Galloper OFTO
OperationalOffshore GridGB353 MW132 kV45.85 km2017
Basic information
9 fieldsAlso Known As
Galloper offshore transmission system · Galloper OFTO · Diamond Transmission Partners Galloper OFTO · Diamond Transmission Partners Galloper Limited · DTPG · Galloper TR5 OFTO
Status
operational
Capacity
353 MW
Project Company
Type
offshore grid
Transmission Model
Developer Build & Transfer
Expected Life
20 years
Supply Chain (10)
Project Timeline (28)
26 Feb 2020Stake Transaction
On 26 February 2020, Diamond Transmission Partners signed an agreement with Galloper Wind Farm Ltd to purchase the Galloper offshore wind farm’s transmission assets under the UK OFTO regime, including the offshore substation, two subsea export cables and the onshore substation, transferring ownership of the Galloper OFTO asset package from the generator to the independent transmission owner.
Diamond Transmission Partners acquired from Galloper Wind Farm Ltd (100%)
Nov 2018Revenue Secured
In November 2018, following Ofgem’s Tender Round 5 competitive OFTO process, Diamond Transmission Partners (a 50:50 partnership between Diamond Transmission Corporation, a Mitsubishi Corporation subsidiary, and HICL Infrastructure plc) was selected as preferred bidder for the Galloper offshore transmission licence, securing the right to earn regulated transmission revenue from the Galloper OFTO assets. These assets comprise the offshore substation platform, two subsea export cables, and the onshore substation and associated connections to National Grid’s Leiston 132 kV substation, with an OFTO Initial Transfer Value of £329.1 million. The preferred bidder status marked the effective securing of the OFTO project’s long‑term regulated revenue stream ahead of contractual asset transfer completion.
Mar 2018Commercial Operations Full Power
The Galloper offshore wind farm transmission system was fully commissioned in March 2018. All 56 Siemens Gamesa 6.3 MW turbines were installed and commissioned by March 2018, with the offshore transmission assets including two export cables and the offshore substation enabling full power export to the onshore grid in Suffolk.
13 Feb 2018Ownership Other
Ofgem’s cost review documentation records that the Galloper Offshore Wind Farm, whose developer Galloper Wind Farm Limited also developed the associated transmission assets prior to OFTO divestment, was owned by a consortium including Innogy Renewables UK Limited, Siemens Financial Services, Sumitomo, ESB, and a consortium managed by Green Investment Group and Macquarie Infrastructure and Real Assets; this ownership structure was set out in Ofgem’s ex-ante report dated 13 February 2018.
~Jul 2017System Testing
Commissioning of the Galloper transmission assets took place during summer 2017, with the offshore substation, two 132 kV subsea export cables, and onshore substation at Leiston undergoing system testing ahead of first power export in November 2017. Note: date is from pre-event projection (Ofgem PIM Sep 2016); no post-event source found to verify exact timing.
Nov 2017First Power
First power from the 353 MW Galloper offshore wind farm was generated in November 2017, using the project’s offshore transmission assets, which comprise an offshore substation, two subsea export cables and an onshore substation that were later agreed to be sold to Diamond Transmission Partners under the OFTO regime.
3 Aug 2017Procurement Notice
Authority: Ofgem · Licence: Shortlisting of bidders for Galloper OFTO transmission licence tender
On 3 August 2017, Ofgem announced the shortlist of three consortia, including Diamond Transmission Partners, Mari Energy Transmission, and Transmission Capital Partners, that would proceed to the Invitation to Tender stage to compete to own and operate the Galloper offshore transmission link.
May 2017Manufacturing Update
The offshore substation for the Galloper transmission system, fabricated by Heerema at its Hartlepool yard on behalf of the Alstom–Petrofac consortium, was completed in early May 2017, marking the manufacturing and assembly completion of the platform prior to offshore installation.
May 2017Cable Installation Complete
By early May 2017, installation of the Galloper OFTO’s two export cable circuits had been completed, with the second 132 kV subsea export cable installed to connect the offshore substation to the onshore transition joint bays and onward to the new onshore substation near Leiston.
Q1 2017Construction Other
National Grid delivered the onshore connection at the Leiston 132 kV substation for the Galloper project in the first quarter of 2017, completing the physical onshore grid connection works ahead of transmission asset commissioning. The project achieved first power in November 2017, confirming these works were completed. Note: date is from pre-event projection (Ofgem PIM Sep 2016); no post-event source found to verify exact timing.