ISG117/04 Meeting name Imbalance Settlement Group (ISG) Date of meeting 26 October 2010 Paper title Arecleoch Non-Standard BM Unit Application Purpose of paper For Decision Synopsis This Paper summarises the responses received from ScottishPower Renewables (UK) Ltd and the Transmission Company to the ISG’s questions following the non- standard BM Unit application for Arecleoch Wind Farm presented at the ISG116 meeting on 28 September 2010. 1 Introduction 1.1 At the ISG116 meeting on 28 September 2010, the ISG116/02 paper sought the ISG’s approval for a non-standard BM Unit application made by ScottishPower Renewables (UK) Ltd (Party ID SPCRE01) for Arecleoch Wind Farm. The ISG deferred a decision on this application and requested further information from the Party and the Transmission Company. 1.2 This Paper summarises the responses received to the ISG’s request for further information. 2 Summary of the Application – ISG116/02 2.1 The site at Arecleoch connects to the main Transmission System through a single connection point. However the asset ownership lies at the two 33kV metering circuit breakers which are connected to the Transmission System via two 33/132kV transformers. 2.2 The Grid Code definition of a Power Park Module determines the point of connection to the Transmission System to be the point at which the Transmission Network Owner takes ownership of the assets. Therefore if we were to apply the standard BM Unit configurations, Arecleoch Wind Farm would consist of two Power Park Module BM Units. 2.3 The Party states that two BM Units would not enable it to efficiently meet the requirement in Section K3.1.2 for a BM Unit to be “capable of being controlled independently”. This is because more effort would be required by both the Party and the Transmission Company to issue and process instructions and Physical Notifications and to manage Settlement activities if two BM Units were registered. Therefore its opinion is that one BM Unit is the smallest possible configuration which will satisfy all the other configuration criteria specified in Section K3.1.2. 2.4 The Transmission Company have said they support this application. 2.5 The Party’s application letter (Attachment A) and a Line Diagram of the site (Attachment B) have been attached to this paper. 3 Responses received providing further information 3.1 After hearing the original application, the ISG asked for further information before making a decision. They asked that the Party provide more information on why it thinks the site cannot be independently controlled. They also asked for a fuller explanation from the Transmission Company on their reasons for supporting this application. Arecleoch Non-Standard BM Unit Application v.1.0 18 October 2010 Page 1 of 3 © ELEXON Limited 2010 ISG117/04 3.2 The full responses received from the Party and the Transmission Company are attached to this Paper (Attachment C). 3.3 The Party have highlighted the following points in their response: Despite the actual connection points being at 33kV, there is only a single entry point into the Transmission System at 132kV. They also say that although there is more than one connection/metering point, there is a single control system that governs the output for the whole Wind Farm. In relation to the provision of either mandatory or commercial ancillary services, such as frequency response or reactive power capabilities or voltage control, the requirement is for the entire Wind Farm to respond as one. When these services are provided they do so from a single point of entry at 132kV. The reactive power requirements for Grid Code compliance also have to be met at the High Voltage side of the transformers, which is the common point of entry. Any additional equipment procured for this function has to take cognisance of the losses with the TSO grid transformers. The Party is seeking acceptance of an arrangement which has been deemed acceptable previously, and therefore they would suggest that the case that they are seeking to make has already been proven in the past. Please see Section 3.5 for more details. 3.4 The full response from the Transmission Company can be found in Attachment C. They supported the original application because the System Operator does not need the ability to change the flows on an individual BM Unit basis in this case. They have also stated that, while they can provide a rationale for there being a single BM Unit, they are not wedded to this decision and can see some benefit in there being two BM Units. The Transmission Company have stated they left their response open as they will support the decision which the ISG reach. 