Optimization of CHCP Operation Strategy: Cost vs Primary Energy Consumption Minimization

2013 ◽  
Author(s):  
Andrea Luigi Facci ◽  
Luca Andreassi ◽  
Fabrizio Martini ◽  
Stefano Ubertini
Keyword(s):  
Energy Consumption ◽  
Electricity Market ◽  
Power Plants ◽  
Combustion Engine ◽  
Energy System ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Energy Prices ◽  
Auxiliary Equipment ◽  
Fuel Price

An effective methodology to determine the optimal operational strategy for a complex CHCP plant is presented. The model is based on the minimization of a chosen variable and it is organically developed integrating thermodynamics and economics. The graph-based optimization algorithm is developed in order to find the optimal set-points of the energy system components in a sufficiently short-time. By this way the model is applicable to real industrial problems, especially when the energy is sold to the electricity market. The problem in study is discretized in time and plant states, represented as weighted graph, and the strategy that minimizes the total cost is determined using backward dynamic programming. The proposed methodology has been applied to the optimization of the set-point of an internal combustion engine based plant used to satisfy an hospital energy load, under different seasonal load conditions (winter, summer and transitional seasons) and energy prices. Two different optimization criteria are considered, namely economical optimization and primary energy consumption minimization. It is then demonstrated that the model can be effectively applied to analyze the cost and profit in energy conversion in power plants, related to electricity price, fuel price, running of turbine and auxiliary equipment, service power consumption. In particular, the chosen test case demonstrates not only the model reliability but also the economical and thermodynamic convenience of using the model itself to optimize the plant.

Comparing Energy and Cost Optimization in Distributed Energy Systems Management

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Andrea Luigi Facci ◽  
Luca Andreassi ◽  
Fabrizio Martini ◽  
Stefano Ubertini
Keyword(s):  
Time Series ◽  
Energy Consumption ◽  
Internal Combustion Engine ◽  
Objective Function ◽  
Distributed Generation ◽  
Control Strategy ◽  
Combustion Engine ◽  
Energy Systems ◽  
Primary Energy ◽  
Primary Energy Consumption

Distributed generation, despite not being a new concept, is assuming a leading role in the field of energy conversion, as it should contribute to the enhancement of efficiency, flexibility, and reliability of national energy systems. However, it also noted that the effective performances of small and flexible power plants is critically influenced by their actual control strategy. Moreover, it is not trivial to identify a univocal parameter to evaluate the plant performance. For instance, cost evaluation clearly responds to an industrial view of the energy supply problem, while energy consumption or polluting emissions comply with a socio economic approach. In this scenario, the optimization of the plant management is a valuable instrument to gain insight on their behavior as the control strategy is varied, as well as to promote the distributed generation development, by maximizing the plants performances. In this paper, we further develop a graph based optimization methodology to optimize the set-point of an internal combustion engine based plant used to satisfy a hospital energy load, under different seasonal load conditions (winter, summer, and transitional seasons) and energy prices. Specifically, in order to dissect the effects of the objective function selection, two different optimization criteria are considered, namely economical optimization and primary energy consumption minimization. In particular, we focus on the features of the prime mover (i.e., the internal combustion engine) control strategy and on its drivers, as a function of the prescribed objective function. Results demonstrate that in the actual Italian energy market, cost minimization does not match primary energy consumption minimization, because the latter is only influenced by energy demand time series, and equipments performance, while the former is fundamentally driven by the electricity prices time series.

scholarly journals Optimal Management of the Energy Flows of Interconnected Residential Users

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1507 ◽  
Author(s):  
Lucrezia Manservigi ◽  
Mattia Cattozzo ◽  
Pier Ruggero Spina ◽  
Mauro Venturini ◽  
Hilal Bahlawan
Keyword(s):  
Energy Consumption ◽  
Energy Storage ◽  
Energy Systems ◽  
Electrical Energy ◽  
Energy System ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Prime Mover ◽  
Operation Strategy ◽  
Electrical Energy Storage

