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This paper aims to survey the need for full capacity utilisation of transmission lines in power systems network operations. It proposes a review of the N-1 security criterion that does not ensure reliable dispatch of optimum power flow during outage contingency. The survey aims to enlarge the network capacity utilisation to rely on the entire transmission lines network operation.

The paper suggests transmission line switching (TLS) approach as a viable corrective mechanism for power dispatch. The TLS process is incorporated into a constraint programming language extension optimisation solver that selects the switchable line candidates as integer variables in the mixed integer programming problem.

The paper provides a practical awareness of reserve capacity in the lines that provide network security in outage contingency. At optimum power flow dispatch, the TLS is extended to optimal transmission line switching (OTLS) that indicates optimal capacity utilisation (OCU) of the available reserve capacity (ARC) in the network lines.

Computational efficiency influenced the extension of the OTLS to optimal transmission switching of power flow (OTSPF). The application of OTSPF helps reduce the use of flexible AC transmission systems (FACTS) and construction of new transmission lines..

The paper surveys TLS efforts in network capacity utilisation. The suggested ARC fulfils the need for an index with which the dispatchable lines may be identified for the optimal capacity utilisation of transmission lines network.

This paper aims at assessing the actual use of interregional transmission lines and the opportunity cost of unused capacity. The 13 electric power lines connecting the province of Quebec (Canada) to its neighbours (New Brunswick, New England, New York, Ontario) are analysed for the years 2006, 2007 and 2008.

Hourly electricity transmission data from the Quebec Open Access Same‐Time Information System (OASIS) are analysed and matched with hourly market prices in New Brunswick, New England, New York and Ontario, for the years 2006, 2007 and 2008.

Capacity factors of about 50 per cent are found for these lines. Although increasing from 2006 to 2008, this finding shows that interregional lines are far from being heavily congested. Furthermore, about 25 TWh of additional profitable exports could have taken place every year, given the market conditions and the availability of transmission lines. These exports represented an opportunity cost of about $1 billion per year.

Other network constraints and transaction costs could explain why these profitable transactions have not taken place. However, the lack of available energy most likely explains why exports were limited. The opportunity cost could also be overestimated by not taking into account the price impact of additional exports.

Price regulation in Quebec (with priority given to local loads) should be reviewed to maximize economic efficiency and environmental benefits in the Northeast region.

This is the first analysis of the use of interregional electricity transmission lines. It provides a preliminary estimate of the economic cost of not further integrating different neighbouring regions.

The purpose of this paper is to examine how active consumers, i.e. consumers that can inter-temporally shift their load, can influence electricity prices. As demonstrated in this paper, inter-temporal load shifting can induce negative electricity prices, a recurring phenomenon on power exchanges.

The paper presents a novel electricity-market model assuming a nodal-pricing, energy-only spot market with active consumers. This study formulates an economic equilibrium problem as a linear program and uses an established six-node case study to compare equilibrium prices of a model with inflexible demand to a model with flexible demand of active consumers.

This study illustrates that temporal coupling of hourly market clearing through load shifting of active consumers can cause negative electricity prices that are not observed in a model with ceteris paribus inflexible demand. In such situations, where compared to the case of inflexible demand more flexibility is available in the system, negative electricity prices signal lower total system costs. These negative prices result from the use of demand flexibility, which, however, cannot be fully exploited due to limited transmission capacities, respectively, loop-flow restrictions.

Literature indicates that negative electricity prices result from lacking flexibility. The results illustrate that active consumers and their additional flexibility can lead to negative electricity prices in temporally coupled markets, which in general contributes to increased system efficiency as well as increased use of renewable energy sources. These findings extend existing research in both the area of energy flexibility and causes for negative electricity prices. Therefore, policymakers should be aware of such (temporal coupling) effects and, e.g. continue to allow negative electricity prices in the future that can serve as investment signals for active consumers.

The physical nature of electricity generation and delivery creates special problems for the design of efficient markets, notably the need to manage delivery in real time and the volatile congestion and associated costs that result. Proposals for the operation of the deregulated electricity industry tend towards one of two paradigms: centralized and decentralized. Transmission congestion management can be implemented in the more centralized point‐to‐point approach, as in New York state, where derivative transmission congestion contracts (TCCs) are traded, or in the more decentralized flowgate‐based approach. While it is widely accepted that theoretically TCCs have attractive properties as hedging instruments against congestion cost uncertainty, whether efficient markets for them can be established in practice has been questioned. Based on an empirical analysis of publicly available data from years 2000 and 2001, it appears that New York TCCs provided market participants with a potentially effective hedge against volatile congestion rents. However, the prices paid for TCCs systematically diverged from the resulting congestion rents for distant locations and at high prices. The price paid for the hedge not being in line with the congestion rents, i.e., unreasonably high risk premiums are being paid, suggests an inefficient market. The low liquidity of TCC markets and the deviation of TCC feasibility requirements from actual energy flows are possible explanations.

The purpose of this paper is to analyze the role of industrial self-supply in the transition process from centralized energy generation based on fossil fuels and nuclear power to decentralized supply based on renewable energies in the Bavarian electricity system.

