EirGrid (Ireland)

As transmission system operators on the island of Ireland, EirGrid and SONI are significantly involved in implementing multiple projects aimed at facilitating the integration of renewable resources in the all-island power system. One such key project is to develop necessary tools and technologies to enable safe and secure operation of the power system with instantaneous non-synchronous renewable penetration (quantified using the System Non-Synchronous Penetration (SNSP) metric) levels of up to 75%. This paper presents key findings of detailed technical studies carried out in the domains of voltage, frequency and rotor angle stability to conclusively establish whether operating the all-island power system at SNSP levels of up to 75% has any adverse impact on relevant operational security standards. The studies are carried out using selected system snapshots from a trial period involving 200 hours of system operations with SNSP levels greater than 70%. Both base case and sensitivity studies are conducted, and detailed discussions are presented to establish the root cause behind insecurities observed, if any. Based on the detailed analyses presented, a recommendation is made for implementing system operations with SNSP levels of up to 75% on an enduring basis.

The current research on green hydrogen can focus from the perspective of production but understanding the demand side is equally important to the initial creation of a hydrogen ecosystem in countries with low industrial activities that can utilise large amounts of hydrogen in the short term. Early movers in these countries must create a demand market in parallel with the green hydrogen plant commissioning. This paper presents research that explores the heavy-duty transport sector as a market-of-interest for early deployment of green hydrogen in Ireland. Conducting a survey-based market research amongst this sector indicate significant interest in hydrogen on the island of Ireland, and the barriers the participants presented have been overcome in other jurisdictions. The study develops a model to estimate 1.) the annual hydrogen demand and 2.) the corresponding delivery cost to potential hydrogen consumers, either directly or to central hydrogen fuelling hubs.

The primary objective of a power system is to safely provide reliable energy services to society at an affordable cost. In many countries, this objective has been supplemented by another: meeting the energy demand with sustainable resources, which has culminated in the energy transition to low-carbon and zero-carbon energy systems. This transition, occurring rapidly around the world, is characterized by the increasing penetration of variable renewable energy (VRE), inverter-based resources (IBRs), and distributed energy resources (DERs).

This paper presents a case study using the Electric Power Research Institute's Grid Strength Assessment Tool to screen Ireland's system for potential weak grid issues. The tool calculates system strength metrics as well as the critical clearing time of the inverter-based resources without the need for dynamic simulations. The case study identifies areas that may potentially be susceptible to controller instability where more detailed analysis is warranted. The effect of different assumptions for controller gains for inverter-based resources is investigated.

Variable renewable generation technologies such as wind and solar photovoltaic have introduced new challenges in power system management. Grid operators have traditionally used ancillary services such as reserve and reactive power to help to maintain a secure and reliable power system. In addition, conventional synchronous generators have inherent characteristics such as inertial response, which help the power system to recover after an event. In Ireland and Northern Ireland, a weakly‐interconnected island system with a high penetration of wind, new ancillary or ‘system’ services have been devised to address the technical scarcities arising from the displacement of synchronous generation. Twelve system services addressing the frequency and voltage control needs have been procured to date, allowing the power system to be operated with up to 65% instantaneous non‐synchronous renewable power on the system. This study outlines the implementation of the innovative system services framework. It includes an overview of the services procured and examples of the changed behaviour of existing units in response to financial incentives. It also examines how new technologies have responded to the signals provided, questions how aspects of the arrangements may be further improved and details the challenges of integrating the use of these innovative services into operational policy.

The use of systemic glucocorticoids (GCs), as well as local injections, continues to be a controversial issue in the sport/anti-doping community. There is widespread and legitimate use of GCs for numerous health conditions, yet there are concerns about side effects and the possibility of enhanced athletic performance in limited settings. This is compounded by the uncertainty regarding the prevalence of GC use, mechanisms underlying physiological effects and complex pharmacokinetics of different formulations. While WADA continues to promote research in this complex area, some international sporting federations, major event organisers and professional sports leagues have introduced innovative rules such as needle policies, mandatory rest periods and precompetition guidelines to promote judicious use of GCs, focusing on athlete health and supervision of medical personnel. These complementary sport-specific rules are helping to ensure the appropriate use of GCs in athletes where overuse is a particular concern. Where systemic GCs are medically necessary, Therapeutic Use Exemptions (TUEs) may be granted after careful evaluation by TUE Committees based on specific and strict criteria. Continued vigilance and cooperation between physicians, scientists and anti-doping organisations is essential to ensure that GC use in sport respects not only principles of fairness and adherence to the rules but also promotes athlete health and well-being. The purpose of this narrative review is to summarise the use and management of GCs in sport illustrating several innovative programmes by sport leagues and federations.

Large scale Demand Response (DR) has different impacts on different market actors. The impacts depend significantly on the market actor and the operational environment. The impacts of DR on electricity retailers (ER) in the North-European electricity market are discussed in this paper. DR is a double-edged sword for an ER. On one hand, DR offers a potential tool to improve the operation in the electricity market, but on the other hand, DR poses also risks to the ER. The impacts of DR on ERs depend on many things like the nature of the controllable demand, the characteristics and the rules of the market place in which DR is being operated and the structure and the nature of the electricity contracts made with the customers. These things are discussed in depth in this paper. A case study is presented related to DR based on day-ahead area prices in Finland. The case study shows that on average, the imbalance costs induced by DR to the retailer can even be positive (positive cash flow), but the risk of significant additional costs remain and might even be increasing.

Abstract Constructing a power network model for geomagnetically induced current (GIC) calculations requires information on the DC resistances of elements within a network. This information is often not known, and power network models are simplified as a result, with assumptions used for network element resistances. Ireland's relatively small, isolated network presents an opportunity to model a complete power network in detail, using as much real‐world information as possible. A complete model of the Irish 400, 275, 220, and 110 kV network was made for GIC calculations, with detailed information on the number, type, and DC resistances of transformers. The measured grounding resistances at a number of substations were also included in the model, which represents a considerable improvement on previous models of the Irish power network for GIC calculations. Sensitivity tests were performed to show how calculated GIC amplitudes are affected by different aspects of the model. These tests investigated: (1) How the orientation of a uniform electric field affects GICs. (2) The effect of including/omitting lower voltage elements of the power network. (3) How the substation grounding resistances assumptions affected GIC values. It was found that changing the grounding resistance value had a considerable effect on calculated GICs at some substations and no discernible effect at others. Finally, five recent geomagnetic storm events were simulated in the network. It was found that heavy rainfall prior to the 26–28 August 2015 geomagnetic storm event may have had a measurable impact on measured GIC amplitudes at a 400/220 kV transformer ground.