REPORT Hornsea Two Offshore Wind Farm Order 2016 – Onshore Substation Site (ONSS) Non-Material Amendment Consultation and Publication Strategy Prepared David Morgan (XDMOR), 25 September 2017 Checked Amy Stirling (S&W) 27 September 2017 Accepted Natasha Litten (NATLI) 27 September 2017 Approved Doc. no. 2916960 Table of Contents Doc. no. 2916960 A. Hornsea Project Two Offshore Wind Farm ................................................ 3 (ver. no. 2916960A) B. Onshore substation site ............................................................................. 3 C. Consented parameters for Works No 8A & 8B .......................................... 4 D. Required Changes to Requirement 2(24) .................................................. 4 E. Possible Impacts of the Proposed Change ................................................ 4 F. Consultation Proposal ................................................................................ 6 G. Publication Proposal................................................................................... 7 H. References ................................................................................................. 8 HOW02 – ONSS Non-Material Amendment Consultation and Publication Doc. no. 2916960 Strategy (ver. no. 2916960A) A. Hornsea Project Two Offshore Wind Farm 1. Project Two is the second project to be developed in the Hornsea Zone, with a total generation capacity of up to 1,800 MW. The Hornsea Two Offshore Wind Farm Order 2016 (SI 2016 No. 844 as amended by SI 2016 No. 1104) (the “Order”) was granted on the 7th of September 2015. Optimus Wind Limited and Breesea Limited are the named undertakers in the Order and are hereinafter together referred to as the “Applicant”. DONG Energy Wind Power A/S is the ultimate owner of Optimus Wind Limited and Breesea Limited. Project Two received a Contract for Difference from the Department of Business, Energy, Industry and Strategy (BEIS) on the 11th of September 2017 for 1,386 MW. 2. The Applicant intends to make an application for a non-material amendment to the Order (the “Application”) to the Secretary of State. The purpose of this document is to seek the consent of the Secretary of State to a reduced list of consultees in respect of the Application and to confirm agreement to the proposed publication of the Application. 3. The document also outlines the change sought to the Order, which is a change to paragraph 2(24) of Part 3 (Requirements) of Schedule 1 (Authorised project) to increase the combined total area of the site of Works No. 8A and Works No. 8B (to bring the permitted area in line with the total combined area shown on the certified plans), and sets out the need for that change. B. Onshore substation site 1. The onshore infrastructure required for the project includes onshore export cables and either an onshore HVDC or HVAC substation depending on which technology is selected. 2. If the HVDC export option is used, an onshore HVDC converter substation will be required to allow Project Two to be connected to the National Grid. The HVDC converter substation is required to convert HVDC electricity back into HVAC suitable for connection to the grid. The footprint and layout of the substation is determined in part by the equipment, connections, safety clearances and access required for components. The HVDC converter substation will incorporate up to two approximately 900 MW or one up to 1,800 MW Voltage Source Converter (VSC) to convert the potential maximum ± 600 kV HVDC to 400kV HVAC. HVDC and HVAC switchgear will be provided to control circuits and allow safe working access. 3. If the HVAC export option is used, an onshore HVAC substation will be required to allow Project Two to be connected to the National Grid. The onshore HVAC substation will allow transformation of the voltage to the required transmission system level and will provide reactive power compensation and filtering equipment to ensure that the wind farm complies with the technical requirements to connect to the National Grid. This equipment will include up to eight main onshore transformers, 400 kV and export cable transmission switchgear, harmonic filtering equipment, shunt and dynamic reactors, autotransformers, lightning and transient protection equipment, and other auxiliary equipment. Page 3/19 HOW02 – ONSS Non-Material Amendment Consultation and Publication Doc. no. 2916960 Strategy (ver. no. 2916960A) C. Consented parameters for Works No 8A & 8B 1. The Order imposes certain restrictions on the design parameters for the onshore substation site in paragraphs 2(23) and 2(24) of Part 3 (Requirements) of Schedule 1 (Authorised project) as follows: (23) No main building forming part of Work No. 8A or 8B may— (a) where the mode of transmission is HVDC, exceed— (i) 40 metres in height; (ii) 69.5 metres in width; (iii) 135 metres in length; or (b) where the mode of transmission is HVAC, exceed— (i) 15 metres in height; (ii) 18.5 metres in width; (iii) 82.5 metres in length. (24) The combined total area of the site of Work Nos. 