To quantify effects on system and price stability, a model of the Bavarian electricity grid is created and used to simulate electricity system behavior during a 1-year period for scenarios that are characterized by parameter variations in industrial self-supply, nuclear power capacity, renewable power generation and the capacity of electricity imports.

The simulations show that industrial self-supply can reduce instances of maximum grid utilization by 23 per cent and, based on the merit-order effect, decrease electricity market prices by 1.90 and 5.03 €/MWh in the scenarios with and without nuclear power, respectively; these values represent 5.7 and 15.0 per cent of average market prices from 2014.

The analysis shows that industrial self-supply can contribute to transforming the electricity system in a secure, sustainable and affordable manner. However, merit-order-based price effects have a limitation concerning the future applicability of results as quantified effects may not be permanent when the electricity system adapts.

This paper connects industrial self-supply and the merit-order effect within a nodal energy model. It provides insights into the relevant interdependencies and reciprocal effects by means of a simulation.

The purpose of this study is to analyze the power market and greenhouse gas (GHG) emission effects of the joint Norwegian–Swedish tradable green certificates (TGCs) market, which is established to support investments according to a 26.4 TWh increased annual renewable electricity generation (REG) by 2020.

The study applies an energy system model with high granularity in time and space, and detailed power system data for the Nordic countries, Germany, The Netherlands and UK.

The results show that the TGC scheme will cause a 8.7-9.3 /MWh reduction in average electricity prices in the Nordic countries. The price decrease will to a limited extent pass through to Germany, The Netherlands and UK. When assuming a low carbon price level, the new REG will reduce annual GHG emissions by 10.9 Mtonnes in 2020, primarily through substitution of German natural gas power. A sensitivity analysis shows that the GHG emission effect of the TGCs is highly sensitive to changes in the carbon price. Investment levels up to a 90 TWh increased REG per year are found to cause increasing GHG emission reductions.

The study results signal the importance of taking the TGC policy into account in decision-making processes in the Northern European power system, in particular for market actors in the Nordic area. The authors conclude that the Nordic countries potentially can play a vital role in a future Northern European low carbon power system through export of green balancing power, substitution of thermal power and reduced GHG emissions from the Northern European power sector.

The United Kingdom (UK) Government is required to meet various renewable energy targets set by the European Union. The UK has had renewables support schemes for many years. It has become clear that the old schemes are insufficient to lead to enough new capacity to meet the target. The government has accordingly reformed the renewables obligation (RO). The purpose of this paper is to analyse whether the reformed RO will meet the targets set for 2015 and 2020.

The paper undertakes a review of the modelling literature and performs a critical, deductive analysis of the RO to answer its research issue.

The paper finds that it is too late to make any difference to the 2010 target, but that the reforms might lead to the 2015 target being met, and finds that whilst it is clear that the reformed RO will lead to more capacity being built than otherwise would have been the case, it is difficult to establish that the 2020 target will be met.

This paper shows that there may be further reform of the already‐reformed RO, and that more time is needed to see the impacts of the recent regulatory responses to the external failures. This understanding will be useful in developing new policies to promote renewable energies in the UK.

The purpose of this paper is to explore grid‐based routing in wireless sensor networks and to compare the energy available in the network over time for different grid sizes.

The test area is divided into square‐shaped grids of certain length. Energized nodes are placed randomly in the terrain area with the sink node in a fixed position. One node per grid is elected as the leader node based on the highest energy level and the proximity to the centre of the grid. The sink node floods the network to identify a path from sink to source. The path from the sink to the source through the leader nodes are computed using three different methods: shortest path; leader nodes which have the highest energy; and leader nodes based on their received signal strength (RSS) indicator values. After the path is computed, transmission of data is continued until the leader nodes run out of energy. New leader nodes are then elected using the same mechanism to replace the depleted ones.

Identified the optimal grid size to minimize the energy consumption in sensor networks and to extend the network lifetime. Also proposed is a new routing protocol which identifies routes based on energy threshold and RSS threshold.

The use of RSS threshold is identified to be the good metric for path selection in routing the data between source and the sink.

Simulator software and the protocol developed can be used for in optimizing energy efficiency in sensor networks.

This work contributes to the discussion on uniform and non‐uniform grid sizes and emphasizes a new method for reducing the energy consumption by identifying an optimum grid size. It also utilizes bursty data for simulation.

This article reviews the telecommunications environment and infrastructure, discusses the major forces influencing change within this environment, and suggests certain likely outcomes, as seen by the author, that will have significant influences on the future telecommunications infrastructure. This information is then used as the basis for assessing likely impacts on various aspects of library and information systems, their providers and users. Specifically discussed are impacts foreseen for: 1) national online information providers; 2) local online information providers; 3) local and long‐distance telephone companies as providers of information; and 4) users of information. Impacts on library and information system‐related endeavors are seen to be generally unfavorable in the near term, with information delivery costs seen to rise significantly in the next three to five years. A more favorable prognosis, however, is seen for the longer term.