Mike Parr, Director of independent energy consultancy PWR, has developed a unique near-shore floating offshore wind farm project in the Firth of Clyde off the western coast of Scotland. Thanks to its design as a vessel at mooring, writes Parr, the farm does not require any planning permits and thanks to its low cost, it does not need subsidies. The first of these floating wind turbines will be installed this month north of Turnberry golf course. Donald Trump, owner of the golf course, will no doubt appreciate the lower regulatory burden involved in this type of project, writes Parr.
The trend with respect to off-shore wind turbines has been to site very large off-shore farms long distances out to sea. This is done for two reasons, stronger and often more reliable winds and minimisation of visual impact. However, there is an argument for having near-shore turbines in locations that benefit from the funnelling effect that estuaries often have.
In the case of the UK, locations such as the Bristol Channel and the Firth of Clyde both exhibit strong funnelling effects – further into the estuary wind speeds rise (a problem for crossings such as the two Severn bridges).
Another feature of off-shore wind projects is the relatively onerous planning application process, coupled to the fact that fees have to be paid (in the UK) for seabed use to what is prosaically called “The Crown Estate” which funnels the fees to the Queen.
However, I have found that there is one class of sea faring object that does not have to pay significant fees (in Scotland) and these are vessels at moorings. There is a fee for the mooring, but it is not significant. What is more, vessels are not subject to planning permits.
For a wind farm to fulfil these conditions, it would need to be a floating structure. Floating turbines have only recently begun to be built for deep waters, e.g. Vattenfall’s Hywind pilot project off the coast of Peterhead, Scotland, but PWR has now developed the first floating near-shore turbines.
The farm will run from north of Turnberry golf course and down past Girvan. Turbine spacing will be every kilometre and will be staggered to take into account westerly/south westerly winds
The Clyde has a relatively small tidal range (e.g. spring tide of 3.1 metres) and fairly low tidal currents typically 1 knot maximum. These conditions make it ideal for anchored/floating wind farms.
The above circumstances have led PWR to develop a 200MW project featuring 22 floating wind turbines located off the east coast of the Firth of Clyde, financed by a consortium led by Goldman Sachs in Scotland.
The turbines are next-generation Vestas machines with tip heights of 300 metres. These will be located roughly 2 km off the coast in about 20 metres of water. A Japanese company with long experience in fabricating floating structures, will supply, from a Scottish site, the platforms for the turbines. Assembly will take place in Greenock.
As part of our Corporate Social Responsibility programme, low cost power will be offered to communities and businesses visually affected by the wind turbine
Anchors will take the form of 20 tonne suction buckets (fabricated locally) which will work well in the deep sediments which are a feature of this part of the coast. These can be quickly and easily installed from small vessels. A simple flotation jacket allows a small fishing boat or similar to tow the anchor into position, controlled deflation of the jacket results in the bucket sinking onto the sea bed and a simple pump sucks out the water with water pressure driving the inverted bucket into the seabed with water pressure holding it there.
Installation will commence tomorrow, weather permitting, and those on the coast of the Clyde with binoculars or sharp eyes will see various boats installing the sea anchors. The turbines are expected to be towed into position by mid-April.
Connections, farm to shore, will take a somewhat unusual route. Each wind turbine will output around 9MW which is roughly equivalent to the size of a 33kV/11kV substation. Thus each turbine will have its own, on-shore sub-station connecting directly into the local 33kV network. This will be a very low cost way of moving power from the turbines to shore. The local 33kV network will only require modest and thus inexpensive reinforcement.
The farm will run from north of Turnberry golf course and down past Girvan. Turbine spacing will be every kilometre and will be staggered to take into account westerly/south westerly winds. Capacity factors of around 50% are expected. This coupled to the simple no-planning approach and very simple install, points to LCOEs of perhaps sub-Euro30/MWh.
Locations with coastal golf courses appear to be amongst the windiest. This suggests that golfers can look forward to more visual and aural delights in the future
As part of our Corporate Social Responsibility programme, low cost power will be offered to communities and businesses visually affected by the wind turbines. Girvan is one location where there is significant energy poverty and as such it is likely that the prospect of electricity at a significant discount to that provided by the incumbent utilities (the “big six”) will no doubt be welcomed. Furthermore, given the low cost of generation, there is neither the need nor the intention to apply for a subsidy. This is another reason why government need not get involved.
That said the Scottish administration looks on this development in a very positive way and hopes that many other locations in Scotland could be developed.
In terms of visual impact, this will not be so great – it would be that of a 3 metre tall object situated 20 metres away from an observer that was 2cms tall. There will also be the offer of free epilepsy tests for those concerned that they may be affected by the stroboscopic effect (sun behind the blades) of turbine blades almost 200 metres in diameter.
Contact with locals has so far been positive. Those in Girvan (which as noted before suffer from significant levels of energy poverty) are mostly enthusiastic about obtaining low cost electricity. Management of the Turnberry golf course have not responded to the information we have supplied to them, but staff (Bob Bruce and Rab Burns) have been positive, they thought the wind farm would look quite interesting – and would be a benefit if it helped to chase away “bloody seagulls wheeling about the sky and crapping on everybody”.
On the top of each wind turbine there will be a unique sound system capable of generating within 100 feet a sound level of 160 decibels – more than enough to deflect even those seagulls with defective hearing
The wind farm will use a rather unique way to deflect birds. Studies by the University of Glasgow have found, unsurprisingly, that birds can be both attracted and repelled by sound. Thus on the top of each wind turbine there will be a unique sound system capable of generating within 100 feet a sound level of 160 decibels – more than enough to deflect even those seagulls with defective hearing. The sound impact on the coast will be just a pleasant murmur of, for example, Scottish bagpipe music which has been found to be effective at repelling birds. In the case of Turnberry one could characterise the sound from the turbines as pleasant mood/background music for golfers as they tee-off or go for a birdy.
PWR is currently in discussion with the Scottish government concerning other locations suitable for large-scale near-shore floating wind farms on both the east and west coast. As it happens locations with coastal golf courses appear to be amongst the windiest. This suggests that golfers can look forward to more visual and aural delights in the future.