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8th World Conference on Photovoltaic Energy Conversion; 1320-1324, Accurate short-term solar irradiance forecasts would prove valuable for optimal management and effective operational control of microgrids integrated with the conventional power grid. Because of the intermittent characteristics of renewable energy resources, predicting global solar irradiance is a challenging task. The current forecasting models mainly use historical data, while the unexpected behavior of other environmental indicators, such as cloud movement, is not considered. Therefore, over a short period of time, the present-day forecast results are found to be unreliable, especially for control purposes requiring higher accuracy. To tackle this issue, the article proposes an integrated model based on the hybridization of the numeric weather prediction (NWP) model along with long shortterm memory (LSTM) in the day-ahead (24 hours) horizon. Downward shortwave and longwave solar radiation features are selected from the NWP forecast output to be integrated with the LSTM model. The results show that hybridizing models could significantly improve the forecasting accuracy in overcast and scattered climate conditions by reducing the root mean squared error of the single LSTM model's prediction results from 197.19 and 192.81 to 62.96 and 72.01, respectively.

In this study, comprehensive exergy analysis of a woodchips fired cogeneration system based on organic Rankine cycle (ORC) is presented. The analysis is conducted to an existing cogeneration plant located in Scharnhauser Park, Stuttgart-Ostfildern, Germany that has been in operation since 2003. This study starts with discussing the exergetic analysis methodology, and then defining the most important performance evaluation indicators based on the exergetic analysis (e.g. exergetic efficiency, exergy destruction ratio, relative exergy destruction ratio, and exergy loss ratio).In the first section of the study, the input parameters for a simulation-based analysis is defined. In following sections, a mathematic model of the energy generation process was established. The structure of the model is explained, and the mass and exergy balances of the major system components are discussed in detail. The study shows that the Fixed Bed Combustion Boiler (FBCB) and the ORC evaporator are the main sources of exergy destruction. The FBCB contributes to 58% of the total destructed exergy while the ORC evaporator contributes to 30% of the total destructed exergy. Finally, some recommendations are suggested to optimize the plant’s energy conversion process through reducing the exergy destruction within the FBCB.To achieve higher conversion efficiencies continuous development of the bioenergy systems is needed. The presented study, which is based on experience from a full-scale system, aims to increase the knowledge about the influence of process parameters on the conversion efficiency. The primary and secondary air-flow rates are employed as major controlling parameters to maintain the stability of the combustion and achieve high conversion efficiencies. Simulation results showed that the energy efficiency of the biomass furnace can be increased by more than 2% when an optimized combustion air management system is applied. The study also examines the influence of the fuel moisture on the exergetic efficiency of biomass conversion. Simulation results showed a considerable influence of the fuel moisture on the process efficiency. The evaporation process of the moisture in the combustion chamber absorbs a considerable fraction of the fuel energy, which had an important effect on decreasing the process temperature levels.Finally, clear recommendations were suggested to optimize the plant’s energy conversion process through reducing the exergy destruction within the boiler. The main two factors that seem to improve the exergetic efficiency of the FBCB and consequently of the overall exergetic efficiency of the plant are obtaining woodchips with lower moisture content and decreasing the excess air ratio., Proceedings of the 23rd European Biomass Conference and Exhibition, 1-4 June 2015, Vienna, Austria, pp. 760-768

The potential of fossil fuels is limited and their utilisation for energy purposes has considerable negative effects on the environment. The utilisation of biomass as energy source is a promising alternative for energy generation from renewables, which could significantly contribute to cover the energy demand of the industrial sector. Especially the energy demand of the food industry, which is one of the highest industrial energy user, can be covered by a high extent with biomass.The utilisation of bioenergy as renewable energy source for the industry can significantly reduce CO2 emissions and fossil fuel use, but the role that biomass plays in the covering of the industrial energy consumption in the food processing sector is nowadays rather marginal. There is still a lack of information and studies related to the analysis of possibilities of biomass-based energy utilisation within the food processing industry. One of such initiatives is the Greenfoods project, which aims to lead the European food and beverage industry to high-energy efficiency and reduction of greenhouse gas emissions.In general there is a high variety of biomass conversion technologies, which offer many possibilities to supply food processing companies with secondary and final energy carriers. The work presented in the paper provides an overview of opportunities and barriers related to the utilisation of biomass as an energy source for the food processing industry. In the presented study, six main bioenergy technologies (combustion, gasification, pyrolysis, anaerobic digestion, fermentation and biodiesel production) were analysed with respect to their parameters and applicability as energy sources for the food and beverage industry., Proceedings of the 23rd European Biomass Conference and Exhibition, 1-4 June 2015, Vienna, Austria, pp. 1599-1609

