The value of Interconnection in a Changing EU Electricity system

Lead Research Organisation: University College London
Department Name: Bartlett Sch of Env, Energy & Resources

Abstract

Investing in new European interconnection capacity is one strategy to integrate renewables and nuclear power stations in the electricity systems of GB and Ireland, by maximising their value through exports and meeting demand peaks through imports.

This project aims to assess the value of UK interconnectors to the EU-27 and Norway, examining both the GB and the Irish Single Electricity markets, by investigating five hypotheses:

1. Expanding GB-linked interconnectors would reduce the cost of electricity for both the UK and the EU-27.
2. The operational value of interconnectors will be affected by post-Brexit market relationships (e.g. the GB relationship with the European Energy Union and the Irish Single Electricity market).
3. Balancing markets could be an important future source of revenue for interconnectors.
4. Previous interconnection modelling studies have misinterpreted spurious correlations caused by continent-wide increases in renewables and other system evolutions.
5. The optimal level of investment in GB and I-SEM interconnectors, and between Northern Ireland and the Republic of Ireland, in terms of both security and cost, will be affected by the outcome of Brexit negotiations.

The ETM-UCL European energy system model and the ANTARES European electricity dispatch model are being used to assess the potential benefits of existing and new interconnection between the UK and the EU-27 and Norway, for a range of post-Brexit policy environments. The impact of interconnectors and renewables on electricity system stability is being assessed.

The GCDCN model, adapted from neuroscience, is being developed to identify causal relationships between interconnection investments and price variations across UK and EU-27 markets. This provides a foundation for improving regulatory models and investment business case analyses.

Planned Impact

Renewable and nuclear electricity generation is expected to have an important role in reducing UK greenhouse gas emissions to achieve the 80% reduction by 2050 enacted by Parliament. The Lords Science and Technology Committee 2014-15 Session highlighted evidence that increased interconnection could bring significant benefits to the UK electricity system, by enhancing resilience and decreasing the costs of electricity in the wholesale market. The UK Parliament and the UK Government are interested in more detailed analysis of the potential value of interconnection.

The UK has large potential renewable resources and interconnectors could facilitate a thriving electricity export industry in the future, underpinning green jobs in renewables and potentially increasing UK energy independence. The Scottish and Welsh Governments will benefit by understanding whether interconnectors can underpin greater investments in renewable generation in their jurisdictions, where renewable resources are particularly large.

The UK Government has specifically identified the "potential contributions to system balancing [by interconnectors]" as an area in which they need further scientific evidence. This project will provide evidence about adequate levels of interconnections for the GB and Irish systems in the longer term, how these would be affected by political decisions and the transition to low-carbon electricity systems in different countries, and what the implications would be for security of supply. The system operator, National Grid, will benefit from understanding the implications of interconnectors for system stability and are keen to better understand the uncertainty that they identify about future interconnectors in their letter of support.

The Government faces challenging Brexit negotiations with the EU-27 about the future relationship between the GB, Irish and continental electricity markets. Parliament has asked BEIS to open an inquiry on negotiation priorities and has recommended that these include interconnections. Little evidence is available to inform investment decisions in the long term. This proposal will provide evidence on the implications of different options for both the UK and EU-27, including the potential for UK electricity exports to EU-27 markets in the medium to long term under different political and market environments.

Interconnectors are an important area for electricity regulators, with Ofgem having a statutory role in regulation and UREG co-regulating the Ireland Single Electricity Market. Both organisations have joined the Advisory Board of this project because of the potential for it to produce important insights to underpin their work.

The analysis of interconnection business cases will be more comprehensive than was previously possible due to the use of the innovative GCDCN model, to enable better investment decisions that reduce the future cost of low-carbon electricity to consumers. This will benefit large industrial owners and operators of interconnectors such as National Grid Ventures, Scottish Power and Transmission Investment, who are all project partners. The research on public and private benefits will provide the appropriate information to the UK Government so it can ensure that consumers do not lose out from interconnector investments.
 
Description The GB electricity system is connected to France, Netherlands and Ireland. The markets are all coupled, which means final prices are calculated in each market at the same time using the same system, to maximise the efficiency of the flows and minimise market costs. Prior to 2018 (Ireland) and 2014 (France), markets were not coupled. The impact of market coupling on interconnector operations has been assessed through careful data processing and analysis of trading data, covering several interconnectors in multiple years. This analysis has been complemented by a detailed review of how interconnector trading functions in coupled and uncoupled markets, by a former trader. This has enabled us to put a value on the existing GB interconnectors, and also to develop a route to model the implications of market uncoupling in the future when there could be substantially greater interconnection capacity, which is a key goal of this project.

