The problem with O&M

22 renewable energy focus January/February 2009

Wind/Operation & Maintenance

The problem with O&MFRANK MASTIAUX, CEO OF E.ON CLIMATE AND RENEWABLES

RECENTLY SAID THAT IF COMPANIES SUCH AS E.ON ARE TO REALISE

THEIR PROJECT PIPELINES AND GET MW ON THE GROUND, THE

WIND INDUSTRY HAS TO MOVE FROM “BOUTIQUE TO TRULY

INDUSTRIAL LEVELS OF OUTPUT”. BUT AS THIS HAPPENS AT AN EVER

INCREASING RATE CREDIT CRUNCH OR NO CREDIT CRUNCH, HOW

CAN PROJECT DEVELOPERS AND TURBINE MANUFACTURERS ENSURE

THAT THE TWIN DEMONS OF POOR TURBINE RELIABILITY AND HIGH

COSTS OF O&M BOTH WELL DOCUMENTED DO NOT CONSPIRE

TO REDUCE THE POTENTIAL SCALE OF WIND POWER?

renewable energy focus January/February 2009 23


Over the next few issues In a new, regular, column, Renewable Energy Focus

will look at various aspects of O&M.

In the first installment, Matthew Jackson and Stephen Rogers from the Arthur

D. Little consultancy suggest how Offshore wind can overcome its various

obstacles (see pages 24-27).

But first, Jack Wallace, wind turbine technical advisor with US-based Frontier

Pro Services, asks whether extended periods of downtime might not just be a

problem of faulty turbines, but rather on occasion be down to the lack of exper-

tise – and poor attitude – of the O&M teams themselves…

Downtime and your O&M team – turbine availability begins at home

With all the various and uncontrollable causes of turbine downtime that

wind park owners and operators are all too familiar with, there remains a

frequently overlooked, entirely manageable cause of turbine downtime:

the operations and maintenance (O&M) team.

The most important issue for any wind park operator is to ensure the

turbines are available when the wind is on. As wind parks proliferate and

turbine technology becomes increasingly complicated, the shortage of

qualified wind energy technicians is taking a significant toll on downtime.

The stress on O&M that leads to turbine downtime takes many forms.

Insufficient training, poor employee motivation, engineering problems,

over-complicated and over-controlled procedures, lack of a sense of

urgency, as well as the O&M team’s failure to apply an appropriate atten-

tion to detail.

The most important success factor for any wind park operator is turbine

availability – when the wind is blowing, the blades must be turning. The

cost of downtime from O&M inefficiencies can be difficult to calculate.

The difference is often hidden; meaning that many days of wind can hide

one day of a turbine being off line.

However, these outages add up to significant lost revenue when averaged

over the course of a year or the lifetime of the wind park. Wind parks that

deliver superior financial returns typically have well-trained, highly moti-

vated O&M teams that are driven by incentives crafted to ensure the

blades will turn whenever the wind is blowing.

As a wind technician and field consultant for more than 20 years, I have

heard and seen some mind-boggling and maddening things. Once a few

years ago, I was discussing a customer’s O&M challenges with him, and he

told me in all sincerity that “wind is our enemy.” That was as backward and

disheartening a thought as I could imagine!

So, I began to talk with him and his team further to understand what had

them all so frustrated. I discovered that they were understaffed or staffed

with unqualified people, and that the O&M team’s efforts were unappreci-

ated insofar as their often times extraordinary service efforts were not

acknowledged or recognised in anyway.

Unrecognised for their work to keep the turbines up (or down!), their

motivation to answer middle of the night calls to reset faults was clearly

waning – and wind had become the enemy.

It is true that a good portion of downtime on wind parks is related to the

engineering of the wind turbine. Major component failures are usually not

the fault of an O&M team. If a wind turbine component is poorly engi-

neered, it will make itself known very quickly to those in the wind industry.

About the only area of design that allows field efforts to affect reliability

is in the control system. Today’s wind turbine control systems can be over

stacked with complexity. The turbine controllers are over protective,

complicated and not user-friendly. Such controllers make troubleshooting

difficult, especially if the wind turbine’s theory of operation is not made

bluntly evident.

But if you have a specific wind turbine, or wind park, then that is what you

get. That decision is a 20-50 year decision. It is final. In all probability no one

is going to be replacing that turbine with another design anytime soon. So,

the wind park operator needs to change his mindset from the list of prob-

lems inherent in the turbine’s design to creating a best-in-class operations

plan for keeping the turbines running. Eventually the engineering problems

will be worked out, and all that will be left to fix will be up to you.

