On Thursday, September 26th, ESO held its quarterly Balancing Programme update. The webinar included a recap of changes and improvements made to the Balancing Programme over the past three months.
The webinar reviewed how increased utilization of batteries and small BMUs in the Balancing Mechanism via the open Balancing Platform (OBP) has led to increased dispatched volume.
It also covered upcoming changes to the Open Balancing platform (OBP) and other systems to move towards a whole-system view. This includes improvements to tools for constraint management and the development of a National Optimizer. It also detailed updates to its energy forecasting and the progress made on forecasted wind generation.
The full roadmap for the next twelve months can be found at the end of this article.
Improvements to Balancing Systems since June
Since the last update in June, ESO has progressed across several aspects of the Balancing Mechanism.
Open Balancing Platform saw record-breaking battery usage
August saw the highest battery volume instructed through OBP and the highest battery volume ever recorded. In August, the control room dispatched 81 GWh of battery volume, with 73 GWh actioned through the OBP.
As a result, batteries also earned their highest Balancing Mechanism revenues ever.
Quick Reserve to increase contracted battery capacity
During the past three months, ESO have completed the work required to make the OBP compatible with the new Quick Reserve service. As a result, the first delivery is expected in early Decemeber with the auction platform made available 14 days prior, in late November. The new service will procure a minimum of 300 MW, reducing total unreserved battery capacity.
Reduced voided instructions from the control room
In March, 6.1% of battery dispatch instructions were voided by the control room, accounting for 3.5% of all instructed volume. Voided instructions occur when a given output is not possible. For example, the input data to the system may include decimal point data, but the system can only handle integer values. This may create an instruction that has to be voided. These are then manually corrected, reducing efficiency.
By reducing voided instructions, ESO saw improved utilization of Balancing Mechanism units through OBP. By 15 August, voided battery instructions had reduced to 0.2%, just 0.01% of the instructed volume.
Improvements to wind forecasting
ESO has been improving its wind generation forecasting as part of the Platform for Energy Forecasting release plan. Improvements to forecasting here can enable better battery optimization in the Balancing Mechanism.
Open Balancing Platform system updates
ESO has begun work on two interfaces to improve dispatch efficiency in the Balancing Mechanism. One is the Integrated Energy Management System (IEMS) interface, which will support better constraint management. The second is the Single Markets Platform (SMP) interface. This will allow new services to become available in OBP and give the Control Room better visibility over what other markets units are contracted in.
The battery zone could soon receive larger instructions
In October ESO plans to release an update to balancing systems that could see the amount of power the battery zone is advised to deliver increase.
Engineers in the control room receive advice from legacy systems on what actions may need to be taken by which zones. Zones describe different types of units in the Balancing Mechanism. These can be based on technology or location. For most zones this advice is calculated through an algorithm, however, for the battery zone, this is calculated through a manual process.
Engineers use the advice to instruct the individual unit(s) within a zone. For the small BMU and Battery zone, engineers can additionally use OBP to optimize a set of instructions to be created and sent (which is not manual).
As shown in the previous charts, the majority of battery volume is now dispatched through OBP. OBP has algorithms that underpin it.
Legacy systems: Improved algorithmic process to model batteries
The developed update is to the current advice algorithm within the legacy Balancing Mechanism system, the legacy Dispatch Algorithm (LDA). This will remove a limitation that the algorithm cannot currently support batteries as it cannot advise them to go from exporting to importing or importing to exporting. It also gives advice four hours ahead of time. However, batteries are limited to 30 minutes of known available power through their Maximum Import and Export Limit data.
The update would see the battery zone be given bi-directional advice utilizing the full range between MEL and MIL. This advice will be time-limited.
The benefits of this new update means that the battery zone can receive advice for bids and offers at higher powers. As a result more batteries could be dispatched at the same time or given higher power individual instructions.
For example, this was shown in a test run on an evening with high wind generation. The ESO saw the total power advised to be delivered from the battery zone for bids at a given time increase from 20 MW to over 1 GW. The advice to bid down wind generation was also reduced by 1 GW.
In 2025 a National Optimizer is set to replace LDA. This will also include constraint advice.
Improvements to constraint management workflows in the Balancing Mechanism
ESO does not manage constraints through the Open Balancing Platform (OBP). It manages them using legacy systems. By Q4 FY24/25, ESO aims to move constraint management into OBP. In the meantime, ESO is working on new flows to improve the dispatch of units behind a constraint and relax the restrictions on using a unit for energy actions.
Units inside a constraint are flagged so that they will not be actioned. This flag can remain even after the constraint has been fixed. This can be done to avoid recreating the constraint.
The new systems seek to give control room engineers increased constraint tracking capability. They will also have tools to investigate the most cost-effective combination of units that can manage the constraint without creating new constraints elsewhere. To understand more about how constraints are managed the ESO have released this video.
Batteries are being used more often for constraint management in 2024, as seen in an increase in system-flagged dispatched volume and a reduction in system-flagged skip rates.
However, constraint-based skips have not fallen at the same rate as energy-based skips. In December 2023, the skip rate for batteries based on energy actions was 92%. In August 2024, this was reduced to 73%. Skip rates based on constraints decreased from 97% in December 2023 to 91% in August 2024.
ESO has identified its main focus areas for the next twelve months
Over the next 12 month, ESO has highlighted some main areas of focus. This includes proven OBP robustness, enabling both BM and non-BM services to be managed on a single platform, the retirement of legacy systems, improved constraint optimization and national optimization.
