It is a quite staggering feat of engineering.
Whether you’re for or against wind farms, the 116 steel turbines of the Rampion wind farm 8-12½ miles off the Sussex coast are a remarkable sight from the beach, but they’re astonishing to see up close.
Twenty-six square miles of the English Channel are now dotted with the 140-metre tall turbines (from foot to blade tip), each roughly a third of a mile apart, and they’re the kind of construction that’s so huge you never seem to get up to them until suddenly you’re craning your neck beneath the gigantic blades, each 55 metres in length.
We took a boat trip to see them – there’s a choice of tour operators that will take you from Brighton Marina – and depending on tide and weather, they depart most days.
It took about 50 minutes, then the engine was turned off and we sat in the midst of this futuristic steel forest.
It was a calm sea that day, though raining, and the blades were barely turning. It’s a well-known fact that new wind turbines generate electricity on average 30-40% of the time, and this ‘load factor’ is taken into account when the amount of electricity they generate is calculated, which according to E.On, will be enough to supply 350,000 homes a year with electricity, reducing carbon emissions by 600,000 tonnes, it claims..
To begin with, anyway. Some reports say the capacity deteriorates as they age: professor Gordon Hughes, an economist at Edinburgh University and a former energy adviser to the World Bank, says generating power is likely to reduce by half within 15 years.
The land for Rampion has been leased from the Crown Estate, and in 25 years’ time there will be an option to extend the lease or take the turbines down and re-install them – if they last that long.
The power generated at brand new Rampion is currently meeting predictions, and is collected at the offshore substation, some 3,000 tonnes of technical equipment and cable, which is permanently based in the wind farm.
Parked next to the substation when we were there was the jack-up barge, MPI Discovery. This ships the equipment and tools and accommodates up to 140 engineers. It has six legs, which are carried above the body of the vessel until it anchors, when they are lowered to the sea bed. Once firmly planted, the body of the ship is jacked up above the waves, providing a completely stable platform from which to
balance a bridge to the substation.
C4S was told the cost of the installation, which is owned by E.On and its partners the Green Investment Group and Enbridge, a north American energy supplier, was £1.3 billion, with no government subsidy. Some estimates put the figure at twice that, but the group still has to pay back its shareholders – and thanks to the tax payer-funded Renewable Obligation Certificate (ROC) scheme that was in operation when Rampion was approved, it should bring in at least £170 million a year.
ROCs are a complicated system of compensation, whereby companies are awarded two ROC’s (worth £47.22 each, according to Ofgem, the government’s gas and electricity administrators) per Megawatt hour (MWh) generated. This means they earn just over £90 per MWh. Based on E,On’s calculations that they will generate 1,367 Gigawatt hours a year, this makes an annual income of £123 million from the tax payer.
On top of that, E.On will receive around £35 per Mwh from its customers – another £47 million a year, totalling £170 million a year.
The wind farm was installed in line with current policy to cut carbon emissions.
Josh Snape, from the Department for Business, Energy and Industrial Strategy (BEIS), says wind supplies 15 per cent of the UK’s energy.
According to the trade association Renewable UK, there are now 8,889 on- and off-shore wind turbines in the UK.
A quick envelope calculation will tell you we’d need nearly 60,000 of them to supply 100 per cent of the UK’s energy.
Of course no one is suggesting we aim for that, and there are other forms of energy – wind is just one part of the green energy mix.
But just how green is it?
The driving force behind Rampion – and all other renewable energy projects – is the fear of carbon emissions, much of which comes from the burning of coal.
Coal is needed to produce steel, and according to the World Coal Association, it takes half a tonne of coal to produce one tonne of steel.
Each steel turbine and foundation weighs an average of 1,300 tonnes. A quick couple of sums will reveal that 75,000 tonnes of coal were burned in making Rampion’s turbines – and before it was burned it had to be mined and shipped, resulting in more carbon emissions.
That’s just the coal. The steel then had to be processed, shipped and installed – using yet more fossil fuels.
The thousands of tonnes of rocks for scouring had to be dug and then shipped.
Wind turbines also need an enormous amount of rare earth for their gear boxes and generators, according to the US-based Institute of Energy Research.
Minerals like neodymium and dysprosium, for instance, are mined almost exclusively in China, IER says, in toxic conditions with scant regard for local populations.
And because of wind’s intermittency, a gas power station has to be kept running all the time – although BEIS’s Snape says modern power stations are responsive enough to be kept off until they are required.
We showed the Green Party these calculations, and they said: “When it comes to the carbon emissions at installation, the reality of any major infrastructure project is that there will be some, but once the turbines are generating electricity, that carbon will be compensated by the lack of fossil fuels involved in the process.
“On the subject of cost, the £1.3 billion cost is a consequence of the government continuously failing to provide enough subsidies for renewables.
This has made it more expensive to develop at the scale that we need for a truly low carbon future.”
Friends of the Earth spokesman Chris Todd said the charity was in principle supportive of wind farms, while aware of sensitivities.
“We had reservations and criticism over aspects of it, but E.on addressed some of the main ones,” he said. “One was the impact of the heritage coast around Seaford and Beachy Head, which is fairly remote. Originally the wind farm was quite expansive and the view would have been affected, but they moved them slightly further away.
“They set up lots of working groups and from an engagement point of view a lot of work was done, with fishing and environmental groups.”
Although there are claims – and some evidence – that turbines slaughter a lot of birds, we didn’t see any feathered corpses floating on the calm waters, and our guides said they hadn’t noticed any in all the trips they have made.
The Royal Society for the Protection of Birds had nothing to say about Rampion, but did say the importance of climate change meant it was in favour of wind farms as long as they were sited with concern for conservation.
Chairman of UKIP for Mid-Sussex Chris French opposes wind farms in their entirety, and set up a Facebook page in protest while Rampion was in its planning stages.
“From an economic point of view, if E.On didn’t receive millions of pounds of subsidy, they wouldn’t have done it,” he said. “Sea water is salty – thus corrosive – the turbines are metal – they will probably not even last ten years.
“With wind, it has to be blowing at just the right speed and if it blows too hard they have to turn them off. The takeaway from this is Germany and Denmark, who have been going hell for leather for wind farms and now have the most expensive electricity in Europe.”
RAMPION TURBINE FACTS
Each turbine’s foundation is a single steel monopile (between 550 and 800 tonnes) drilled into the sea bed. This is sheathed by a 250-tonne yellow transition piece, and the turbines are connected in strings of 9 to 10 by 70 miles of array cables linked up to the offshore substation via another 27 miles of cable, which have had to be repaired at least twice already.
The seabed is protected by ‘scouring’, the piling of rocks around 46 of the bases.
Each tower is 167 tonnes of steel, and the nacelle at the top (the housing for all the generating components, such as gearbox and brakes) 163 tonnes. Each of the blades weighs 12 tonnes.
At the top of the transition piece, on the steel tower, an Alice in Wonderland door leads to an internal lift, which elevates engineers to a balcony at the top.
The total weight of each turbine, including its foundation, is on average 1,307 tonnes – it varies because of the varying water depth and geological site conditions of each one.
Power is sent to Brooklands Pleasure Park at Worthing, then through cables buried in a trench through the South Downs National Park to the power station at Twineham.
‘Rampion’ earned its name from a school competition. It’s the name of a wild flower indigenous to Sussex.