scholarly journals A Review on Unit Commitment Algorithms for the Italian Electricity Market

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 18
Author(s):  
Maria Carmen Falvo ◽  
Stefano Panella ◽  
Mauro Caprabianca ◽  
Federico Quaglia
Keyword(s):  
Power Systems ◽  
Electricity Market ◽  
Power Plants ◽  
Unit Commitment ◽  
State Of The Art ◽  
Voltage Regulation ◽  
Ancillary Service ◽  
Service Market ◽  
Renewable Energy Systems ◽  
Input Variables

This paper focuses on the state-of-the-art of unit commitment (UC) and economic dispatch (ED) algorithms suitable for the Italian electricity market. In view of the spread of renewable energy systems (RES), the desired UC algorithm should be able to properly consider the uncertainty affecting key input variables into the formulation of the problem, as well as the different capabilities of dispatched power plants to provide ancillary services (e.g., voltage regulation). The goal of this paper is to resume the developments in UC and ED algorithms which occurred in the last decades, having a particular focus on alternating current (AC) security constrained (SC) approaches and stochastic ones, highlighting the advantages and weakness of each technique. This review is useful for the Italian TSO (Terna) to investigate what is the best solution to formulate a new algorithm to be potentially adopted in the framework of the Italian Ancillary Service Market, striving for an explicit modelization of stochastic variables and voltage constraints. This review is also useful to all system operators (SOs), independently to the market environment in which they operate, because UC algorithms are widely adopted to ensure real-time security of power systems. In conclusion, an SC-UC algorithm which takes into account both stochastic variables and AC formulation does not exist.

Reliability Index of Wind-Solar Hybrid Power Plants using the Expected Energy Not Supplied Method

2019 ◽  
Vol 8 (4) ◽  
pp. 9449-9456
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Electricity Market ◽  
Reliability Index ◽  
Power Plants ◽  
Initial Conditions ◽  
Hybrid Plant ◽  
Total Power ◽  
Hybrid Power ◽  
Hybrid Power Plant

This paper proposes the reliability index of wind-solar hybrid power plants using the expected energy not supplied method. The location of this research is wind-solar hybrid power plants Pantai Baru, Bantul, Special Region of Yogyakarta, Indonesia. The method to determine the reliability of the power plant is the expected energy not supplied (EENS) method. This analysis used hybrid plant operational data in 2018. The results of the analysis have been done on the Pantai Baru hybrid power plant about reliability for electric power systems with EENS. The results of this study can be concluded that based on the load duration curve, loads have a load more than the operating kW of the system that is 99 kW. In contrast, the total power contained in the Pantai Baru hybrid power plant is 90 kW. This fact makes the system forced to release the load. The reliability index of the power system in the initial conditions, it produces an EENS value in 2018, resulting in a total value of 2,512% or 449 kW. The EENS value still does not meet the standards set by the National Electricity Market (NEM), which is <0.002% per year. Based on this data, it can be said that the reliability of the New Coast hybrid power generation system in 2018 is in the unreliable category.

Ancillary Services Potential for Flexible Combined Cycles

2021 ◽  
Author(s):  
Alberto Vannoni ◽  
Jose Angel Garcia ◽  
Weimar Mantilla ◽  
Rafael Guedez ◽  
Alessandro Sorce
Keyword(s):  
Electricity Market ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Ancillary Services ◽  
Ancillary Service ◽  
Spinning Reserve ◽  
Service Market ◽  
Partial Load ◽  
Ancillary Services Market

Abstract Combined Cycle Gas Turbines, CCGTs, are often considered as the bridging technology to a decarbonized energy system thanks to their high exploitation rate of the fuel energetic potential. At present time in most European countries, however, revenues from the electricity market on their own are insufficient to operate existing CCGTs profitably, also discouraging new investments and compromising the future of the technology. In addition to their high efficiency, CCGTs offer ancillary services in support of the operation of the grid such as spinning reserve and frequency control, thus any potential risk of plant decommissioning or reduced investments could translate into a risk for the well-functioning of the network. To ensure the reliability of the electricity system in a transition towards a higher share of renewables, the economic sustainability of CCGTs must be preserved, for which it becomes relevant to monetize properly the ancillary services provided. In this paper, an accurate statistical analysis was performed on the day-ahead, intra-day, ancillary service, and balancing markets for the whole Italian power-oriented CCGT fleet. The profitability of 45 real production units, spread among 6 market zones, was assessed on an hourly basis considering local temperature, specific plant layouts, and off-design performance. The assessment revealed that net income from the ancillary service market doubled, on average, the one from the day-ahead energy market. It was observed that to be competitive in the ancillary services market CCGTs are required to be more flexible in terms of ramp rates, minimum environmental loads, and partial load efficiencies. This paper explores how integrating a Heat Pump and a Thermal Energy Storage within a CCGT could allow improving its competitiveness in the ancillary services market, and thus its profitability, by means of implementing a model of optimal dispatch operating on the ancillary services market.