3.5 Previous applications of this nature from Scottish Power have been heard by ISG. A similar application was made for Blacklaw Wind Farm in January 2005 (ISG48/15), requesting a single BM Unit for a configuration similar to Arecleoch. An application made for Whitelee Wind Farm in October 2007 (ISG81/03) also requested a single BM Unit where there were multiple connections to the Transmission System. The ISG approved both these applications. 4 Determination 4.1 The ISG is requested to consider whether the BM Unit configuration proposed by the applicant better satisfies the criteria set out in Section K3.1.2 of the Code than the “standard” BM Unit configurations which would otherwise apply. 5 Recommendation 5.1 We invite you to APPROVE the proposed non-standard BM Unit configuration for Arecleoch Wind Farm. David Kemp ELEXON Settlement Analyst Tel: 020 7380 4303 Arecleoch Non-Standard BM Unit Application v.1.0 18 October 2010 Page 2 of 3 © ELEXON Limited 2010 ISG117/04 List of Attachments: Attachment A – Arecleoch Non-Standard BM Unit Application Letter Attachment B – 33kV Schematic Single Line Diagram for Arecleoch Attachment C – Responses received from the Party and Transmission Company Arecleoch Non-Standard BM Unit Application v.1.0 18 October 2010 Page 3 of 3 © ELEXON Limited 2010 ISG117/04 - Attachment A Date: 25/08/10 David Kemp Elexon Limited 4th Floor 350 Euston Road London NW1 3AW Dear Mr Kemp APPLICATION FOR NON-STANDARD BM UNIT FOR: ARECLEOCH WINDFARM, BENTS FARM, BARRHILL, SOUTH AYRSHIRE, KA26 0PZ I refer to the above wind farm, which is being developed by ScottishPower Renewables (UK) Ltd. Arecleoch windfarm will be connected to the 132kV transmission system of Scottish Power Energy Networks Limited at Arecleoch substation. It is planned that the windfarm will be energised at the end of October 2010 and first export is planned for thereafter. This letter and the attached 33kV Schematic Single Line Diagram is provided as supporting information in response to recent discussions with Elexon regarding the site and our and our intention to apply for a non- standard BMU. The Grid Code definition of the Power Park Module determines the point of connection to the transmission network to be the point at which the Transmission Network Owner takes ownership of the assets. Although the site connects to the main 132kV transmission network through a single common connection, due to the connection configuration at Arecleoch windfarm the point of asset ownership at the Arecleoch substation is the two 33kV metering circuit breakers connected to the transmission system via two 33/132kV transformers. Under the Grid Code definition this would therefore require the registration of two BM Units for the one individual windfarm. In relation to the capacity of 120MW’s for this site and operation of the windfarm as one individual site, this number of BM Units would be in excess of that necessary for a sole site and would require an additional level of support in terms of issuing and processing instructions, physical notifications, controls and settlement activity for both National Grid Electricity Transmission Ltd and ScottishPower Renewables. For this reason we do not believe the standard configuration of two BM Units enables us to independently control the Plant and Apparatus in an efficient way. We are therefore of the opinion that one BM Unit is the smallest configuration which will satisfy all the other configuration criteria specified in Section K3.1.2 of the Code. It is therefore our request that the Arecleoch windfarm should instead be considered as a single non-standard BM Unit. This would present a more realistic level of support for a site of this size and configuration. If the panel should require any further information to assist in assessing this application, please do not hesitate to contact me. Yours Sincerely Craig Howarth Scottish Power Renewables ScottishPower Renewables UK Ltd, 3rd Floor New Building, Cathcart Business Park, Spean Street, Glasgow, G44 4BE Telephone 0141 568 2000 ISG117/04 - Attachment C Response received from the Transmission Company David You are right, the reply was intentionally left ambiguous. I can provide a rationale for why the generator could only have one BMU; the main rationale is that the connection agreement does not allow the local transformers to be overloaded and therefore the SO would not need the ability to change the flows on the an individual BMU basis. However, I am not wedded to this decision and can see some benefit in there being two BMUs. My ambiguity was mainly associated with the fact that I could present the issue to the ISG and let them decide. Regards Malcolm Arthur Senior Commercial Analyst Regulatory Frameworks National Grid Work: 01926 654909 (474 4909) Mobile: 07789 942691 From: BM Unit Sent: Friday, October 01, 2010 1:57 PM To: Arthur, Malcolm; Harrison, Peter Cc: Mullen, Paul J; Smith, Ben; BM Unit Subject: RE: Non-Standard Configurations for Arecleoch and Mark Hill Hi Malcolm, Thanks for this.