Project Summary
Superconducting systems have five to ten times higher power density than the equivalent voltage conductor, meaning they deliver higher capacity at lower voltage levels and via a lower number of routes. This will allow faster network capacity increase, delivering time, cost, and carbon savings. Superconducting systems can also deliver a reduction in energy losses to virtually zero and ultimately realise greater environmental benefits. This project aims to investigate these systems in more detail, outlining their operational requirements, technical risks, and next steps in overcoming these barriers for use on the GB grid.
Innovation Justification
This project addresses the challenge theme "novel market and technical approaches to cost effectively minimise renewable energy curtailment" by exploring novel superconductor technology that can provide bulk power transfer for future renewable connections. High-temperature superconductor (HTS) technology can deliver increased power density without increasing voltage, and has the potential to reduce connection lead times, simplify planning (by negating the need for high voltage reinforcements, e.g., 400kV), and reduce upgrade costs associated with ancillary equipment upgrades (e.g. transformers, circuit breakers). The culmination of these has the potential to minimise curtailment and contribute to a faster roll out of renewables.
Building on the learning from previous SIF projects, SCADENT and SCOHL, the project will investigate the next generation of HTS technologies, in DC cable and OHL conductors. More established HTS cable technology have limitations in their applications due to fundamental design principles which restrict long length, direct current, and bulk power deployment. Accelerating HTS DC transmission, could have significant benefits, specifically for future large offshore connections.
SIF funding can accelerate the development of these technologies to overcome previously defined challenges, whilst mitigating future network risks. Benefits include:
- Unlocking superconducting technology for broader grid application increases options for grid planners (vastly increased power densities, DC and AC voltages, overhead lines, buried cables);
- Superconducting transmission lines or cables could be rebuilt in existing corridors to increase capacity five to tenfold;
- New corridors could carry high amounts of power within the same or smaller rights-of-way as incumbent technology (e.g., smaller towers for OHLs, smaller cable trench footprint).
- Superconducting lines could provide low-sag options that consistently carry power despite ambient temperature change - eliminating need to dynamically rate lines and act as a climate mitigation in increasingly warm summers.
- Superconducting DC cables operate in a single bipole configuration regardless of power transfer requirements.
Currently industry standards for superconducting DC cables or OHL do not exist. This project is an essential stepping stone to technology acceptance by UK transmission system operators and their grid planning teams.
The current tiered SIF funding mechanism allows this project to de-risk the technology and assess potential viability for further targeted research and exploration (e.g. potential small-scale demonstrator).
Funding support for these activities is critical to accelerating the required TRL increase and allow next-gen HTS technologies to become a strategic tool for decarbonizing the UK energy system reliably, on timescales that will meet its Net Zero commitments.
A parallel project (utilising NGET's NIA funding) will investigate the potential use cases of these technologies. An overview of these projects alignment in reaching BAU is included in the attachment. The combined outputs from these projects will inform the commercial and technical feasibility of HTS systems on the GB grid, and outline the roadmap for overcoming the technical and commercial barriers to realising an HTS installation on the GB grid. Additionally, SuperNode is currently in the process of working with NGET to test their technology at NGET's Deeside facility.
Previous grid-integrated HTS projects are international, meaning that UK industry is missing the resulting knowledge. Most of these installations are experimental, deploying only short cable lengths and operating at relatively low voltages. This project focuses on the less mature technologies of DC cables and AC OHLs, but builds on existing established knowledge.
The project will deliver whole system value through standardisation of future HTS systems that can be used across GB, lowering the cost of superconducting cable deployment through repeatability and modularity. Current deployments operate at different voltages, based on international grid standards; the project will also investigate whether standardisation at these voltages could be adapted for use in GB.
Impacts and Benefits
This project is looking to deliver the following benefits:
Financial (future reductions in the cost of operating the network) -- These benefits will be realised from three main areas:
1) The reduction in transmission losses due to using superconducting lines;
2) The reduction in network constraints (thereby reducing constraint payments);and,
3) The use of lower voltage infrastructure in place of costly high voltage upgrades.
The latter allows the use of smaller, cheaper substations, and can potentially allow the reuse of existing infrastructure such as towers.
Environmental (carbon reduction -- direct CO2 savings per annum) -- these benefits will be realised from the reduction in transmission losses and the reuse of infrastructure as outlined above. Additionally, the use of lower-voltage systems will allow a reduction in the use of SF6, which is a greenhouse gas 23,900 times more potent than CO2.
Environmental (carbon reduction -- indirect CO2 savings per annum) -These benefits will be realised from the achievement of faster transmission upgrades and quicker new connections, allowing the transfer of more power from remote renewable generation and a reduction in such generation being constrained off.
New to market (products) -- High power HTS systems do not currently exist. VEIR and Supernode are developing solutions, though they are not yet commercially deployed. However, the impetus provided by this SIF project is enabling the companies to invest in an accelerated programme to enable higher voltage solutions get to market faster. Potential access to the Deeside Innovation Centre test facilities via this project will further assist in progressing HTS systems for the GB market.
New to market (processes) -- Previous analysis has shown that there are a number of gaps in the standards that apply to electrical and structural elements of HTS systems, and how solutions could be implemented on the grid. This project will investigate how to best address these gaps, and in doing so will potentially provide benefits for other future network upgrades by developing processes in this area. This project could also enable a novel solution for updating existing cable and OHL infrastructure, reducing connection lead time and leading to faster demand (and supply) connections.
