Stephan Maier

Optimal renewable energy systems for industries in rural regions

BackgroundEnergy systems for smart regions will require on the one hand a much higher share of renewable energy sources for heat and electricity and on the other hand a high standard integration of industry and utilities supplying households and businesses. As energy options become more diverse, integration of industry into the energy provision for settlements and vice versa become important from an economic and ecological point of view. A particular problem is the supply of bio-energy to large industrial complexes as this requires considerable efforts to manage resource provision as well as constructing smart systems to utilise available resources without posing direct competition to the supply of food and feed.MethodsThis paper will discuss the application of Process Network Synthesis (PNS) using the P-Graph method as a tool to generate optimal energy systems supplying industry with energy based on bio-resources in the context of a rural region and small urban centre. Application of these methods to a real life case study in an industrial city in rural context (Weiz in Austria) will be discussed from the viewpoint of general lessons to be learned from the design of complex energy systems linking different energy provision sources to supply industry and residential areas in a systemic way with energy.ResultsThe synthesis resulted in a basic optimal solution containing the economically most feasible regional energy-technology network. Scenarios show differences in resource use and the creation of revenue. Anaerobic digestion, CHP and wood gasification appear for most of the scenarios.ConclusionsThe case study shows that a support of large consumers with sustainable regional energy systems can already be realised with current market prices. Heat demand outside industry critically influences the economic success of regional technology networks. Feed-in tariffs remain as a key factor for the creation of revenue. As regional parameters like resource availability, prices and locations where technologies could be situated change, the economic success also changes. Price limits and stable technologies can be identified.

Optimal Renewable Energy Systems for Smart Cities

Abstract Energy systems for smart cities will require on the one hand a much higher share of renewable energy sources for heat and electricity and on the other hand a high standard of integration of industry and utilities supplying households and business. New technological options such as passive buildings, bio-methane injection into grids, small scale CHP with heat storage and PV driven heat pumps for heat provision alter common strategies to supply larger settlements. As energy options become more diverse, heat integration of industry into cities becomes important from economic and ecological considerations. Stabilising distribution grids in the face of diverging supply and demand profiles will further complicate planning of smart city projects. In the face of these challenges, innovative planning tools will gain importance. This paper will discuss using the P-Graph method in its application to sustainable technology systems. This method will be used to generate optimal energy systems linking industry to smart cities and to integrate innovative energy technologies into such systems. The Sustainable Process Index will be used to evaluate these systems from the ecological sustainability point of view. This sustainability measure is particularly well suited to differentiate between conventional fossil based and renewable source based energy systems. A real life case study of the application of these methods to the challenge of designing the optimal energy system for a smart city will be discussed in the paper. The case study deals with a green field development in a medium sized city in Austria (Graz). This project includes different energy provision sources (e.g. excess heat from industry, ground water energy), low energy buildings and innovative storage and energy provision technologies.

SPIonWEB – Ecological Process Evaluation with the Sustainable Process Index (SPI)

Abstract Chemical engineers however need quick and reliable cradle-to-grave evaluations, conforming to the ISO norm 14040, already at the design stage in order to assess the ecological performance of their design compared to design alternatives as well as to identify ecological hotspots in order to decrease the ecological impact of the process in question. The Sustainable Process Index methodology has been particularly developed for this purpose and has been widely applied to the measurement of the ecological performance in production systems. Ecological performance is expressed in aggregate form as Ecological Footprint per service unit, thus allowing the engineer to take decisions. De-aggregation into different environmental pressure categories that this methodology allows as well helps the engineer to understand, what causes the engineer to pinpoint the process steps that are critical to the overallperformance of the ecological pressure in a certain process step. For the modelling of these problems the software tool SPIonExcel has been in use in the last decade. SPIonWeb is a web browser based software tool substituting SPIonExcel, which allows to model industrial processes on a thoroughly revised data base and a still more encompassing methodological base. Basic processes like electricity, transport, base chemical production chains are provided in a life cycle based database. Dynamic modelling allows creating process loops which allows simulating changes in the final product ecological performance if sub-process modification are assumed. Besides the Ecological Footprint (calculated with the SPI method) theprogram also features process visualization, detailed material balance for inputs and emissions, CO2 and GWP life cycle emissions. The paper provides examples of ecological process evaluation for different chemical engineering applications, in particular processes providing energy from different renewable sources and bio-chemical processes, e-g. bio-plastic production. Analysing these thoroughly different process chains will be used to highlight the information that can be gleaned from ecological process evaluation during chemical engineering design.

Optimal regional resource utilisation – the St. Margarethen case

Abstract A sufficient, sustainable and economically feasible supply of rural areas with food and energy is a challenging task. Examples for synergetic visions of spatial and energy planning could help to find more integrated energy solutions. An intense analysis of the region as an integral part of an encompassing stakeholder discussion in the region are steps to reveal development potential for renewable resources. A method for an integrated optimisation of resource utilisation is Process Network Synthesis (PNS). In this context coverage of the entire local energy demand was set as one of the boundary conditions. One application for this method is to find the optimum energy technology network for a specific rural area. PNS has been applied to several optimisations of regional energy systems. The PNS method ensures that the optimal use in the given frame is calculated. The aim of the energy optimisation of a project within the energy network ZUERST (Zukunftsorientiertes Energie- und Rohstoffzentrum St. Margarethen / Future Oriented Energy and Resource Centre St. Margarethen) is to develop options for the future development of the energy supply of the town of St. Margarethen (Eastern Styria, Austria). With PNS an optimisation and consistent scenarios for the use of renewable resources that are incurred in the municipal area (extended) were created. A total of thirteen scenarios was calculated. They form the basis of a currently ongoing broad consultation process within the ZUERST region over the further development of the use of locally available renewable resources. The results of the scenarios indicate that the existing biogas plant will remain as an important central energy plant in the scope of the future shape of the energy system of the municipality.