For years I drove past a wind park that always had many machines off. I

assumed that the turbine had a bad design and that that was the reason

for such poor operations. Ten years later, and I am now running that wind

park with a team of my technicians. The problem was not design. It was

operator motivation. The operator did not try very hard. Today, that same

wind park is now operating in its 23rd year, and running well.

Maybe the manufacturer will help you get the machines running, maybe

they won’t. Regardless, the reputation of your wind park is up to you. You

know if you are trying or not, and so do your co-workers. Making the

machines run is priority one. Yes, it’s challenging work; but it is the work

of the O&M team. We are not talking wind turbine efficiency here. We are

talking about reliability and run time. If you can keep them running in

wind then you are doing your job. All incentives, recognition, processes

and procedures must be in line with this fundamental objective: the wind

turbines must be available when the wind is on.

As far as efficiency problems go, they are engineering problems and have

to be built in. If you find yourself with time to worry about efficiency – that

is icing on the cake. The bulk of the problem, though, is ensuring the

turbines are running.

I have worked with many different types of wind turbines. The number one

cause of nuisance faults causing downtime are controller issues. Once you

have the controllers working properly, then the next most common cause

of downtime is technician-related.

“Wind parks that deliver superior financial

returns typically have well-trained, highly

motivated O&M teams that are driven by

incentives crafted to ensure the blades will

turn whenever the wind is blowing.”

Jack Wallace, Frontier Pro Services



Controllers for wind turbines are becoming major technical innovations.

Turbines are using controllers with thousands of parameters. Any little burp

causes the entire machine to shut off requiring a reset, either remotely or

an onsite reset. If it is the end of the day, windy, and a turbine is off, you

need your technicians to go out and look at the machine. This is the differ-

ence between the turbine being off for 1 hour or overnight for 15 hours.

More and more wind park O&M teams are not accepting the responsi-

bility for ensuring that the turbines are running. As wind parks go main-

stream and qualified technicians become scarce, a proud and elite

profession is adopting very mainstream problems including low motiva-

tion, selfishness, lack of ambition, laziness, carelessness, “just a job” atti-

tude, all of which are very dangerous in an industry that services

massive machinery.

The best run wind parks do not necessarily have the best machines, they

just have the best motivated technicians with incentives aligned with the

primary objective: keeping the turbines running.

We all hear the grumbling from technicians about poorly designed

machines. However, the machines you have are the machines you have.

That’s it. It’s all you get. If you want other types of machines to work on,

then by all means move to another wind park. But I guarantee, if turbine

problems make you grumble, you’ll be grumbling at any wind park. The

best technicians accept the challenges, and just work the problems they

know they have – and keep the turbines running!

Jack Wallace Jr., Frontier Pro Services

Offshore wind –

how can it overcome the O&M obstacles?

The offshore wind market is a small but growing part of the world energy

market. Total capacity reached 1 GW in 2007 (around 0.01% of global energy

capacity) and is set to increase sevenfold over the next five years. Activity is

currently confined to Europe. The lack of take up in other major markets such

as the USA and China is due to the abundance of available land in these

countries, meaning that Governments have little incentive to subsidise

offshore developments.

Offshore wind project update

The UK’s Thanet offshore wind farm has been saved by Vattenfall’s £35m purchase of the project. ScottishPower had been due to purchase the project, but pulled out late into negotiations. Onshore construction work had already begun on the project, with foundation installation due to start before the end of 2008. Foundations will now go in starting in February 2009, using A2Sea’s vessel Sea Jack. Installation of the 100 Vestas V90 turbines will take place in 2010 and will be performed by Marine Projects International. Commissioning on the £780m project is due by the end of 2010. Vestas is supplying 100 turbines with total capacity of 300MW.

The high cost of the Thanet project and other forthcoming projects is cause for concern. Major developers such as Centrica have previously expressed concern. For the UK, the falling value of the pound against the euro is exacerbating fears, as is the overall economic slowdown. There is a risk that some of the more expensive projects will be postponed or cancelled. Developers may attempt to bring in new project partners to help share costs on the large offshore wind farms.

Supply chain constraints will be an additional factor on projects due post 2010, with an increasing number of projects competing for resources each year.

Late last year, the jack-up Titan-1 was lost at sea during transportation from the US to the UK. The jack-up was being moved from Pascagoula, Mississippi, to Liverpool ahead of starting an 817-day contract in the North Sea. The job would have covered the installation, servicing and maintenance of wind turbines off Denmark and the UK. The first project was aiding with installation at the 90 MW Rhyl Flats project off north Wales.

