Understanding Decentralized Energy System: Economic, Technical, And Social Impacts

Literature Review for a project topic "System Dynamics modeling of energy systems". It should have to addresses the following subject learning objectives:

1. Select and evaluate information for accuracy, currency and relevancy for the task at hand
2. Synthesise complex ideas, arguments and rationales in research articles to explore alternatives.
3. Identify and justify a research gap and research hypotheses that need addressing.
4. Communicate a comprehensive project proposal within a written document and also course intended learning outcomes

Introduction to Decentralized Energy System

The decentralized energy system is playing a significant role towards shaping the industry of energy supply.  There is significant effort has resulted in a structural change as well as creating shifts in energy supply policy that overall creates effects which cannot just be ignored.  A good instance is in the regenerative energy sources, whereby we have a combination of the heat and power plant as well as the international trading of energy. Hence, the impacts both socially and technologically will forever remain to cater a greater challenge.

Some of the key areas of the decentralized system which have been investigated includes

• The energy potential of the power units with regards to control of the schedule deviation
• The net systems services potential of the decentralized power units for the stabilization of frequency and voltage
• The scheduling of resources in a practical power plant
• The impacts on the environmental aspects including the emission of greenhouse and air pollutants (Dorfler and Bullo, 2012)

The impacts on the economic aspects such as the costs which are incurred while delivering the power to the embedded distributed system from the decentralized energy system. The analysis of the various system is done with the help of special software tools. There are various modeling studies which have in the past proved to be advantageous when it comes to the energy supply field (Gan et al, 2010).

Energy systems

 Energy systems can be defined as a connection of various networks of energy and energy stores which are linked for purposes of transmission and distribution. One example of such as system is the connection of storage of energy and the current dissipation via means of utilization.  Energy systems can either be natural or manmade. For instance, the food chain is an example of a natural energy system. The use of energy has in the present exponentially developed since the early years of civilization (Hiskens and Pai, 2000).

History of an energy system

Pre-industrialization.

Prior to the age of industrialization, the human beings used muscle power in applying energy, while the food chain represented the energy system. The energy systems help in ensuring that various tasks are spread across. The energy needs were largely supplied by biomass and the muscle power which was later replaced by the animal power. The energy sources which were being harnessed at that time included water, wind and the animal power.

Industrial revolution

During the industrial revolution, there was the need for more energy which could be used to meet the energy demands of the various material that were being used during the revolution. There were various studies, for instance about the solar system and the steam engine and their potential. Till the years to 1800, the energy was not well developed. Later on, with the increased demand for the use, there was a proper energy system which was developed for the purposes of ensuring that the ecological, as well as the technological aspects, are achieved (Hollmann, 2016)

The Economic, Technical, and Social Impacts of Decentralized Energy System

Energy use and sources

The table below shows the various use of energy in different countries. Most of the industrialized nations utilize a high amount of energy

Structures involved in decentralized energy supply

A better explanation of the decentralized energy system is by the provision of energy small plants close to the consumers. In most cases, the energy demand is not well tackled by the bigger plants such as the nuclear plant and the coal-fired power system.  The location of the converters in this system is strategic such that they are positioned at the point that the energy is needed. This enables a number of power plants to be available for the consumers.  Besides, the changing of the structure of the power plant is also enabled and some modifications in the energy management, grid operation, and protection system can be easily done.  Hence, the decentralized energy system and the centralized energy system are not mutually exclusive at all. Though, the two energy systems can mutually coexist (Karnopp et al, 2012).

There are a variety of plant technologies which are available for the provision of both the thermal and electrical energy.   The energy from the primary source gets converted to the form which is desired in a series of numerous steps.  The systems which utilize the regenerative technologies as their chief sources of energy i.e. energy conversion plants and the combined heat and power plants have a number of development opportunities more so or the decentralized power supply structure.  The combined heat and power plants which majorly operate by the use of the combustion engines, micro gas turbines, fuel cells and the stirring engine.   The regenerative sources can either be exploited technically or directly and they include solar radiation, geothermal energy, wind energy and the water power.   

There is usually some fluctuations in the electrical output more so or the wind and solar energy since they majorly depend on the weather conditions.  The diagram below represents an illustration of the decentralized energy supply system (Kundur et al, 2014). 

 The economic, as well as the technical bundling of various decentralized power stations and loads, is known as a virtual power plant. Hence, a well-trained expertise in the field of communication infrastructure is required for the connection purposes of the decentralized energy supply (Lopes, 2016). 

Modeling concept

Developed by jay w. Forrester in Cambridge, MIT university,, the system dynamics mutually connects various procedures, theories, and philosophies that are essential when it comes to the analysis of the behaviors of complex feedback systems that are experienced in specific fields of environmental science, economics, technology, medicine and cooperate management.  This techniques has its basis on the cybernetic knowledge and applies the systematic thinking and numeric simulation methodologies in order to come up with the behavior of nonlinear systems.   The energy supply engineering poses various aspects just like any other technical profession including ecology, politics, economics, and sociology.  Hence, the possibility of linking up these various systems comes with a lot of diversifications and coming up with various solutions to a lot of challenges.  The system dynamics have some properties which make them more advantageous. For instance (Momoh, 2008.)

