Reporter
Earlier this week the government reassured the energy sector that the price of offshore wind could be reduced from an average of £140/MWh down to a mouth-watering £100/MWh before the end of the decade. While the story made the headlines, there wasn’t much talk of the new technologies that will have to be developed in order to meet this target.
Phil De Villiers, the Carbon Trust’s head of offshore wind, was giving an overview to a small group of journalists on the technologies that he and his team on the Offshore Wind Accelerator Programme (OWA) believe will be key.
In order to achieve the government’s target of generating 18GW of offshore wind electricity by 2020, there is a need to develop offshore wind farms in ‘Round 3’ sites that are further offshore where stronger winds and larger waves exist. Even then, many sceptics argue that this figure is unattainable.
The OWA programme was partly set up because the Carbon Trust claim that current technologies on the market are not suited to the conditions found at Round 3 sites. Through the OWA programme, the Carbon Trust is dedicating £45m to develop a range of new technologies that could help deliver a 25 per cent reduction in the price of offshore wind energy.
Generally speaking these technologies can be broken down into four groups, including: access systems, electrical systems, foundations and wake effects.
Access systems relate to the vessels and transport systems used to take crew out to the turbine for operations and maintenance – essential to keep the turbines spinning and generating electricity.
De Villiers explained operations and maintenace costs account for 25-30 per cent of the total cost of offshore wind energy. ‘Anything you can do to drive that down is very useful,’ he said. ‘A large component of that [percentage] is unavailability of the wind farm so if it’s sitting idol because there is a technical problem and it’s not generating electricity then you’re not getting the revenues.’
Today, the best vessels today can only operate in 1.5m of significant wave, which means there are approximately 200 days per year when technicians can reach the turbine.
‘If you can increase it to 3.0m then you get something more like 310 days a year which means its much more credible for operations and maintenance at Round 3 sites,’ said De Villiers.
Over the last year the OWA programme has been providing financial and technical support to 13 access system concepts, which include six new vessels, new bridges, robotic arms and pivoting decks.
The vessels have been designed with unique stabilizing technology so that there is limited movement when transferring crew onto a turbine and transferring the crew to and from the windfarm’s mothership, which is where the crew would sleep.
Vessels being developed include the Nauti-craft, which has a suspension attached to each hull, and the Umo Mandal high-speed Surface Effects Vessel (also used by the military), which is capable of 30 knots and will be used in situations where there is a tight weather window.
With regards to electrical systems, there is a need to introduce higher voltage arrays, which have improved reliability, lower losses, and require less cable. Current cables are 33kV but OWA are hoping they can help someone develop a 66kV cable.
The foundations of offshore wind turbines in relatively shallow waters have traditionally been supported by monopile structures. However, there is a need to develop more capable foundations as turbines are moved into deeper waters with larger waves, as monopiles don’t fare very well beyond 30m. OWA is supporting four new foundation concepts including Keystone, which comprises of a guide structure with three supports, and the Clifford BMT Freyssinet, which is a novel float out and sink concept.
Finally, the research on wake effects is all about optimising the layout of wind farms based on where the wind blows most efficiently. ‘One of the findings is that if you have more turbines around the perimeter of a windfarm you get a higher yield,’ said De Villiers.
In order to meet the target figure of 18GW by 2020 then it is crucial that the technologies continue to receive backing from the likes of the OWA programme. However, such technologies eventually need to be demonstrated if they are to have any hope of making it to market but The Engineer reported earlier this week that this isn’t currently the case.
The ETI’s CEO Dr David Clarke commented on the report’s conclusions.
Dr Clarke, who is a Member of the Offshore Wind Cost Reduction Task Force Report said:
“The UK is in a fortunate position to have the opportunity to harness offshore wind as a contributor to future energy generation. But we have a responsibility to be both intelligent and prudent in how we exploit this natural resource. We must recognise that today the cost of offshore wind production is an issue that cannot be ignored.
Today’s reports which confirm the belief that the UK can meet the commitment to a cost of £100/MWh by 2020 provides an endorsement to what remains an industry in its infancy. As such it is an industry which needs to work collectively – sharing knowledge and understanding to make the leap forward it needs to reach this price target – and it also needs to learn lessons from other industries such as oil and gas and aerospace that have travelled a similar path previously. By doing this it has the ability to provide economic benefit to the UK over the coming years through both job and wealth creation.
Throughout any future development there remains a need to insulate the end consumer from cost pressures. The industry will only do this through innovation and technology advancement to help make this a reality. The new technology developed has to be focused on offshore and the marine environment, simple adaptation from onshore will not get us to that end goal.
