Emily Gosden, the Energy Editor at The Times, this morning posted a number of tweets about National Grid’s management of the electricity system, given the big drop in energy demand caused by Coronavirus. Our Dispatch reports have previously highlighted the fall in demand and the market’s response but we thought it might be helpful to provide some additional information.
As Emily rightly pointed out (and as we flagged in our latest Weekly Dispatch), last weekend National Grid experienced their lowest ever demand at 15.2GW. This event was manageable, thanks to interconnectors being scheduled to flow out 2GW by the market; however if this had been the other way around the situation would have been much harder to manage as the number of synchronous machines would have been far fewer.
In the recent Summer Outlook Report, National Grid warn of the potential to issue national NRAPM warnings (Negative Reserve Active Power Margin) something that so far has never been used.
This is a warning asking generators to provide more flexibility to move their output lower; if this cannot be achieved then it is likely the system operator will issue emergency instructions to turn off inflexible generation to allow the flexible generators to remain synched to the grid.
This is in line with Grid’s recent call for the super SEL service (i.e. reducing the lowest level of output a power station can safely achieve) as this is a way of providing more negative margin. Grid have also been actively investigating the ability for embedded generation (i.e. those not directly connected to the transmission system) to turn off to help with periods of low demand.
The Easter weekend saw National Grid buy on up to 17 units to manage inertia and margin issues, this highlights the problem proving that it is not an oversupply of generation that is causing issues rather it is a lack of flexibility and inertia over periods of low demand.
As you can see, Grid is working closely with industry players to best manage the system during these unprecedented times, and all of us at Limejump are playing our part to support Grid and our customers. If you would like to know more please contact us or speak with your account manager.