In recent years, residential users have begun to be equipped with micro-CHP (combined heat and power) generation technologies with the aim of decreasing primary energy consumption and reducing environmental impact. In these systems, the prime mover supplies both thermal and electrical energy, and an auxiliary boiler and the national electrical grid are employed as supplementary systems. In this paper, a simulation model, which accounts for component efficiency and energy balance, was developed to replicate the interaction between the users and the energy systems in order to minimize primary energy consumption. The simulation model identified the optimal operation strategy of two residential users by investigating different energy system configurations by means of a dynamic programming algorithm. The reference scenario was compared to three different scenarios by considering independent energy systems, shared thermal and electrical energy storage and also the shared prime mover. Such a comparison allowed the identification of the most suitable energy system configuration and optimized operation strategy. The results demonstrate that the optimized operation strategy smoothes the influence of the size of thermal and electrical energy storage. Moreover, the saving of primary energy consumption can be as high as 5.1%. The analysis of the economic feasibility reveals that the investment cost of the prime mover can be as high as 4000 €/kW.

scholarly journals Cost-Benefit Analysis of Hybrid Photovoltaic/Thermal Collectors in a Nearly Zero-Energy Building

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1582 ◽  
Author(s):  
Conti ◽  
Schito ◽  
Testi
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Electrical Energy ◽  
Energy System ◽  
Primary Energy ◽  
Hot Water ◽  
Solar Thermal ◽  
Primary Energy Consumption ◽  
Solar Thermal Energy ◽  
Zero Energy

This paper analyzes the use of hybrid photovoltaic/thermal (PVT) collectors in nearly zero-energy buildings (NZEBs). We present a design methodology based on the dynamic simulation of the whole energy system, which includes the building energy demand, a reversible heat pump as generator, the thermal storage, the power exchange with the grid, and both thermal and electrical energy production by solar collectors. An exhaustive search of the best equipment sizing and design is performed to minimize both the total costs and the non-renewable primary energy consumption over the system lifetime. The results show that photovoltaic/thermal technology reduces the non-renewable primary energy consumption below the nearly zero-energy threshold value, assumed as 15 kWh/(m2·yr), also reducing the total costs with respect to a non-solar solution (up to 8%). As expected, several possible optimal designs exist, with an opposite trend between energy savings and total costs. In all these optimal configurations, we figure out that photovoltaic/thermal technology favors the production of electrical energy with respect to the thermal one, which mainly occurs during the summer to meet the domestic hot water requirements and lower the temperature of the collectors. Finally, we show that, for a given solar area, photovoltaic/thermal technology leads to a higher reduction of the non-renewable primary energy and to a higher production of solar thermal energy with respect to a traditional separate production employing photovoltaic (PV) modules and solar thermal (ST) collectors.

The Hydrogen Programs in China

2003 ◽  
Vol 801 ◽  
Author(s):  
Qidong Wang ◽  
Changpin Chen Yongquan Lei ◽  
Lixing Chen ◽  
Xinghua Wang
Keyword(s):  
Hydrogen Production ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Energy System ◽  
Primary Energy ◽  
Hydrogen Economy ◽  
Stages Of Development ◽  
Economy System

ABSTRACTAccording to the stages of development, the hydrogen program in China can be divided into four periods since 1978. The chief activities and accomplishments in each period on hydrogen production, hydrogen processing and use of hydrogen in the form of energy are introduced. The work of consciously transforming the present energy system based upon coal-firing power plants and petroleum powered internal combustion engine vehicles into a hydrogen economy system with primary energy mainly based on renewable energies and recycling of biomass and the use of both electricity and hydrogen as energy vectors is just on its start.

scholarly journals Hydrogen energy system for renewable energy consumption

2021 ◽  
Vol 233 ◽  
pp. 01083
Author(s):  
SONG Jie ◽  
ZHU Yuting ◽  
LIANG Danxi ◽  
CHENG Qing ◽  
YAO Dawei ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Energy Consumption ◽  
Power Systems ◽  
Energy System ◽  
Electric Power Systems ◽  
Primary Energy ◽  
Hydrogen Energy ◽  
Primary Energy Consumption ◽  
Renewable Energy Consumption ◽  
Key Technologies

