China
Africa
Explore chapters and articles related to this topic
Smart Grid Technologies
Published in Clark W. Gellings, Smart Grid Planning and Implementation, 2020
Transmission system operators (TSOs), which is inclusive of traditional utility transmission owners/operators, independent system operators (ISOs), and regional transmission organizations (RTOs) and others (all referred to as TSOs) are making investments in an increasingly robust communications infrastructure as well as an enhanced analytical and forecasting capability. These investments are being made in response to requirements for TSOs to incorporate increasing functionality in order to maintain reliability, meet load growth, and to comply to new regulations which are increasing grid compliance with Federal Energy Regulatory Commission (FERC) rules, increasing the use of distributed resources, demand response and energy efficiency. At the same time, market operations are becoming increasingly more complex, the threat of cyber security is increasing, and pressures are continuing to mount to maintain costs and improve the use of assets.
Regulation of electricity markets in Europe in light of the Clean Energy Package
Published in Tina Soliman Hunter, Ignacio Herrera Anchustegui, Penelope Crossley, Gloria M. Alvarez, Routledge Handbook of Energy Law, 2020
Ignacio Herrera Anchustegui, Andreas Formosa
Electricity, unlike other forms of energy, cannot be stored easily or cheaply. This means the electricity grid has to remain balanced in real time so that demand for electricity perfectly matches the supply of electricity.51 The role of balancing the grid has largely been carried out by Transmission System Operators (also known as TSOs) or similar organisations. Historically this function of the TSO was a straightforward task as it was relatively easy to predict supply and demand on any given day.52 Generation was largely centralised (and therefore “dispatchable”),53 thermal, nuclear or large hydro, while supply was inelastic. With the exponential rise of variable renewable energy coupled with advances in digital technology that allow consumers to actively participate in energy markets, the role of balancing the grid has changed and become more challenging for traditional TSOs.
Electricity market overview
Published in Jin Zhong, Power System Economic and Market Operations, 2018
In real time, electricity demand fluctuates. The total energy traded through bilateral transactions and spot markets most probably do not perfectly match the electricity load within the hour. Real-time power balancing is needed in electricity markets. Real-time power balancing is provided as an ancillary service. In Europe, the TSO has the responsibility to obtain power in electricity balancing market to maintain real-time power balance. In the United States, the real-time power balancing is maintained by frequency regulation service and reserve service, which are procured by the ISO. Balancing service, frequency regulation, and reserves are categorized as ancillary services in the deregulated power system. They are procured in ancillary service markets. Ancillary service market is a different type of market compared to energy market. The procurement of balancing services and regulation services differs in different markets. Their pricing mechanisms are different as well.
Dynamic Modeling of a Parabolic Trough Solar Thermal Power Plant with Thermal Storage Using Modelica
Published in Heat Transfer Engineering, 2018
Rubén M. Montañés, Johan Windahl, Jens Pålsson, Marcus Thern
The European Union is committed towards a decarbonized energy system by 2050 with a stated goal of reducing greenhouse gas emissions by 85–95% from 1990 levels. This ambitious goal will put intense pressure on energy systems, where electric energy systems will play an increased role in decarbonized scenarios by covering higher proportion of energy demands. Furthermore, greater shares of renewable energy generation are expected to be progressively introduced into the power system [1]. In this context, it is expected that volatile renewable energy technologies such as wind and solar photovoltaics will be extensively connected to the power grid. Thus, the flexibility requirements of power systems will need to change to match the volatile nature of variable generation (VG) [2]. To handle these flexibility needs, the transmission system operators (TSO) can make use of flexible sources such as dispatchable power plants, energy storage systems, demand side management and response, or make use of capacity connections between adjacent areas [3]. Under these conditions, a power plant capable of providing dispatchable renewable energy would be a competitive option. Concentrating solar power (CSP) technology with thermal energy storage is a proven and interesting technology that could provide dispatchable generation, in case of including thermal energy storage. In addition, CSP plants could provide base load generation during part of the year provided that they are designed including a thermal energy storage system with sufficient capacity.
A Hybrid Stochastic/Robust Model for Transmission Expansion Planning under an Ellipsoidal Uncertainty Set
Published in Electric Power Components and Systems, 2022
Khalid A. Alnowibet, Ahmad M. Alshamrani
This paper aims to put forth a new mathematical framework for a hybrid stochastic/robust TEP problem that does not have the drawbacks of employing KKT or DT. In this respect, a bilevel TEP model is formulated where the upper level is to find the least-cost investment solution, and the lower level is the market-clearing using linearized AC power flow. The transmission system operator (TSO) is responsible for the TEP in a deregulated electricity market. To obtain the optimal expansion plan, TSO needs to know the locational marginal prices and accepted volume of bids and offers by generators and consumers using a network-constrained market-clearing model to maximize social welfare. This pool-based market is cleared by a market operator (MO).
Hosting Capacity Assessment in Electrical Power Distribution Systems Using Genetic Algorithm
Published in Electric Power Components and Systems, 2023
Merisa Hanjalić, Emina Melić, Mirza Šarić, Jasna Hivziefendić
This section presents optimization results, followed by their discussion, limitations, and future research direction. For Case 1, the HC is 28.98 MW, which represents 251.32% of the total active power load of the system. This is a relatively high value, which can be explained by the relatively light load of the network. This fact immediately highlights the influence of network characteristics and initial operating parameters. However, the result is consistent with expected maximum values and results found in similar research. It is higher compared to the result presented in Ref. [22] which found HC to be 213.2% of the peak load, but lower to research analyzed in Ref. [9]. Values over 200% are also reported in Ref. [23]. Generally, the test system is oversized and even experienced a slight decrease in load. In practice, the operational conditions of Case 1 come at the expense of not being able to provide voltage control using variable power factor. This limitation becomes more severe with increase in the installed PV power. Light load implies that a portion of generated power will be back fed to transmission systems. In a similar study, the HC of the distribution network was 44.99% of the peak active power demand [24], which is a lower value. The main reason is selection transformer back feed constraint, which was also taken into consideration in Ref. [25]. This is still permitted by current regulations but it is generally unwelcomed due to issues such as a voltage drop, increase in inrush current, problems with deriving a neutral, higher fault current, increased temperature, insulation stresses, and finally void of standard warranty in some cases. Also, protection coordination becomes an issue due to the changes in the line impedance, the increase of short-circuit currents, or the X/R ratio [26]. In practical situation, DSO would allow this HC to be connected, which means that 29.98 MW minus distribution load would be absorbed as a new generation from transmission system operator (TSO) perspective. In recent years, TSO are not only concerned with transformer, protection, and load flow issues, but also with a decrease of inertia caused by penetration of PV sources from the distribution network. This in principle means that it is required to investigate the influence on the transmission network too. Test network operation with maximum HC might be problematic from the energy losses point of view, which tend to increase in the case of high penetration scenarios as shown in previous work [27]. Results presented in this study will be used to promote influence of reverse power flow on power systems.