Skip to main content
This project ended in Apr 2023 and is now closed.

Solving Intelligent LV - Evaluating Responsive Smart Management to Increase Total Headroom (SILVERSMITH)

Funding mechanismNetwork Innovation Allowance (NIA)
DurationJun 2022 - Apr 2023
Project expenditure£344K
Research areaNet zero and the Energy System Transition
  • South West
  • South Wales
  • West Midlands
  • East Midlands
  • May 2023

    Over the past month, we have been completing the dissemination and closedown process.


  • Understand the issues which are likely to be present on the Low Voltage (LV) network up to 2050. Business As Usual (BAU) activity does not investigate the LV network at this granularity.
  • Document the current state-of-the-art LV voltage control options and evaluate which are likely to meet the functional requirements created in this work.
  • Develop two design methodologies for selecting whether LV voltage control technologies can offer a benefit over conventional reinforcement strategies.
  • Develop an understanding of which network assessment methodology is most suited for modelling issues and forecasting required investment on the LV network.


Initial reviews of ED2 business plans and network models suggest that there will be a number of instances where Low Voltage (LV) networks are on a trajectory to experience both transformer thermal issues as well as non-compliant feeder voltages. Whilst we already have the ability to resolve these issues using conventional means, supply chain engagement indicates that some nascent LV voltage control technologies may offer an opportunity to resolve these issues in innovative ways. Past innovation projects have investigated some of these technologies and built some successful use-cases. UKPN’s ‘FUN-LV’ investigated how power electronics can enable soft open points, Northern Powergrid’s ‘Customer-Led Network Revolution’ investigated on-load tap changers and Electricity North West’s ‘QUEST’ is investigating whole system voltage optimisation. What we are missing, is an understanding of how widespread these LV issues will be, and the extent to which different combinations will need to be resolved individually. There is not a clear methodology for DNOs to use when selecting the most suitable technology or solution. Furthermore, to better prepare for the scale of investment decision making required to achieve net-zero, we want to learn whether a finance based model aptly represents the network, or whether a load-flow based model leads to better investment decision making.


Phase 1: Network evaluation and technology literature study 

To consider a range of approaches, SILVERSMITH will feature analysis using two methods, delivered by separate consultants. Firstly, EA Technology ltd’s (EATL) Net Zero team will perform strategic investment analysis using Transform. This is an Excel based network model that uses 19 LV network archetypes to create representative models of each license area. The tool has been endorsed by Ofgem, and used by all UK DNOs for investment planning due to connected LCTs in ED1. Secondly, EATLs Power System Studies team are performing a power flow assessment. EATL’s Power System Studies team will be completing the analysis to the same scope, but completing a power flow analysis of three representative networks (urban, dense urban, rural) using ConnectLV and DIgSILENT. The later can evaluate power flow phenomena such as harmonics and power factor correction.

This analysis will determine the scale of the issues that are developing on the LV network. These include transformer overloading, cable overloading, and non-compliant voltages. Crucially, we want to understand to what extent these issues coincide. Does a transformer overload typically coincide with a cable overload? In addition, what proportion of feeder cables experience a simultaneous voltage drop, and rise outside statutory limits? And most significantly, what proportion of substations experience all issues. Under different combinations of these issues, novel LV voltage control technologies may outperform conventional means, both at a functional level and price point. Using this network analysis, we want an opportunity statement that specifies ‘if a device can offer X specific functionalities, at a set price point of Y or less, it will outperform conventional means as discussed before’. All proposed technologies will be compared against the current reinforcement method of dealing with compliance issues.

The second half of this phase is the creation of a literature review by EATL’s Net Zero team that documents all available LV voltage control technologies. It should introduce each type of device, explain how each technology operates, what functionality it offers, TRL, estimated price point and where it has been trialled. Either as part of an NIA project or academic setting. In addition, the report must explain the differences between low voltage management compared to other higher voltages. EATL are responsible for delivery, after a Request for Information has been published by National Grid Electricity Distribution (NGED). We will issue an open enquiry into the available technology, in which suppliers can share more information that would otherwise be out of the public domain. With the knowledge that they will gain access to the functional requirements which are produced in this work.

The outputs of this work package are the following deliverables: 

  • D1.1: Network study results (June - September 2022) 
  • D1.2: Literature review of existing technologies (June - August 2022) 

Phase 2: Functional requirements and methodology development 

Providing phase one is successful, functional requirements will be matched to existing technologies and offered to the suppliers we engage with at the RFI. From this, we seek to document our recommendation and devise a methodology to identify where LV control technologies can benefit a DNO. Again, EATL’s Net Zero team and EATL’s Power System Studies team will complete this phase in parallel with a split between depth provided by EATL’s Power System Studies team’s power flow study, and breadth provided by EATL’s Net Zero team’s Transform study.

The outputs of this work package are the following deliverables: 

  • D2.1: Functional requirements (September - November 2022) 
  • D2.2: LV voltage control selection methodology (October - December 2022) 

Extended technology investigation and final recommendations (completed throughout both phases) 

This phase follows the new technologies that are being developed by new and existing suppliers to address LV voltage control throughout the entirety of the project. The technologies that are most likely to meet the functional requirements will be evaluated. Through supplier engagement, we aim to identify the extent to which they meet the functional requirements. In return for assisting with our project, we propose to provide suppliers with the results from our investigation that can help them direct their product’s development in line with our requirements.

The output of this work package is the following deliverable: 

  • D3.1: Technology investigation report (June - December 2022) 

Project Close 

After the analysis in phases 1 & 2, two approaches for network evaluation and design methodology will have been produced. Each will have prioritised varying aspects of the analysis, and as a result some variation between the design methodologies produced is expected. In addition, the specific functional requirements may indeed differ resulting in different technologies being recommended for further use. To conclude the project, NGED will evaluate the overall approach of each consultant has taken and make recommendations for further work. In addition, the usual project closedown report will be produced by NGED.

  • D4.1 (NGED) Methodology Comparison (December 2022 - February 2023) 
  • D4.2 (NGED) Closedown report (December 2022 - March 2023)