A Large, Multi-phase Wind Farm
The Clyde wind farm, operated by SSE, includes an existing, operating part and a consented extension (due to start operating in 2017).
The existing wind farm comprises of 152 Siemens 2.3 MW turbines, giving a total installed capacity of 349.6 MW. The wind farm also has 13 anemometer masts to measure wind performance.
In documents related to a sale of part of the wind farm in March 2016 (detailed below), net load factor was reported as 33.0%.
The farm is split into three sections over a total area of 47 square km. The south section has 56 wind turbines (129 MW), the north section has 47 (108 MW), and the central section 49 (113 MW). Turbines are erected on reinforced concrete gravity bases with a hub height of 80m and a blade diameter of approximately 90m.
Approximately 105km of roads were constructed to enable access to the furthest reaches of the site. Associated infrastructure also included two substations to transmit power into the national grid, one operations building and a new radar installation in Cumbernauld.
The total estimated investment was £600m.
In addition to electricity sales, all three sections of the farm are ROC* accredited from their dates of completion (between July 2011 and August 2012 – see below), receiving 1 ROC per MWh generated. At the time of writing, a ROC has a value of about £45.
*In the UK, A ROC is a Renewable Obligation Certificate, issued to operators of accredited renewable generating stations for the electricity they generate. Operators can trade ROCs with other parties. ROCs are used by suppliers to demonstrate that they have met their renewable obligation (RO); a government-mandated target. After coming into existence in 2002, it used to be one of the main support mechanisms for large-scale renewable electricity projects.
The RO scheme closed to all new generating capacity on 31 March 2017, replaced by a scheme called “Contracts for Difference” (CfD); an auction-based system based on a fixed “strike price” (more akin to a fixed-tariff/FiT type system, rather than a floating-value certificate-trading system). For existing generators, the RO scheme will continue to run until 2037 – so ROCs will continue to have a value.
Consent for Clyde wind farm was granted by Scottish Ministers in July 2008. Construction commenced in April 2009 and was completed in 2011. The first turbine was connected to the national grid in June 2011.
The 130MW south section came into operation in July 2011. The central and north sections have been operational since August 2012.
Wind Farm Extension timeline
SSE submitted a proposal for a 57-turbine, 171MW extension to Clyde Wind Farm to Scottish Ministers in October 2011.
In August 2012 this proposal was amended to reduce the number of turbines to 54. Nine turbines were moved, the tip height of ten turbines was reduced, one met mast was moved and changes were made to cabling plans – all in response to landscape and visual concerns expressed by stakeholders during the planning consultation process.
The 54 turbine extension to Clyde was granted consent in 2014.
The new turbines are Siemens direct-drive 3.2 MW turbines, with a 101m rotor diameter. They combine to give an extension capacity of 172.8 MW; and hence a total wind farm capacity of 522.4 MW.
Site preparation started in May 2015, construction commenced in July 2015, with turbine delivery and installation due to begin in June 2016. Completion of the project is expected June 2017.
The extension has an expected net load factor of 37.8% and will receive 0.9 ROCs per MWh generated. It’s worth noting how, in essentially the same wind resource area, the net load factor is expected to be nearly 5% higher in the extension than in the original wind farm – a good example of how increasing performance, not just reducing costs, is improving the economics of wind power generation.
19 full-time SSE staff and 39 Siemens staff are based across the existing site with additional jobs created off-site to facilitate operations and maintenance.
In addition to direct employment benefits, the Clyde wind farm fund (CWFF) was established for the benefit of local communities. The fund can be used to secure investment, create employment, secure sustainable development or implement training.
As of March 2017, SSE stated that these community funds have so far awarded over £3.5m towards local projects and initiatives since commencing in 2011. They estimate the funds to be worth around £20m over the lifetime of the wind farm.
With specific reference to the Clyde extension, SSE suggest that it could contribute £120m to the Scottish economy during the construction phase and, on average, support around 500 jobs through supply chain contracts.
SSE cashes in some of its investment
In March 2016, after four years of operation, SSE decided to extract some of the value of its investment by selling 49.9% of the wind farm to Greencoat UK Wind Plc (UKW) and GMPF & LPFA Infrastructure LLP (GLIL) for a headline consideration of £355 million.
UKW is a renewable infrastructure fund, solely and fully invested in eighteen operating UK wind farms. GLIL is a joint venture between the Greater Manchester Pension Fund and London Pensions Fund Authority. UKW acquired 28.2% of Clyde and GLIL acquired 21.7%. It is a good example of long-term, low-risk investment funds buying into the predictable returns of am operating, proven wind energy project.
The sale also included provision for the soon-to-be-operating extension to Clyde. When the extension is commissioned in June 2017, the equity stake jointly owned by UKW and GLIL will be diluted to 30% with SSE retaining 70%.
Within the deal was the agreement that, in addition to completing the construction of the extension, SSE will provide long term management services for the operations of the full site (existing plus extended capacity) as well as the long-term PPAs that provide a route to market for the energy generated. Siemens will provide long-term turbine O&M services.
The structure of the transaction implied a valuation of £2.03m/MW for the existing Clyde wind farm and £2.70m/MW for the Clyde extension.
[last update April 2017]