A European-scale electricity market model has been developed using the ANTARES electricity dispatch modelling system to assess the impact of increasing levels of interconnection out to 2030 on the GB electricity sector and on overall carbon emissions across Europe. A UK carbon tax, such as the carbon price support mechanism, raises GB generation costs relative to neighbouring countries and drives higher levels of imports. Planned increases in interconnection in the near term will likely cause higher imports, a reduction in the average GB market price and a significant reduction in GB carbon emissions. However, overall emissions across Europe are relatively unchanged or may even increase in the short term, because highly-polluting coal and lignite might gain increased market share on the continent as exports to GB increase. Scenarios for 2025 and 2030 show that a levelling of carbon prices between GB and its neighbours and an evolving system background with increased renewable generation leads to GB market prices becoming relatively lower in comparison with its neighbours. This could lead to more balanced levels of imports and exports in future years, with GB becoming a net exporter in some scenarios. Increasing levels of interconnection are shown to reduce the spread of hourly price differences between GB and its neighbours, which has a cannibalising effect, reducing both the utilisation of interconnectors overall and the direct revenue opportunities that are available when they are in use. This suggests that remuneration strategies may have to evolve in the coming years to incentivise future interconnectors into the market.

System non-synchronous penetration (SNSP) has been investigated for the GB network by feeding system stability limits on renewable/interconnector electricity into the ANTARES European electricity dispatch model. This has shown that following the construction of new interconnectors, renewables would have to be constrained for much of the year in the GB network under existing Rate of Change of Frequency (RoCoF) regulations. The relaxation of those regulations from 0.125 Hz/s to 0.5 Hz/s in 2020 will have helped, but renewable constraints will still be required, and these could substantially increase the marginal price of electricity above existing long-term forecasts.
Exploitation Route The research on system non-synchronous penetration (SNSP) will assist National Grid with understanding the implications of changing the Rate of Change of Frequency (RoCoF) regulations.

The European electricity system model will be further developed and used in by the UK Energy Research Centre Phase 4. The European energy system model is being used to examine electricity and hydrogen trading across Europe by the H2FC Supergen Hub.
Sectors Energy,Government, Democracy and Justice

 
Description Using a dynamic model calibrated for the GB system, system non-synchronous penetration (SNSP) has been characterised for GB in terms of the magnitude of a possible loss of infeed, the maximum Rate of Change of Frequency (RoCoF) permitted by industry regulations and the amount of frequency containment reserve required to respect the RoCoF limit. This characterisation used in the ANTARES European electricity dispatch model to assess how system frequency stability considerations would constrain the utilisation of renewables in GB and interconnector imports. This has shown that following the construction of new interconnectors, output from renewables would have to be curtailed for much of the year in the GB network under existing Rate of Change of Frequency (RoCoF) regulations. The work helped to demonstrate the benefits of a proposed change of limits from 0.125 Hz/s to 0.5 Hz/s. The regulations have subsequently been revised and protection settings on distributed generation have been in the process of being updated since 2020. In addition, the dynamic model has been used to assess what happened in a system incident on 9 August 2019 that led to electricity supplies to 1.1 million customers being disconnected through the action of 'low frequency demand disconnection' (LFDD). The model has also been used in with the GB system operator, NGESO, to test proposals for revision of the configuration of LFDD. Brexit led to the UK leaving the EU Integrated Electricity Market. Uncoupling the GB market from EU markets was forecast prior to Brexit to lead to a social cost of up to £500m/year. A paper from this project used forecasts of price differences and trader positions to estimate a much lower social cost of uncoupling of €28m/year, and experience since uncoupling validates this finding. The British Carbon Price Support imposes higher carbon taxes on GB electricity generators than those in the EU. Two papers in this project have examined the loss of GB generation due to these taxes, using two different methods (an analysis of historic price data, and the ANTARES European electricity dispatch model for future scenarios). Both demonstrate that imported electricity has higher embodied emissions than GB generation and hence these taxes have caused "carbon leakage". Around 16% of the CO2 emissions reduction in GB is undone by France and The Netherlands, with a monetary loss of about €584m/year to UK generation.
First Year Of Impact 2019
Sector Energy
Impact Types Economic,Policy & public services

 
Title EU TIMES model 
Description A new EU TIMES model was created to produce scenarios of long-term interconnection investments across Europe. The starting point was the JRC-EU-TIMES model. A range of improvements to the model were made to better represent interconnector investment costs and performances, and electricity trade and use. Moreover, improvements were also made to the electricity sector more widely to incorporate hydrogen and electricity system integration, for example using hydrogen turbines for peak power generation. Scenarios from this model on interconnection are being prepared. 
Type Of Material Computer model/algorithm 
Year Produced 2021 
Provided To Others? No  
Impact None yet.