Project Summary
A key milestone in the UK's 2050 net zero commitment is to decarbonise the UK's electricity system by 2035. Ensuring our electricity networks are effectively
utilised to support this ambition is of upmost priority.
In this project we are revaluating the assumptions in the design and operation of demand and generation connections to the GB electricity distribution network to explore if the existing system could be utilised more efficiently. By exploiting the rich, emerging vein of high volume, real/near time energy data from both sides of the connection, can we unlock capacity and remove/manage constraints and enable swifter new-connections timelines?
Innovation Justification
Traditional approaches to distribution network connection queue management predominantly rely on uniform frameworks. These use fixed values for capacity based on maximum export and/or import to account for the safety and control requirements of the network operation.
But there is often diversity in the generation or demand export/import profiles. Spatial, temporal and seasonal variations aren't accounted for in the traditional one-size fits all approach. Taking advantage of these 'diversity factors' - distinctive attributes of the connection, during new connection grid capacity assessments could unlock more optimised resource allocation. While diversity factors have been considered when modelling demand at the low voltage level of the
distribution system in the past, no such systematic approach has been adopted for generation or demand at higher voltage levels.
A comprehensive and adaptable framework is necessary to integrate any consideration of diversity in connections queue management. A novel methodology for effective assessment and utlisation of headroom at GSPs was developed within the Discovery Phase of the project. The objective was to explore the untapped capacity that can be harnessed by means of incorporating the diversity and actual power output of RES and storage. The two major innovations can be described as below:
Conventionally, the rated power has been utilised for the calculation of headroom -- a conservative approach to ensure the firm capacity at the GSP is never breached. This leads to suboptimal resource allocation and under utilisation of the distribution assets in some instances. Incorporating diversity factors derived from analysis of historical and real-time power flows will enable the calculation of dynamic headroom at the GSPs. This innovation evolves the conventional planning, operation, and control at the GSP that has been in practice for decades.
Taking into account the renewable resource and spatial characteristics of the connection type more accurate assessment and forecast of the power flows can be carried out.
In the Discovery Phase, the hypothesis that diversity and flexibility in grid connections can effectively release benefits to the connections queue was verified. High level analysis was conducted relying upon publicly available data and relatively unsophisticated models of RES output and storage impact.
The Alpha Phase of the project aims to take a deeper dive into the available network data to validate the approach through utilising real-world data from specific GSPs, the distribution network and asset owners connected in those areas. The project will use statistically led data analysis methods to derive the diversity factors.
If the methodology is verified, the approach will become an integral part of NPg's Business-As-Usual (BAU) toolkit for managing constraints and connections queues, resulting in ongoing benefits for customers. Additionally, the knowledge gained from the project will be shared with other network companies, leading to further customer benefits across the industry.This project builds upon the ongoing work of ENA strategic connections group. Furthermore, engagement with key stakeholders and review of existing policies and literatures during the Discovery phase has confirmed that this innovation will be complementary to the Five Point Plan published by National Grid ESO. In particular, the Five Point Plan's goal to reduce the number of stalled projects in the queue via code modifications and the TEC amnesty. The plan also seeks to change how storage is treated in the connections process, to reflect the unique nature of its operation, provides scope for storage to connect to the network under non-firm contracts. These initiatives
align with the diversified flexible queue management project. An approach based on dynamic headroom assessment represents a step beyond the current measures and has scope to significantly improve the whole system utilisation of the transmission and distribution networks.
Impacts and Benefits
This project has the potential to deliver a significant impact on reducing queues for connections onto Distribution networks.
1. Financial - future reductions in the cost of operating the network
Currently, network reinforcement would be sized to accommodate, at a minimum, capacity requirements of new connections. Using a data driven approach to identify network capacity will reduce the level of reinforcement needed or avoidance of the reinforcement entirely by unlocking flexibility from the connection stage and prioritising connection of the most flexible assets.
The impact of this will be measured through a cost benefit analysis that compares the counterfactual against the different use cases. Real world operation data will be used if applicable from partners.
2. Financial - cost savings per annum on energy bills for consumers
Extrapolation of the impact of network reinforcement savings to customer bills, based on the current charging methodology that assigns costs to different voltage levels on the basis of network use factors and assumptions of downstream only flows will be carried out.
3. Financial - cost savings per annum for users of network services
It is anticipated existing users would benefit from faster connections, allowing their connection dates to import and/or export sooner than would otherwise be the case.
