best case compared to the untreated reference. The result's kinetic model analysis indicate faster degradation rates. PSC-treatment caused a reduction of the total ammonia nitrogen content of 39% on average of the six variants (via gas phase). One PSC-variant and untreated chicken manure were chosen for continuous fermentation tests in continuous stirred tank reactors in lab-scale. In the continuous test a methane production of 294 mL/g VS for untreated manure was observed and of 297 mL/g VS for PSC-chicken-manure (150 °C/5 min). With the right parameter set, PSC is able to enhance the degradation speed and to decrease the total ammonia nitrogen content of chicken manure with straw pellets as bedding material.

Abstract Financing decentralized renewable energy infrastructures in Germany is a complex issue due to the fact that public authorities lack the needed capital and institutional private investors are generally averse to restraints such as high transaction costs and risk-return-concerns. Consequently, alternative financing concepts must be developed to keep the energy transition going. An approach that has recently gained attention in Germany is the concept of financial citizen participation. The concept entails that private individuals contribute to the realization of infrastructure projects by investing in renewable energy projects via various business models and financing concepts. This article illustrates empirical results on the relevance of financial citizen participation within the German renewable energy sector, briefly reviews the technical, political and legal framework that led to the significant development in the field of financial citizen participation and analyzes different business models and citizen participation schemes from Germany with a particular focus on so called energy cooperatives and closed-end funds.

Abstract Financing decentralized renewable energy infrastructures in Germany is a complex issue due to the fact that public authorities lack the needed capital and institutional private investors are generally averse to restraints such as high transaction costs and risk-return-concerns. Consequently, alternative financing concepts must be developed to keep the energy transition going. An approach that has recently gained attention in Germany is the concept of financial citizen participation. The concept entails that private individuals contribute to the realization of infrastructure projects by investing in renewable energy projects via various business models and financing concepts. This article illustrates empirical results on the relevance of financial citizen participation within the German renewable energy sector, briefly reviews the technical, political and legal framework that led to the significant development in the field of financial citizen participation and analyzes different business models and citizen participation schemes from Germany with a particular focus on so called energy cooperatives and closed-end funds.

Abstract Consumers can choose from a wide range of electricity supply contracts, including green power options. Electricity produced from renewable energy involves information asymmetries. With a sample of more than 2,000 German electricity consumers, we tested the proposition of a “lemon market” for renewable energy in a discrete choice experiment. Specifically, we found that, compared to investor-owned firms, additional willingness-to-pay for renewable energy is approximately double when offered by cooperatives or municipally-owned electricity utilities. Consumers who are experienced with switching suppliers have an additional willingness-to-pay of one Eurocent per kilowatt hour for cooperatives and two Eurocents for public enterprises. The results demonstrate that organizational transformation in dynamically-changing electricity markets is not only driven by political initiatives but also by consumers' choices on the market. Public policy may reduce information asymmetries by promoting government labeling of green energy products.

Abstract Consumers can choose from a wide range of electricity supply contracts, including green power options. Electricity produced from renewable energy involves information asymmetries. With a sample of more than 2,000 German electricity consumers, we tested the proposition of a “lemon market” for renewable energy in a discrete choice experiment. Specifically, we found that, compared to investor-owned firms, additional willingness-to-pay for renewable energy is approximately double when offered by cooperatives or municipally-owned electricity utilities. Consumers who are experienced with switching suppliers have an additional willingness-to-pay of one Eurocent per kilowatt hour for cooperatives and two Eurocents for public enterprises. The results demonstrate that organizational transformation in dynamically-changing electricity markets is not only driven by political initiatives but also by consumers' choices on the market. Public policy may reduce information asymmetries by promoting government labeling of green energy products.