8A and 8B must not exceed 35,672 square metres, excluding any area of land required for landscaping and mitigation. D. Required Changes to Requirement 2(24) 1. Subsequent to the Order being granted it has been assessed that the permitted area of Works No 8A & 8B (see sheet 27 of version 2 of the Works Plans Onshore) needs to be revised in order to safely accommodate the required infrastructure for the onshore substation. This does not require an increase to the physical size of the buildings or plant within Works No 8A & 8B but does require an increase to the overall developable area occupied by Works No 8A & 8B (the additional space mainly being occupied by gravel). Works No. 8A & 8B will still be located fully within the area shown on Sheet 27 of the certified Works Plans. The only change to the Order required therefore is an amendment to the area specified in paragraph 2(24) of Part 3 (Requirements) of Schedule 1 (Authorised project). Table 4.1 details the consented and the new required wording for Requirement 2(24). Table 4.1: Consented and required design envelope for Works No 8A & 8B Works No 8A & 8B: Current envelope The combined total area of the site of Work Nos. 8A and 8B must not exceed 35,672 square metres, excluding any area of land required for landscaping and mitigation. Works No 8A & 8B: Required envelope The combined total area of the site of Work Nos. 8A and 8B must not exceed 49,326 square metres, excluding any area of land required for landscaping and mitigation. E. Possible Impacts of the Proposed Change 1. As noted above the overall area which can be developed inside Works 8A & 8B is restricted by Requirement 2(24) to 35,672 square metres (excluding any area of land required for landscaping and mitigation). Page 4/19 HOW02 – ONSS Non-Material Amendment Consultation and Publication Doc. no. 2916960 Strategy (ver. no. 2916960A) 2. The area referenced in the requirement was the area thought to be required for physical development at the time. It was taken into account, to some extent, as a parameter in the flood risk assessment in the original Environmental Statement. That was the rationale for including it as a maximum parameter in a Requirement during the Examination into the original Development Consent Order application. It is important to note that the 35,672 square metres figure in Requirement 2(24) was derived from the area understood by engineers at that time to be the area required for the substation development. In other words, it was driven by engineering input to the project description rather than any assessment of a maximum acceptable environmental parameter. 3. However more detailed design work has established that a larger overall working area for works 8A & 8B is required (as explained in section D above). 4. The Applicant and its environmental consultants have considered whether amending the figure in Requirement 2(24) from 35,672 square metres to 49,326 square metres would alter any of the conclusions in the Environmental Statement. 5. Each Environmental Statement chapter has been considered. In most instances it was very obvious that the parameter was not relevant to the original assessment and that the proposed change would have no effect. 6. Three topics required slightly closer consideration: a. Traffic and transport - it was considered whether the amended working footprint area necessitated the transportation of more materials and thereby amended vehicle movement assumptions in the Environmental Statement. This is not the case. The development proposed with the revised footprint figure in Requirement 2(24) can be delivered inside of the traffic and transport assessment envelope. b. Landscape and visual – Requirement 2(24) does not specify a particular location within which works 8A & 8B must be located, it simply restricts the overall area which these works can occupy. The change proposed does not result in an increase in the size or quantity of main buildings or plant. Nor does it alter the worst-case assumptions in terms of the locations of these buildings or plant. The amendment proposed would allow for greater separation and working area but it is not considered that this would have any material effect on the assessed landscape or visual impacts of works 8A & 8B. c. Flood risk and drainage - as noted above the “35,672 square metres” parameter was considered as part of the original flood risk assessment. In particular, this area was assessed as being an entirely impermeable surface inside of the limits of deviation of Works 8A & 8B shown on Sheet 27 of the Works Plans. This assumption was used as part of the flood risk assessment to demonstrate that even with the development it was still possible (with mitigation) to maintain greenfield volumes and rates of site run off. This conclusion requires to be further tested prior to commencement of development of the substation (once all detailed plans are available) as part of the requirement to have a detailed surface water drainage scheme approved by the local planning authority (requirement 13).