15.0

<div data-id="a-guide-to-<u class='defined-term'>electricity</u>-imbalance-pricing-in-great-britain" style="text-align:left">A guide to <u class='defined-term'>electricity</u> imbalance pricing in <u class='defined-term'>Great Britain</u></div>

<div data-id="imbalance-prices" style="text-align:left">Imbalance prices</div>

<div data-id="imbalance-charges" style="text-align:left">Imbalance charges</div>

<div data-id="1" style="margin-left:0.39in;text-align:left;text-indent:-0.39in">1. Summary</div>

<div data-id="the-basic-starting-point" style="text-align:left">The basic starting point</div>

<html><head></head><body><div data-id="what-is-the-transmission-system" style="text-align:left">What is the Transmission <u class="defined-term">System</u>?</div></body></html>

<html><head></head><body><div data-id="why-does-the-transmission-system-need-to-be-balanced" style="text-align:left">Why does the Transmission <u class="defined-term">System</u> need to be balanced?</div></body></html>

<div data-id="physical-notifications-contract-notifications-and-gate-closure" style="text-align:left"><u class='defined-term'>Physical Notification</u>s, Contract Notifications and <u class='defined-term'>Gate Closure</u></div>

<html><head></head><body><div data-id="transmission-system-net-imbalance" style="text-align:left">Transmission <u class="defined-term">System</u> net imbalance</div></body></html>

<html><head></head><body><div data-id="how-does-the-system-operator-balance-the-transmission-system" style="text-align:left">How does the <u class="defined-term">System</u> Operator balance the Transmission <u class="defined-term">System</u>?</div></body></html>

<html><head></head><body><div data-id="timing-of-the-balancing-mechanism-terre-and-bsad" style="text-align:left">Timing of the Balancing Mechanism, TERRE and <u class="defined-term">BSAD</u></div></body></html>

<div data-id="ancillary-services-and-commercial-agreements" style="text-align:left">Ancillary Services and Commercial agreements</div>

<div data-id="the-balancing-mechanism" style="text-align:left">The Balancing Mechanism</div>

<html><head></head><body><div data-id="bid-offer-pairs-for-a-bm-unit" style="text-align:left"><u class="defined-term">Bid-Offer Pair</u>s for a <u class="defined-term">BM Unit</u></div></body></html>

<div data-id="bid-offer-acceptances-boas" style="text-align:left">Bid <u class='defined-term'>Offer</u> <u class='defined-term'>Acceptance</u>s (BOAs)</div>

<div data-id="trans-european-replacement-reserves-exchange-terre-actions" style="text-align:left">Trans European <u class='defined-term'>Replacement Reserve</u>s Exchange (TERRE) Actions</div>

<div data-id="short-term-operating-reserve-stor" style="text-align:left"><u class='defined-term'>Short Term Operating Reserve</u> (<u class='defined-term'>STOR</u>)</div>

<div data-id="demand-control" style="text-align:left">Demand Control</div>

<html><head></head><body><div data-id="balancing-services-adjustment-data-bsad" style="text-align:left"><u class="defined-term">Balancing Services Adjustment Data</u> (<u class="defined-term">BSAD</u>)</div></body></html>

<div data-id="balancing-services-adjustment-actions" style="text-align:left"><u class='defined-term'>Balancing Services Adjustment Action</u>s</div>

<div data-id="buy-price-price-adjustment-bpasell-price-price-adjustment-spa" style="text-align:left"><u class='defined-term'>Buy Price Price Adjustment</u> (BPA)/<u class='defined-term'>Sell Price Price Adjustment</u> (SPA)</div>

<html><head></head><body><div data-id="party-imbalances" style="text-align:left"><u class="defined-term">Party</u> imbalances</div></body></html>

<div data-id="2" style="text-align:left">2. Key Concepts</div>

<div data-id="what-do-we-use-to-calculate-the-energy-imbalance-price" style="text-align:left">What do we use to calculate the energy imbalance price?</div>

<html><head></head><body><div data-id="the-bsc-systems-calculate-the-energy-imbalance-price-using-balancing-actions-accepted-by-the-so-for-that-settlement-period" style="text-align:left"><span>The <u class="defined-term">BSC <u class="defined-term">System</u>s</u> calculate the energy imbalance price using balancing actions accepted by the SO for that <u class="defined-term"><u class="defined-term">Settlement</u> Period</u>.</span></div></body></html>

<div data-id="which-balancing-actions-to-use" style="text-align:left">Which balancing actions to use?</div>

<html><head></head><body><div data-id="how-are-balancing-actions-submitted-to-the-bsc-systems" style="text-align:left">How are balancing actions submitted to the <u class="defined-term">BSC <u class="defined-term">System</u>s</u>?</div></body></html>