We are seeking to play our part here at ETI by accelerating technology development that can benefit the offshore energy generation industry. We are currently commissioning two projects – both designed to help reduce the cost of production and therefore increase economic viability. Firstly we are developing a floating wind turbine demonstrator in the 5MW to 7MW range to provide a solution for UK and Northern European waters. Our aim is to demonstrate the technology works therefore helping to de-risk future deployment areas for the industry. Secondly we are working with industry partners to design and build more efficient, bigger blades to feature in the next generation of turbine design. This is again to help increase energy production at a cost acceptable to producers, suppliers and consumers.”
When are we going to reralise that even at the price suggested wind power is a total waste of time, effort and resources.
We relied on wind power from about the 14th century and as soon as something better came along we adopted that.
I have seen or heard nothing to convince me that, with a few local exceptions wid power will solve anything.
Great to see more details of the work on offshore wind that has been going on below the radar. Given our huge experience with offshore oil and gas offshore wind offers some great natural advantages for the UK. We should be grabbing that as the Germans have grabbed the opportunity for a number of other technologies. I’ve no doubt Ian Howitt and other naysayers will denigrate anything on wind. If they bothered to read away from their predictable anti-wind briefing notes they might see an incredible opportunity to gain a market lead on a fast emerging technology rather than just leaving it to the Germans, the Sewdes and the Danes. How are we going to provide our low-carbon electricity in 20 years time if we don’t invest now?
Wind power is only any use if there is an energy storage element with it. Pumping water up to a reservoir to allow controlled and constant release of energy through a water driven turbine is a suitable solution. On their own, turbines are not a consisten source of power.
Given that we are only now realising the true implications of filling the atmosphere with carbon dioxide, has anybody thought about the possible effects of slowing the wind down ? We are taking energy from a system, so the system must change – they always do. Perhaps by an insignificant ammount, but has the sum been done yet ?
Unfortunately Ian Howitt is correct wind power is the wrong technology, it’s the one of last resort. Fine to have some contribution from wind, but more reliable sources need to be tapped, such as nuclear, , tidal including tidal barrages such as the Severn. Like wind farms we need to force through the building of these other energy sources, taking a stronger stance against so called environmentalists who object.
If nothing else alternatives such as the Severn barrage should take precedence over funding for wasted projects such as HS2, which is going to need electrical power, unless of course it will only run when the wind is blowing!
Mike – Yes there are proven local effects due to wind farms and I suspect there will eventually be wider effects if enough energy is extracted. Some of the effects might of course be beneficial ones but it does depend on your viewpoint!
As the old weather folk lore say’s a butterfly flaps its wings in China and results in a storm on the other side of the world. Everything interacts….
In a recent report; ‘UK energy regulator Ofgem in the Renewables Obligation (RO) annual report for 2010/11 show that onshore wind added just £4.68 to household energy bills last year. When factoring in costs for offshore wind, Ofgem’s figures show a total annual price per consumer of £7.74 for wind.’
I am very happy to pay this annual premium for a renewable solution to our energy needs….roll on more wind energy. Keep it coming.
This is not the first time it has been mentioned, but why not re-design the towers to include only a hydraulic pump at the top, an accumulator below, and a hydraulic motor, thus reducing a tremendous amount of weight at the top of the tower?
Wind power can help, but how about a better design of turbine, and geothermal?.
What about SWATH vessels. Apparently they operate very stably in rough seas from the documentary. Or do you frown on Canadian inventions? proven technology as well.
The cost of wind power is actually greater than the full price domestic rate. Moreover much of it will be generated at night and be used at night storage rates of a third of that or possibly to pump water up to Dinorwic which can then be returned to the system but at about 65% efficiency.
A major cost to the generating industry is covering peak demands. Wind is useless for this as there’s no dependability.
It is thus a very expensive white elephant really suited only to replacing costly diesel generated power on islands where transmission from outside is not an economic option.
The chief use of Pumped Storage is to replace more expensive peak lopping generators. Wind is totally useless for that.
Archie
J Stewart… I’ve done my calculations and am shocked at how much volume of water needs to be stored at the height of a wind tower to achieve 1MW-H…. I daren’t show my dodgy calcs… would someone like to confirm how big the tank would be at an average height of say 30M drop… And, let alone, what sort of regeneration efficiency I might expect?
The ‘Nauti-craft’? Really? Sounds just the thing for a pleasure cruise…