In 2016 the National Grid published a document that showed the status of interconnectors and brief plans and targets for the future. At that time the maximum power available to GB from the interconnectors in operation was about 3 GW.
In that document a potential for 15 to 20 GW of power was mentioned, although GB now intends to use up to just under 30 GW by 2050.
This document from Ofgem shows a recent list of the current and some of the planned interconnectors.
All National Grid scenarios include an increase in the use of interconnectors. However, there are some particular issues associated with their use.
According to the National Grid figures in coming years interconnectors will fulfil an increasing role in providing electricity when intermittent sources are unable to.
The figures also show GB using interconnectors to export excess generated electricity, which would help to offset the cost of the imports and contribute to the general harmonisation of power generation and supply in Europe.
In January 2021 there were 8 interconnectors either being used or about to be used by Great Britain. Here are the details:
|Name||Partner Country||Capacity (GW)||Commissioning date||Partner Country major electricity sources||Electricity source data year
|Britned||Netherlands||1.0||2011||Gas 59%, Renewables 19%, Coal 14%, Other fossil 3%||2019
|East-West||Ireland||0.5||2012||Gas 54%, Wind 16%, Coal 11%, Peat 10%, Other renewables 5% ||2018
|ElecLink||France||1.0||2019||Nuclear 71%, Hydro 10%, Gas 7%, Wind 6%, Solar 2%, Bio 2% ||2019
|IFA||France||2.0||1986||Nuclear 71%, Hydro 10%, Gas 7%, Wind 6%, Solar 2%, Bio 2% ||2019
|IFA2||France||1.0||2020||Nuclear 71%, Hydro 10%, Gas 7%, Wind 6%, Solar 2%, Bio 2% ||2019
|Moyle||Northern Ireland||0.5||2002||Gas 43%, Renewables 42%, Coal 14%||2018
|Nemolink||Belgium||1.0||2019||Nuclear 49%, Gas 27%, Wind 10%, Solar 4% ||2019
|NSL||Norway||1.4||2021||Hydro 93%, Wind 4%, Thermal 2% ||2019
How clean is it?
In many cases the electricity imported via interconnectors will have been generated from fossil fuels.
Electricity imported via interconnectors from a "source" country and used in a "destination" country is counted as zero carbon from the perspective of the destination country. In the case of GB this means that electricity that has been generated from fossil fuels can be imported without affecting our claim to be "zero carbon".
Current interconnector "source" countries include France - where most electricity generation is nuclear - and Belgium, Ireland and the Netherlands, all of which still use significant amounts of fossil fuels to generate electricity, as you can see from the table above.
Given Great Britain's anticipated dependence on interconnectors, should we really ignore the fossil fuels used to produce the electricity they deliver as we strive to be "zero carbon", even though the rules say that we can?
How much will we really export?
As the National Grid figures show, we expect to roughly balance interconnector imports and interconnector exports as we move into the future.
However, exports so far have been at a very low level, and there is no immediate evidence of them increasing to start to "catch up" with imports.
Where can we obtain an explanation and quantification of this increase in exports?
How much will we really import?
However, the need for the imports is already very real, as in many cases imports via the interconnectors are already needed to help to "plug the gap" produced by intermittency.
During the UK Spring 2020 Covid-19 lockdown for example - when electricity demand was running at a reduced level - for almost every day imports via each of the major interconnectors (French, Dutch, Irish, East-West and Belgium) reached their maximum at some point.
Will it be there when we need it?
Given the issue of even more intermittency due to our increased reliance on intermittent sources, we are likely to need interconnector imports more often and in greater amounts. Although the capacity agreements will have established overall quantities for import and export, they do not deal with the issue of whether interconnector "partners" will be able to provide us with electricity at a specific point in time.
This issue is dealt with in some detail in this document, but it certainly does not conclude that we can always count on imports via interconnector whenever we need them.
One of the statements in that document is "Historically interconnectors would be available 75-95% of the time for the currently connected or due to be connected countries."
By increasing our dependence on interconnectors are we not making it even more likely that at a time of need we will be most likely to use electricity from fossil fuels?
Clearly our dependence on interconnectors - which is already a reality - significantly reduces our level of energy security. Without the current relatively small amount of power available from interconnectors we would already be experiencing more frequent power outages. As our dependence on interconnectors increases, so will our consequential loss of energy independence and security.
Conversely, if Great Britain experiences unexpected difficulties with supply there will be a chance that interconnectors can "fill the gap". From this point of view it can be argued that interconnectors increase our security of supply.