London Array


It was in July 1887 that Scottish academic James Blyth installed the world’s first electricity-generating wind turbine. Although at the time considered uneconomical in the UK, electricity generating wind turbines proved to be far more cost effective in countries with widely scattered populations, a fact that saw American inventor Charles F Brush follow up Blyth’s work some months later by building the first automatically operated wind turbine for electricity production in Cleveland, Ohio.

Fast forward to the 21st Century and the world finds itself in a situation where rising concerns over energy security, global warming, and eventual fossil fuel depletion have led to an expansion of interest in all available forms of renewable energy, including wind power. It was due to this interest that the fledgling commercial wind power industry began expanding at a robust growth rate of about 30 percent per year, driven by the ready availability of large wind resources, and falling costs due to improved technology and wind farm management.

Today, London Array is arguably the most widely known UK offshore wind farm and the largest of its kind found anywhere in the world. Following confirmation of the suitability of the area for construction of a wind farm site, the London Array project was officially born in 2001, with the Crown Estate providing the consortium of operators at the time, Shell WindEnergy Ltd, E.ON UK Renewables and DONG Energy, a 50 year lease for the site and cable route to shore, which was entered into in 2004.

Planning consent for the project’s 1GW offshore wind farm was granted in 2006, with permission granted for the onshore works following in 2007. Work on Phase One started in July 2009 when building commenced on the onshore substation at Cleve Hill in Kent, whereas offshore construction started in March 2011 when the first foundation was installed. The first turbine was installed in January 2012, with first power achieved in October that year and the final turbine installed in December 2012.

“We reached the key milestone of having the 175th and final turbine commissioned on 6 April, 2013,” states Project Director, Richard Rigg, “an event which effectively marked the culmination of the installation of the 630MW wind farm. From that point on the complete wind farm has been generating and earning revenue.”

Such is the sheer scale of London Array that it is estimated that its 175 turbines will be capable of generating enough energy to power nearly half a million homes and reduce harmful CO2 emissions by over 900,000 tonnes a year.

“When this project was first conceived,” Rigg continues, “I think it is fair to say that it was felt by many that an undertaking of this size could simply not be carried out.” Indeed at the time there wasn’t even any legislation in place that allowed for the construction of a project the size of London Array.

Nevertheless, it is with a great sense of pride that Rigg can declare that despite the considerable challenges that the consortium has encountered in the last decade or so, London Array looks set to deliver on the promises it made back at the time of its conception.

Said challenges include overcoming the obstacles that presented themselves due to the location of the project in the outer Thames Estuary. Here the water depth can range at lowest atmospheric tide from 25 metres right down to minus one metre, meaning that at various points some areas of the site actually dry out.

“As you can imagine,” Rigg highlights, “when you have to get a large vessel in to install components weighing around 650 tonnes you have to ensure that you get it in at high tide, jack it up and then await the return of higher water levels before getting it back out again. All of this adds an extra degree of complexity to the work you are doing.”

In addition to these logistical difficulties the project has been hampered by several extensive periods of bad weather, worse than that anticipated and factored in by the consortium. Regardless of these setbacks the project ended up having what Rigg describes as a remarkable year in 2012. “By the end of December 2012 we had installed in the space of ten months all bar a few array cables, three of the four export cables, and 90 of the 177 foundations. That means that we finished the year installing the last turbine within a few weeks of the date we actually set back in May 2009, which I think is a fantastic achievement.”

The consortium, which now consists of DONG Energy, E.ON and Masdar, is very keen to stress that it sees London Array as being the first real industrial scale offshore wind farm, with its success being a precursor to the next round of wind farms due to appear off the coasts of the UK.

Where it also hopes to see the project being labelled an inspiration for future developments is in its efforts towards benefiting the environment and the local communities who reside around the site. It has long been the aim of the consortium to see London Array playing a key role in helping the UK to meet various renewable energy targets. By reducing carbon emissions by more than 900,000 tonnes a year the project will be playing a critical role in helping to tackle the effects of climate change and global warming, this providing significant, long term environmental benefits.

“It is important to recognise that in addition to London Array there are a number of other large offshore wind farms that really are contributing to this shared goal,” Rigg explains. “The more this happens, the sooner people will recognise the scale of the contributions these projects are making. In turn they will hopefully then realise that these wind farms can generate industrial amounts of electricity and play an important role in the energy mix of the future.”

While the wind turbines that make up London Array stand 20 kilometres out to sea, the project has still had a big impact of the onshore communities in the Cleve Hill and Ramsgate areas, a fact that has not been lost on the consortium. In the early days of the project it faced natural opposition to its plans for building its Cleve Hill substation. Respecting this opposition the consortium embarked on a programme of engagement, working hard to involve local people and keeping communities informed about the progress of the project at all times.

“The relationship we have built up with the local villages of Graveney and Goodnestone is nothing short of excellent and have already proven to be mutually beneficial for all concerned,” Rigg enthuses. Examples of some of the positive results to come from these relationships include London Array’s support of a university bursary scheme, the creation of a community fund managed by an independent trust, its donations to various wildlife funds and the annual donations made to three local schools.

Equal effort has been made by the consortium in Ramsgate where it has endeavoured, wherever possible, to employ local people to its construction and operations and maintenance teams, and to source from local suppliers, not only during the construction phase of the project but for all manner of activities related to the project, from hotels and taxis to bringing in a local company to supply the Cleve Hill substation with high speed internet access.

Now that London Array is into its operational phase the focus of the consortium turns to ensuring that it works as effectively and efficiently as possible. In doing so it is expected to produce some hugely important performance figures that its owners hope can then be used to demonstrate that wind farms have indeed become serious players in terms of today’s energy mix.

Looking ahead to the future, Rigg points out that while what has already been achieved is hugely significant, there is more work to be done if mankind is to get the most out of offshore wind power. “The aim for the industry as a whole is to bring down the costs associated with offshore wind and improve the overall reliability of wind power generation. While there is still much to be done if we are to reap the full rewards that wind power has to offer there can be no doubt that the lessons learnt from London Array will prove invaluable for those behind the creation of the next generation of wind farms.”

www.londonarray.com

Written by Will Daynes, research by Louisa Adcock