Today is the deadline for companies developing new power technologies to apply to be classified as ‘emerging technologies’ and avoid strict new requirements on how they interact with the grid and provide grid services. Ofgem’s information for emerging technologies applying for exemption is here.
Companies have to act because new ‘Requirements for Generators’ mean that even the smallest generators will have to help manage the system in future.
The change should reduce costs overall, but may increase costs for some generators. For some it means new product standards, for others it means active participation. Where will the lines be drawn?
Because the electricity system now has increasing wind and solar generation and high-voltage direct current (HVDC) interconnection, there is less so-called inertia in the system and that makes it more difficult to keep voltage, reactive power and frequency within strict limits.
In future, even the smallest power generators will have to act in a way that is beneficial to the system. Larger ones will have to contribute to ancillary services during disturbances and assist in restoring the system after blackouts.
Who does what?
So-called Requirements for Generators (RfGs) will apply to all generation from 800W upwards. But requirements vary depending on the size of the installation.
At the smallest scale (potentially including large households), users will see little practical difference, but the change could raise operating costs substantially for plant rated from a few tens of MW.
RfGs will apply to new plant and any plant that undergoes substantial modification or rebuild.
The smallest installations (so-called Band A) will mostly be affected because product design standards will change to ensure they have beneficial operating characteristics and can react automatically to system stresses. This covers installations rated at 800W to 1MW, which will have to be able to withstand changes in the grid frequency and will be required to limit their own effect on the system.
Band B will also be implemented via product standards. Plants in this band will have to offer automatic functions, including: ‘riding through’ grid disturbances; reducing power when called on to do so; being able to reconnect to the system automatically; and being able to provide ‘reactive power’, which helps maintain the system supply. Band B will cover installations from 1MW upwards.
For owners of larger assets – so-called Band C and D – active response will be required and this could require a change in operating regime.
At the moment it is not clear where that boundary will lie. Ofgem will decide this autumn whether the boundary between Band B and Band C will be set at 30MW or 50MW and whether the boundary between Band C and Band D will be 50MW or 75MW.
Operators with plant in Band C or D will have to provide a suite of services including active control, frequency response, optional black-start services and a number of other options.
Onshore wind and solar farms, energy from waste plants, on-site combined heat and power (CHP) installations and industrial plants will have to comply with the new requirements, as will existing plant that is repowered.
That could increase the capital costs of plant in future. But there are also potential extra operating costs: it may even mean that plant that was previously staffed only in office hours, with automatic monitoring at other times, will have to have 24-hour oversight.
Band D level plant will be required to offer the highest level of services, but many plants at this scale would already be equipped to do so.
Setting the level
National Grid has carried out extensive consultation on banding over the past two years and had responses from generators, trade associations and network operators.
Some argue that the lower bands should be chosen, because they fit more closely with existing requirements in Scotland, which has particular needs for localised voltage control.
But a wider industry view is that bands should be set at the higher level. This is more likely to be consistent with neighbouring markets, so it means manufacturers can produce standard pan-European products and keep costs down.
In its response to an industry consultation on the topic, the Association for Decentralised Energy (ADE) described higher bands as the “lowest risk” option, noting that they “align most closely to the current GB thresholds, which have been demonstrated historically to be at an acceptable level” and will have lower costs.
The industry wants to get banding levels approved before another new piece of the IEM rules is set in place – Transmission System Operating Guidelines (TSOGs). These will require market participants – existing as well as new – to provide regular data to distribution and transmission system operators.
The banding levels will be used to determine which generators must provide what data – and have to bear the associated costs.
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