Derated Margin Progression
About
This chart tracks the evolution of the de-rated margin over time. Where the de-rated margin drops below 2GW, it can push system prices up towards £6,000/MWh (the Value of Lost Load - VoLL).
This happens because once the De-Rated Margin drops below 2GW the Loss of Load Probability that is calculated from this de-rated margin figure starts to increase above zero. STOR actions are then re-priced in the system price calculation at £6000 * LoLP. Updates on these LoLP values are fed through on the activity feed when these are non-zero.
When the De-Rated Margin value reaches zero the LoLP
reaches 0.5 (ie actions are repriced at £3000/MWh) and gets close to 1 when the De-Rated Margin
reaches -2GW.
Included Data
This chart shows the progression of the De-Rated Margin
through iterations to its final value over time.
The noon value plots the original noon day ahead estimate and then the other values shown are the updates at set points from the start of the settlement period. When the de-rated margin values start low, these generally increase over time as National Grid increases levels of spare margin in the market.
The De-Rated Margin saw it's biggest impact on the market on a day when National Grid was sufficiently comfortable operating at a lower level of margin to not turn on coal/CCGT plants that were able to come online but at a very high offer prices. Running the market without these plants reduced the margin and also increased the use of STOR in the market, with this STOR activity then re-priced well above it's normal pricing levels.
Data Service
The data for the Derated Margin Progression chart can be extracted from the API. The parameters are as follows:
| Code |
Required/Optional |
Description |
| chart |
Required |
deratedmargin |
| update |
Optional |
If false will always return data, else will return no
data message if no change since submitted time |
| gmtupdatetime |
Required if update=true |
If update=true must put in the time of the last update.
Can use the top field timestamp="2018-06-20T08:46:51" to get the
last check time and then this feature can be used to only get
data when a change has occurred. |
| format |
Required |
The type of format. The value could be xml or csv. (See 'formats' action)
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Example :
enprompt.netareports.com/dataService?username=xxx&password=yyy&format=xml&action=data&chart=deratedmargin&update=false
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