Tide Turns With More Offshore on Horizon

Sep 28 - Scotsman, The

Of all the renewable energy sources, offshore wind has the capacity to make the largest contribution to clean energy. The simple fact is that it is much easier to get planning permission for a large number of wind turbines for a site that is a long way from shore than it is to get permission to festoon a hillside with dozens of the contraptions.

The fact that in April this year, Scottish Power managed to get approval from the Scottish Executive to build Scotland's largest onshore wind farm on a stretch of moorland to the south of Glasgow should be regarded as an exception the rule.

The idea of gaining 322 megawatts of "green" output by 2009 - enough to light up residential Glasgow - was exciting enough to the Executive to cause it to fend off public concerns over the Whitelees project's impact on the landscape. Even so, the approval process took five years to get through the public consultation exercise. Other large-scale onshore projects are likely to find the going almost impossible.

With onshore projects difficult to scale up, offshore is set to become more important over the next five to ten years. The British Wind Energy Association (BWEA), for example, has calculated that, taken as a whole, the UK's potential offshore resource amounts to three times the UK's annual electricity consumption.

New as it sounds, offshore wind already has an active history behind it. It is now six years since the UK's first offshore wind farm, a two-turbine affair, was commissioned near Blyth Harbour in Northumberland. The second round of the government's licensing of offshore acreage to developers, through the Crown Estates Office, took place in 2003 and, while there have been worrying delays to round-one projects - never mind round-two projects - things are progressing, albeit slowly.

According to the BWEA, there are now 13 projects that have received consent, comprising a total of almost 1,200MW of output. Three of these are round-one projects that are already operational and generating 210MW between them. These three are North Hoyle, off the coast of North Wales; Scroby Sands, off the coast of Great Yarmouth and the newly- commissioned Kentish Flats, off Whitstable in Kent.

The BWEA's best-practice recommendations are for offshore wind farms to be built no closer than five miles from shore. Even on a clear day the turbines are barely visible at that range. Round-one sites were supposed to be at least three miles from shore. Some of the proposed round-two sites are a good deal further from shore than five miles.

While environmental impact assessments and the implications for fishing and shipping have to be sorted out with these projects, at least the "not in my backyard" factor becomes much less significant.

The first major offshore project to get going, setting aside Blyth Harbour two-turbine test, was npower's North Hoyle. Built in 2003, the project now produces enough green energy each year to meet the needs of some 40,000 homes.

The North Hoyle offshore wind farm is located almost five miles off the North Wales coast, between Rhyl and Prestatyn. As is usual with round-one projects, it consists of 30 wind turbines, each rated at 2MW. The size and output of the turbines on offshore farms is expected to rise to 3MW for later projects while turbines have the potential to grow to 5MW and beyond over the next few years. In fact, the Talisman/Scottish and Southern Energy Beatrice project (see story on the right) is already being commissioned with 5MW turbines.

One of the interesting features of the npower project is that the company worked together with Greenpeace to design a green energy offering called "npower juice", to domestic npower customers.

While it is not feasible to differentiate between green electricity and coal- generated electricity once it is in the grid, npower's offering ensures that for every unit of energy an npower juice customer uses, the company feeds the same amount into the electricity network from a renewable energy source, primarily from North Hoyle. Turbine manufacturer Vestas provided the turbines for North Hoyle and also for the E.ON project, Scroby Sands, which was built in 2003 on a sand bank three miles off the Great Yarmouth coast.

The Kentish Flats offshore wind farm, owned by Elsam, began commercial operation in December 2005. Located in the Thames Estuary, it too comprises 30 Vestas wind turbines but these have a rated capacity of 3MW. This plant now holds two records; it is the largest wind farm to be installed in the UK so far and uses the largest turbines yet installed. It is expected to produce 285MW of electricity every year, enough to power 100,000 homes.

Centrica's Lynn and Inner Dowsing round-one projects have been stalled for some time (see story below). As is the case with several other developers, Centrica plans to take these two adjacent sites located 3.2 miles off the coast of Skegness and Ingoldmells, and combine them into a single 60-turbine site.

A number of round-two projects have now received consent and are in various stages of planning and construction. According to Dr Gordon Edge, director of offshore at the BWEA, there is still only about 700MW of offshore wind power installed world wide (with 210MW in the UK, as we have seen). This compares rather poorly to the 52 gigawatts (GW) of onshore wind generation capacity installed globally to date.

Edge points out that if one takes the total capacity of all the round-one consented offshore wind projects in the UK, this amounts to 1GW - substantially more, in other words, than the global installed figure. The UK is currently second only to Denmark in terms of installed offshore wind capacity, and is set to overtake Denmark as the round-one projects are completed over the next few years.

As and when a number of the much larger scale round-two projects, some of which are already consented, are built, hopefully before 2010, the UK will have global leadership in this field.