Advances in Direct Fuel Cell/Gas Turbine Power Plants

2003 ◽  
Author(s):  
Hossein Ghezel-Ayagh ◽  
Joseph M. Daly ◽  
Zhao-Hui Wang
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Gas Turbine ◽  
Power Plants ◽  
State Of The Art ◽  
Combined Cycle ◽  
Proof Of Concept ◽  
Hybrid Power Systems ◽  
Fuel Cell Stack ◽  
T System

This paper summarizes the recent progress in the development of hybrid power systems based on Direct FuelCell/Turbine® (DFC/T®). The DFC/T system is capable of achieving efficiencies well in excess of state-of-the-art gas turbine combined cycle power plants but in much smaller size plants. The advances include the execution of proof-of-concept tests of a fuel cell stack integrated with a microturbine. The DFC/T design concept has also been extended to include the existing gas turbine technologies as well as more advanced ones. This paper presents the results of successful sub-MW proof-of-concept testing, sub-MW field demonstration plans, and parametric analysis of multi-MW DFC/T power plant cycle.

scholarly journals Hydro-reservoir management and unit-commitment in energy optimization

2021 ◽  
Author(s):  
Flávio Leite Loução Junior ◽  
Marlon Sproesser Mathias ◽  
Claudia Sagastizábal ◽  
Luiz-Rafael Santos ◽  
Francisco Nogueira Calmon Sobral
Keyword(s):  
Power Systems ◽  
Demand Response ◽  
Power Plants ◽  
Unit Commitment ◽  
Thermal Power ◽  
Point Of View ◽  
Mixed Integer ◽  
Thermal Power Plants ◽  
Hydro Power ◽  
Optimal Dispatch

In partnership with CCEE, CEPEL and RADIX as industrial partners, in 2021 the study group focused on the dynamics of hourly prices when industrial consumers are demand responsive, as a follow-up of the industrial problem tackled in 2018 and 2019, on ``Day-ahead pricing mechanisms for hydro-thermal power systems''. Demand response is currently being tested by the Brazilian independent system operator and by the trading chamber, ONS. The program considers reductions of consumption of some clients as an alternative to dispatching thermal power plants out of the merit order. The day-ahead problem of finding optimal dispatch and prices for the Brazilian system is modelled as a mixed-integer linear programming problem, with non-convexities related to fixed costs and minimal generation requirements for some thermal power plants. The work focuses on the point of view of an individual hydro-power generator, to determine business opportunities related to adhering to a demand response program.

Short-Term Generation Schedule Optimisation for Combined Heat and Power

2011 ◽  
Author(s):  
E. E. B. Gomes ◽  
P. Pilidis ◽  
A. L. Polyzakis
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Electricity Market ◽  
Power Plants ◽  
Hybrid Genetic Algorithm ◽  
Combined Heat And Power ◽  
End Users ◽  
Technical Literature ◽  
Priority List ◽  
Distributed Generators

In the last decades one of the most difficult problems in the electricity market has been how to dispatch and manage the electricity in power generation plants. Despite of all the benefits of distributed poly-generation and combined heat and power systems, their penetration in the power market worldwide is quite modest and one of the barriers against their increasing participation is the high fees for back-up supplies, which is one of the problems addressed in this investigation. This paper introduces a pool of distributed generation units (named nerve-centre) able to economically optimise the generation schedule of gas turbine power plants and end-users interconnected through a mini-grid. A hybrid genetic algorithm adapted priority list was developed to solve the multi unit generation schedule optimisation problem. The algorithm developed in this study leads the optimisation mechanism to a faster convergence and a very low risk of non-convergence to the optimal result. Despite the power generation optimisation studies reported in the technical literature, none of them has been modelled for such a pool of distributed generators trading electricity in the competitive market. This investigation shows that the proposed nerve-centre concept can result in significant savings to generators/end-users.

scholarly journals On the Way to Integrate Increasing Shares of Variable Renewables in China: Experience from Flexibility Modification and Deep Peak Regulation Ancillary Service Market Based on MILP-UC Programming