• They have the stock and flow diagrams which offer intuitive system modules
• The process which takes place is directly discernible
• The various relationships and dependencies are simple and easy to understand
• It has feedback loops which can be easily understood and analyzed. 
• The influencing factors can be easily mapped through the use of separate dynamic process
• Any process can be scaled and individually considered. 
• The integration of the system and the quality process is possible
• The process groups can be easily coordinated and analyzed within the context
• There is the possibility of mutually combining models from other disciplines
• The integration of another influencing process can be done without any challenge
• Relationships can be considered and analyzed, either separately or combined.

Modeling of Decentralized Energy System

Some of the possibilities with system dynamics include (Sauer and Pai, 2008)

• Models management process can be easily executed once there are the assistance o the system dynamics models. 
• The decisions procedures in operation business and strategic management
• Value increasing strategies and the simulation of alternative scenarios such as the power reserve, resource scheduling, net system services and the emission of greenhouse gases.

The primary objective of the various models depends on the ecological and technical potentials. 

Model of the decentralized power supply unit

In this section, modeling of a cogeneration plant which contains a heat accumulator, peak load boiler, and the simulation feedback is presented.  This model comprises various systems in different model sectors such as the 

• Resource scheduling logic (Van, 2010)
• Output system of the result considerations
• Consumer system
• Technical system of the supply unit. 

The logic and the technical system of the supply systems form part of the sore system of the system dynamics. The figure below illustrates the unit, together with the input and the output parameters. 

For the technical modeling shown in the diagram below, the power supply unit has been fully illustrated.   The coo generational plant, peak load boiler, heat accumulator can be easily identified.  The basis of the stock and the flow diagram is enabled by the thermal and electrical power flow.  This forms the fundamental structure of the whole model.

Additionally, a logic resources scheduling has been provided. The three factors of heat accumulator, cogeneration plant, and the peak load boiler have been addressed and the various regulations within the system done.  Hence, the logic scheduling helps in attaining the various feedback process within the system. For instance, in the diagram labeled figure five, there is the presence of a counteracting loop which illustrates the dependencies of the storage level of the heat accumulator. There are as well other feedbacks.   

The diagram below shows the simulation desk for the decentralized power supply unit model together with a display of the numerical model. For instance power reserve, utilization ratio, and the resource scheduling.

Proposed system model

In the above explanation, the decentralized power supply unit represents a model of specific energy converter which is utilized as a superordinate model. For the new system, it has the possibility of incorporating various aspects such as the solar thermal heating, energy converters, geothermal heating among others by means of comprehensive simulation.  The assumption in the model is that the grid supply is linked to the transmission grid and there are zero restrictions in the system hence the system is fully stable. The consumers take place within standards electrical heat and load profiles and various aspects adjusted accordingly. The input structure o this system model is described below (Wang and Nehrir, 2008)

For the simulation model concept, the technical process and the basis of the simulation flow are shown below together with the simulation done by the aid of the system dynamics. The diagram below shows the logical representation of the simulation results.    

Conclusion

In this research paper, the system dynamics approach has been demonstrated in the energy supply sector. The various advantages which are linked to the system dynamics have also been presented.  A new model of the energy system with regards to the decentralized system has been elaborated band its potential to the supply industry. In the primary objective of the models is the lies with the ecological potential and the technical potential of the decentralized energy supply system (Wang and Nehrir, 2008)

References

Ackermann, T. ed., 2015. Wind power in power systems. John Wiley & Sons.

Anaya-Lara, O. and Acha, E., 2012. Modeling and analysis of custom power systems by PSCAD/EMTDC. IEEE transactions on power delivery, 17(1), pp.266-272.

Deshmukh, M.K., and Deshmukh, S.S., 2008. Modeling of hybrid renewable energy systems. Renewable and Sustainable Energy Reviews, 12(1), pp.235-249.

Dorfler, F. and Bullo, F., 2012. Synchronization and transient stability in power networks and nonuniform Kuramoto oscillators. SIAM Journal on Control and Optimization, 50(3), pp.1616-1642.

Gan, D., Thomas, R.J. and Zimmerman, R.D., 2010. Stability-constrained optimal power flow. IEEE Transactions on Power Systems, 15(2), pp.535-540.

Hiskens, I.A., and Pai, M.A., 2010. Trajectory sensitivity analysis of hybrid systems. IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications, 47(2), pp.204-220.

Hollmann, M., 2016. System dynamics modeling and simulation of distributed generation for the analysis of a future energy supply. In The 24th International Conference of the System Dynamics Society, Nijmegen, The Netherlands.

Karnopp, D.C., Margolis, D.L. and Rosenberg, R.C., 2012. System dynamics: modeling, simulation, and control of mechatronic systems. John Wiley & Sons.

Kundur, P., Balu, N.J. and Lauby, M.G., 2014. Power system stability and control (Vol. 7). New York: McGraw-hill.

Lopes, J.P., Moreira, C.L. and Madureira, A.G., 2016. Defining control strategies for microgrids islanded operation. IEEE Transactions on power systems, 21(2), pp.916-924.

Momoh, J.A., 2008. Electric power system applications of optimization. CRC press.

Sauer, P.W., and Pai, M.A., 2008. Power system dynamics and stability. Urbana.

Van Cutsem, T., 2010. Voltage instability: phenomena, countermeasures, and analysis methods. Proceedings of the IEEE, 88(2), pp.208-227.

Wang, C. and Nehrir, M.H., 2008. Power management of a stand-alone wind/photovoltaic/fuel cell energy system. IEEE transactions on energy conversion, 23(3), pp.957-967.