As a kind of high-quality secondary energy, hydrogen has great potential of application in energy storage and utilization and contributes to consumption of renewable energy in electric power systems. To further increase the proportion of renewable energy in primary energy consumption, this article introduces a hydrogen energy system for renewable energy consumption. In this article, significance and necessity of developing hydrogen energy system are elaborated, the overall structure of hydrogen energy system is presented, key technologies involved with hydrogen system are listed, economical efficiency of hydrogen energy system is analyzed, and development of hydrogen energy system in the future is forecasted.

scholarly journals An Energy Input-Output Table of Pakistan for 1979-80 and Some Applications

1987 ◽  
Vol 26 (4) ◽  
pp. 593-608
Author(s):  
Peter Pintz ◽  
Ivo C. Havinga
Keyword(s):  
Energy Consumption ◽  
Sharp Increase ◽  
Energy Input ◽  
Public Investment ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Energy Prices ◽  
Industrialized Countries ◽  
Input Output ◽  
Exploration And Production

In order to enhance the indigenous supply of energy, Pakistan has launched various investment programmes as a consequence of which 28 percent and 43.2 per• cent of total public investment has been invested in the energy sector, respectively, in the Fifth and the Sixth Five Year Plans. However, despite the sharp increase in investment for indigenous exploration and production, the domestic supply of energy has registered an insignificant increase. Despite substantial increases in energy prices, the growth of the commercial primary energy consumption has increased from 6.8 percent per annum in 1973•74 1979•80 to 7.8 percent per annum in 1979•80 - 1984-85. In fact, Pakistan's energy policies have not succeeded in delinking the growth rate of GPP from primary energy consumption, which has partly been achieved in industrialized countries and in many developing countries. For the period of 1973•74 to 1979•80, the primary energy/ GDP elasticity was 1.20, whereas, it has increased to 1.24 for 1979•80 to 1984-85.

Saving Primary Energy Consumption Through Exergy Analysis of Combine Distillation and Power Plant

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt
Keyword(s):  
Energy Consumption ◽  
Power Plant ◽  
Heat Pump ◽  
Heat Recovery ◽  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Saturated Steam ◽  
Distillation Unit ◽  
Primary Energy Consumption

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.

scholarly journals Electricity Markets during the Liberalization: The Case of a European Union Country

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4317
Author(s):  
Štefan Bojnec ◽  
Alan Križaj
Keyword(s):  
Electricity Markets ◽  
Electricity Market ◽  
Renewable Energy Sources ◽  
Primary Energy ◽  
Lessons Learned ◽  
Policy Implications ◽  
Daily Maximum ◽  
Energy Prices ◽  
Electricity Prices ◽  
Electricity Power

This paper analyzes electricity markets in Slovenia during the specific period of market deregulation and price liberalization. The drivers of electricity prices and electricity consumption are investigated. The Slovenian electricity markets are analyzed in relation with the European Energy Exchange (EEX) market. Associations between electricity prices on the one hand, and primary energy prices, variation in air temperature, daily maximum electricity power, and cross-border grid prices on the other hand, are analyzed separately for industrial and household consumers. Monthly data are used in a regression analysis during the period of Slovenia’s electricity market deregulation and price liberalization. Empirical results show that electricity prices achieved in the EEX market were significantly associated with primary energy prices. In Slovenia, the prices for daily maximum electricity power were significantly associated with electricity prices achieved on the EEX market. The increases in electricity prices for households, however, cannot be explained with developments in electricity prices on the EEX market. As the period analyzed is the stage of market deregulation and price liberalization, this can have important policy implications for the countries that still have regulated and monopolized electricity markets. Opening the electricity markets is expected to increase competition and reduce pressures for electricity price increases. However, the experiences and lessons learned among the countries following market deregulation and price liberalization are mixed. For industry, electricity prices affect cost competitiveness, while for households, electricity prices, through expenses, affect their welfare. A competitive and efficient electricity market should balance between suppliers’ and consumers’ market interests. With greening the energy markets and the development of the CO2 emission trading market, it is also important to encourage use of renewable energy sources.

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