<div data-id="explanation" style="text-align:left">Explanation</div>

<div data-id="determining-stor-action-prices" style="text-align:left">Determining <u class='defined-term'>STOR Action Price</u>s</div>

<div data-id="null-priced-balancing-services-adjustment-actions" style="text-align:left">NULL priced <u class='defined-term'>Balancing Services Adjustment Action</u>s</div>

<div data-id="emergency-flagging" style="text-align:left">Emergency Flagging</div>

<html><head></head><body><div data-id="system-operator-flagging" style="text-align:left"><u class="defined-term">System</u> Operator Flagging</div></body></html>

<div data-id="continuous-acceptance-duration-limit-cadl-flagging" style="text-align:left"><span lang="fr-FR"><u class='defined-term'>Continuous Acceptance Duration Limit</u> (<u class='defined-term'>CADL</u>) Flagging</span></div>

<div data-id="ranked-sets" style="text-align:left"><u class='defined-term'>Ranked Set</u>s</div>

<div data-id="unranked-balancing-actions" style="text-align:left">Unranked balancing actions</div>

<div data-id="ranked-balancing-actions" style="text-align:left">Ranked balancing actions</div>

<div data-id="de-minimis-tagging" style="text-align:left">De Minimis Tagging</div>

<div data-id="arbitrage-tagging" style="text-align:left">Arbitrage Tagging</div>

<div data-id="niv-tagging" style="text-align:left">NIV Tagging</div>

<div data-id="replacement-price" style="text-align:left"><u class='defined-term'>Replacement Price</u></div>

<div data-id="par-tagging" style="text-align:left">PAR Tagging</div>

<div data-id="transmission-loss-multipliers-tlms" style="text-align:left"><u class='defined-term'>Transmission Loss Multiplier</u>s (TLMs)</div>

<div data-id="3" style="text-align:left">3. How does pricing work?</div>

<div data-id="energy-imbalance-price-calculation-processes" style="text-align:left">Energy imbalance price calculation processes</div>

<div data-id="4-1" style="text-align:left">1. Receive Balancing Actions (Includes SO-Flagging, <u class='defined-term'>CADL Flagged</u>, Emergency Flagged)</div>

<div data-id="4-2" style="text-align:left">2. Determine <u class='defined-term'>STOR</u> action price</div>

<div data-id="4-3" style="text-align:left">3. Formulate the <u class='defined-term'>Ranked Set</u>s of balancing actions</div>

<div data-id="4-4" style="text-align:left">4. Remove De Minimis and Arbitrage actions</div>

<div data-id="4-5" style="text-align:left">5. <u class='defined-term'>Class</u>ification</div>

<div data-id="4-6" style="text-align:left">6. <u class='defined-term'>Net Imbalance Volume</u> (NIV) Tagging</div>

<div data-id="4-7" style="text-align:left">7. <u class='defined-term'>Replacement Price</u></div>

<div data-id="4-8" style="text-align:left">8. <u class='defined-term'>Price Average Reference Volume</u> (PAR) Tagging</div>

<div data-id="4-9" style="text-align:left">9. <u class='defined-term'>Buy Price Price Adjustment</u> (BPA) / <u class='defined-term'>Sell Price Price Adjustment</u> (SPA)</div>

<div data-id="4-10" style="text-align:left">10. <u class='defined-term'>Transmission Loss Multiplier</u> and final energy imbalance price calculation</div>

<div data-id="4" style="text-align:left">4. Pricing calculation example</div>

<div data-id="5" style="margin-left:0.39in;text-align:left;text-indent:-0.39in">5. How does the <u class='defined-term'>Market Price</u> work?</div>

<div data-id="6" style="text-align:left">6. Imbalance charges</div>

<div data-id="settlement-reports" style="text-align:left"><span>S</span><span lang="en-GB"><b>ettlement Reports</b></span></div>

<div data-id="7" style="text-align:left">7. Imbalance pricing data</div>

<div data-id="8" style="text-align:left">8. Glossary</div>

<div data-id="dynamic-methods" style="text-align:left">Dynamic Methods</div>

<div data-id="when-is-lolp-published" style="text-align:left">When is LOLP published?</div>

<div data-id="9" style="text-align:left">9. Appendix 1 – The <u class='defined-term'>Reserve Scarcity Price</u></div>

<div data-id="10" style="text-align:left">10. Appendix 2 – Demand Control actions</div>

<div data-id="further-information" style="text-align:left">Further Information</div>

<div data-id="11" style="text-align:left">11. Appendix 3 – The BPA and SPA</div>

CONTENTS

Imbalance Pricing Guidance V15.0

Defined Terms

Cross-references