Today, biomass is most efficiently used in decentralized cogeneration plants. Through the use of the ORC (Organic Rankine Cycle) technology, power plants below 10 MWth thermal output can be operated at lower temperature and pressure than conventional steam plants, thus requiring less operation and maintenance effort. Due to high efficiency of part load operation such plants are an interesting alternative for municipal and commercial heat supply. However, the technology is rather new and practical experience is required to access the real performance and operational reliability.The energy supply system of the urban area Scharnhauser Park is a practical example for the utilization of the ORC technology. An urban quarter with a living space of 130000 m2 and 48000 m2 office space is heated by a cogeneration plant connected to a district heating network with a length of 13.5 km. The plant is fired mainly by park waste wood and forest residues are burned additionally. The cogeneration system is equipped with a 6.3 MWth biomass furnace and covers the main part of the heat demands of the quarter. The installation has a pilot project character and can be used for investigations of wood-fired cogeneration systems.The paper contains a review about the practical experience and investigation results that have been gathered since begin of the plant operation. A wood chip boiler with a cogeneration module, connected to a district heating network is being completely monitored from the fuel delivery to heat distribution. More than 60 process parameters have been continuously archived by a data acquisition system. The analysis aims to estimate the efficiency and the ecological parameters of the combination of the ORC module and biomass furnace by consideration of the requirements of a district heating network., Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 1347-1351

The paper describes the development of a new supervisory control system for solar heating and cooling plant

23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 3129-3133, A building integrated photovoltaic façade has been analysed with partial shading through thin objects such as an antenna or through larger neighbouring buildings. The influence of irradiance distribution modeling and accuracy of the PV generator model is discussed in this work.

This paper examines the potential of the greater integration of biomass-fired cogeneration plants based on Organic Rankine Cycle (ORC) technology in modern energy supply concepts, including methods of overcoming typical problems and implications for efficiency enhancement. The biomass infrastructure and energy generation technology needs to be continually adapted and upgraded if it is to meet the ever-increasing demands for energy services. Although decentralized energy supply schemes based on the ORC technology have proven to be efficient, many problems related to fluctuations in heat demand, indirect plant control and varying fuel properties still remain unsolved. Therefore, the aim of this study was to develop a multifunctional system tool, to allow an in-depth analysis of decentralized bioenergy applications and finally to aid in the design and operation of biomass-fired cogeneration plants. The paper describes the optimisation of biomass-based energy supply via innovative and novel components which will allow continuous control of the energy input at the plant. The integration of the energy input within the plant control system has shown to be certainly beneficial for achieving of stable working conditions and enhanced system efficiency of decentralised applications. The presented optimisation approach was not only based on the implementation of new hardware control system components, but it also included a high-effective model predictive control. The main scientific target of the presented methodology was the development of the predictive mathematical models of biomass-based energy conversion plants. New knowledge has been gathered in the fields of process identification, process control algorithms and load management. The main innovative aspect of the study is the development and creation of a simulation environment for the performance analysis of district heating supply systems based on grid simulations. For this, a modular application for the simulation of load profiles was applied, in which 3D geo-data building models and detailed hydraulic grid infrastructure simulation were integrated within an innovative urban energy management platform. This enabled not only the analysis of load management scenarios, but also reliable heat demand forecasts in order to estimate the optimal control parameters for the predicted load characteristics. The main target of the research work was the improvement of the sustainability of biomass-based energy supply concepts. The CO2 emissions savings potential which was mobilised as the result of the project activities is related mainly to the fuel savings linked to the enhancement of the annual system efficiency. In the case of an analysed ORC pilot plant with 1 MW electric output, the fuel demand could be reduced by 6,300 m3 wood chips yearly. The substitution of fossil fuel-based heat and electricity which has been achieved in the course of the optimisation has enabled a summary emissions reduction of 583 tons CO2 yearly., Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 629-633