• Created by: ellieedf
  • Created on: 14-04-20 12:21


BMSUS - Balancing Mechanism Start Up Services (& Hot Standby)

Due to the gat closure of 1 hour, NG does not have short term access to BMUs which have long NDZs, without paying the BM Offer prices for long periods of time. Start up and Hot Standby Contracts give NG access to BMUs with long NDZ's by warming units to an NDZ duration that can be used in the BM window.

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Entering a BMSUS Contract

  • NG will issue, through EDL, a warming instruction (HTS) with a Hot Standby Target Time (HSTT), by reference to the current NDZ. 
  • We are expected to begin the start-up process by bringing a BMU to a BM timescale NDZ by the HSTT, in exchange for BMSUS payments.
  • There are now three significant periods: Required data period - this contractually obliges us to submit and maintain SEL, MNZT and BO Pair 1 at levels no more expensive to grid at the time the BMSUS was entered into (the time of the BMSUS instruction). This period of time runs from the Earliest Sync time until the latest sync time plus MNZT or BOA sync time plus MNZT. NG can hold a unit on hot standby for no more than 4 hours. A change that increases the volume (SEL/MNZT) or price (BO Pair 1) will result in repayment of the BMSU payments and a deemed cancellation of the HTS.
  • Comitted Period - this is the period of time between the HSTT and the HSTT+4 hrs. A MEL>SEL must be maintained for this period to ensure all BMSUS payments are secured. Also, we cannot submit a PN during this period without sacrificing BMSUS payments.
  • PN Check Period - this is 4 hrs after a cease start-up instruction (CHS), uncless CHS is issues inside the committed period, in which case this period lasts until the end of the committed period. In this period, a PN submission would result in repayment of any warming and hot standby payments accrued.
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Reaching Hot Standby

Upon reaching the HSTT, the BMU must:

  • Re-declare its NDZ to <90 minutes - otherwise BMSUS payments have to be repaid.
  • Submit/maintain final B/O pair 1, SEL and MNZT data which is no more onerous than those submitted at the point of NG comitting to the BMSUS.

Once the HSTT has been achieved (the unit is warmed), then BMSUS payments will cease and hot standby payments will begin to accrue until the unit is no longer in a Hot Standby status. If a BOA is recieved to offer the unit on, BOD rates will apply. No payments are accrued for the time between receipt of the BOA and sync.

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Hot Standby

The BMU shall maintain Hot Standby status until either:

  • The issue of a Cease Hot Standby instruction (CHS) by NG
  • The expiry of the maximum hot standby period (4 hrs from the HSTT)
  • The reduction of BMU MEL to zero
  • The unit syns - NG has the option but not obligation to offer the unit on through the BM.
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NG Cancel BMSU

If NG issue a CHS (cease hot standby) instruction before HSTT is reached, then the BMU is not allowed to continue warming in readiness for sync. However, "PN Check Period" (of 4 hrs) is entered, throughout which is BMU must maintain a PN of 0. If not the BMSUS payments accrued will be repaid.

The BMU is also required to review its NDZ and reduce it to a realistic level, based on the amount of warming that has taken place.

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Opting or Failing to Provide Service

BMSUS repayments may be due if:

  • BMU syncs on a PN between the BMSU time and the end of the committed period.
  • During the committed period, the MEL drops below the SEL priot to HSTT.
  • generator fails to maintain the time it takes to sync
  • generator fails to maintain the SEL or MNZT for the duration of the "required data period"
  • generator fails to submit a BO pair on or before the HSTT.

Hot Standby payments will not be made if:

  • BMU syncs on a PN during the committed period
  • During the hot standby period the time it takes to sync is not maintained
  • The SEL or MNZT are not maintained during the committed period
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