2021 ◽  
Vol 13 (5) ◽  
pp. 2446
Author(s):  
Yinhe Bu ◽  
Xingping Zhang
Keyword(s):  
Unit Commitment ◽  
Thermal Power ◽  
Mixed Integer ◽  
Ancillary Service ◽  
Unit Commitment Problem ◽  
Service Market ◽  
Price Rule ◽  
Commitment Problem ◽  
The Government ◽  
Price Differences

China has declared ambitious carbon emission reduction targets and will integrate increasing shares of variable renewables for the next decades. The implementation for flexibility modification of thermal power units and deep peak regulation ancillary service market alleviates the contradiction between rapid capacity growth and limited system flexibility. This paper establishes three flexibility modification schemes and two price rules for simulation and proposes an analysis framework for unit commitment problem based on mixed-integer linear programming to evaluate the policy mix effects. Results confirm the promoting effects of flexibility modification on integrating variable renewables and illustrate diverse scheme selections under different renewables curtailment. Particularly, there is no need for selecting expensive schemes which contain more modified units and more developed flexibility, unless the curtailment decrement is compulsorily stipulated or worth for added modification cost. Similarly, results also prove the revenue loss compensation effect of deep peak regulation ancillary service market and illustrate diverse price rule selections under different curtailment intervals. Price rule with more subdivided load intervals and bigger price differences among them is more effective, especially under the higher requirement for curtailment rate. Therefore, the government should further enlarge flexibility modification via but not limited to more targeted compensation price, while generators should further consider a demand-based investment.

scholarly journals Research on Basic Characteristics and Bidding Strategy of Thermal Power Units in Fujian Spot Market

2021 ◽  
Vol 252 ◽  
pp. 02005
Author(s):  
Yuhui Song ◽  
Zhanhua Pan ◽  
Baike Chen ◽  
Zhaoxia Jing
Keyword(s):  
Electricity Market ◽  
Power Plants ◽  
Thermal Power ◽  
Spot Market ◽  
Bidding Strategy ◽  
Cost Calculation ◽  
Market Environment ◽  
Service Market ◽  
Electric Generator ◽  
Bidding Strategies

In the electricity market environment, thermal power units have changed from the executors of power production under the monopoly mechanism to the decision-makers of production and operation under the competitive environment. The merits and demerits of bidding schemes for thermal power units are directly related to self-interest of themselves. The bidding decisions of power plants are not only affected by economic factors, but also by technical factors peculiar to the power system and the electric generator. In recent years, research on bidding strategies of thermal power units based on the power market environment has been paid more and more attention in the field of electric market. This paper first introduces the basic peak regulation and frequency modulation technical characteristics of thermal power units and cost calculation. Then, from the angle of quotation, paper analyzes characteristics of quotation mechanism of units in Fujian Electric Power day-ahead, real-time and peak regulation auxiliary service market. Furthermore, the research status of bidding strategies of thermal power units participating in electricity market at home and abroad in cost analysis, market clearing price prediction, game theory and so on are summarized. Finally, the bidding strategy for units in Fujian Spot Market is put forward.

scholarly journals State-of-the-art review on frequency response of wind power plants in power systems

2017 ◽  
Vol 6 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Ziping WU ◽  
Wenzhong GAO ◽  
Tianqi GAO ◽  
Weihang YAN ◽  
Huaguang ZHANG ◽  
...  
Keyword(s):  
Power Systems ◽  
Frequency Response ◽  
Wind Power ◽  
Power Plants ◽  
State Of The Art ◽  
Wind Power Plants

scholarly journals Challenges of Storage in Large Power Systems

2021 ◽  
Author(s):  
Gustavo A. Gómez-Ramírez ◽  
Carlos Meza
Keyword(s):  
Solar Energy ◽  
Power Systems ◽  
Power System ◽  
Central America ◽  
Service Providers ◽  
Voltage Regulation ◽  
Frequency Regulation ◽  
Ancillary Service ◽  
Large Power ◽  
Power Sources

Fossil fuel-based electric generation is a contributor to air pollution in the world. In this regard, storage provides a viable specially if it is combined with solar energy and wind generation. Storage also represents a major challenge for the traditional criteria for planning the power system, which its generated with hydro and non-renewable generation as Central America case. This article reviews literature in loadability, frequency regulation and control, stability, economic issues, reliability, harmonics and power quality and resilience applied to power systems. It presents a simulation using ETAP to analyze voltage profiles considering storage for El Salvador Power System (ESPS). The result shows a significant contribution in to enhance the voltage profiles and voltage regulation after failed. Opportunities also arise when storage is considered as potential ancillary service providers that can help to stabilize the grid under faulty situation or to mitigate the power generation variability of non-traditional renewable power sources such as wind and solar energy in Central America Power System. The present paper provides an overview of the major challenges of storage to large power systems.

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