Despite this loss, the Rhyl project is on schedule for completion in summer 2009. Other UK activity ongoing includes the 172 MW Gunfleet Sands project (consisting of the Round 1 and Round 2 projects combined), due for completion in autumn 2009. Installation work at Robin Rigg is well progressed, albeit behind schedule, with completion of the 180 MW site due in 2009.

In Scotland, the bidding process for the Crown Estate’s separate

licensing process saw 23 projects put forward from 14 companies or joint ventures, a higher response than first anticipated. It is hoped that the first of these projects would enter construction around 2016. The actual permitting process these projects would be subject to has yet to be determined.

Denmark’s Horns Rev II project is well underway, with foundations all installed and cable installation taking place at present. Turbine installation will begin in March and is to be undertaken by A2Sea. The project remains on schedule for completion at the end of 2009. This will be the first offshore completion in Denmark since the first Nysted project was built in 2003.

The other major current project off Denmark is an extension to the Nysted wind farm. The Nysted II project will see gravity base foundation installation start in February. Turbine installation and commissioning of the 207 MW project, which uses 2.3 MW Siemens turbines, will take place in 2010.

A new 400 MW project is to be built between Djursland and the island of Anholt. The Danish Energy Authority has arranged environmental assessments of the site, the cable route and also geotechnical investigations. After an expression of interest early in 2009, full bids are expected by summer 2010. The Danish Energy Authority want the project to come online by the end of 2012. Eon, Dong and Vattenfall are expected to bid.

continued on c1, page 26

“For years I drove past a wind park that

always had many machines off. I assumed

that the turbine had a bad design and

that that was the reason for such poor

operations. Ten years later, and I am now

running that wind park with a team of my

technicians. The problem was not design. It

was operator motivation.”

Jack Wallace, Frontier Pro Services



The problem

Theoretically, offshore wind should be a low risk investment, in that fixed

costs represent a high proportion of overall costs. This provides a level of

certainty which, combined with guaranteed tariffs, makes it particularly

attractive during times of volatility. But offshore installation is roughly

50% more expensive than for onshore, and O&M costs are roughly twice

as much.

In this regard, technical problems present the biggest potential risk to the

future of the industry. Technical failure rates in offshore wind can be high

compared to onshore, and offshore failures are difficult and expensive to fix.

This is underlined by an analysis of maintenance records, which shows

that while service teams for offshore wind farms are supposed to make

two scheduled maintenance visits every year, unscheduled visits to many

installations are made 20 times a year.

Why do turbines fail?

The heart of the problem is that the technology being used offshore is

generally onshore technology that has not been modified sufficiently to

meet the different demands of an offshore environment.

The classic example of this is the disaster at the Horns Rev wind farm in

2005, following which Vestas is reported to have removed and repaired

80 of its V90 models, designed for offshore use, owing to the effect of

salty water and air on the generators and gearboxes, which became

corrupt after only two years. A similar procedure has been reported this

year, with Vestas’ 30 turbines requiring a change of rotor bearings, at an

estimated cost of €30m.

Failures are also harder to repair because they tend to happen in stormy

conditions, and are often not dealt with when they happen, but on an

aggregated basis at intervals. That means it can be as long as three

months before a turbine failure is repaired. The contrast with onshore

reliability is dramatic, and availability levels of 97% are regularly

achieved.

As sites move further offshore, these problems are likely to get worse.

That could mean offshore developments in deepwater areas will be seen

as unviable. For example, all the potential sites in the German North Sea

have been allocated, but it is uncertain as to whether investment

will follow.

The gearbox

The main area of concern in the industry surrounds the gearbox. The

reason for gearbox failure is currently not a matter of universal agree-

ment. Data indicates that gearbox failures onshore are in line with

industry averages. Offshore, it appears that gearboxes in fact perform

better than other parts of the turbine. The problem with offshore turbines

is that conditions are more extreme, and the downtime which results

from the replacement of a gearbox has a greater effect on availability

compared with, for example, the failure of a generator. The technology of

offshore gearboxes therefore needs to improve, and when it does, this will

have a dramatic effect on availability levels (nb: in next month’s issue the

O&M column will cover the Gearbox – ed).



The direct-drive system, pioneered by Enercon, and which bypasses the

need for a gearbox, could be held up as a solution to this issue. The initial

higher costs would be repaid by lower maintenance costs and higher

uptime levels. Siemens Wind Power is another organisation currently

testing a Direct Drive model.

Realistically, the step-change required in the manufacturing facilities of

the other main suppliers of turbines, all of whom use gearboxes, would

be too great, and we are unlikely to see the disappearance of the gearbox

in offshore installations, particularly considering the huge weight of the

direct-drive system (up to 500 tonnes).

Less rigorous testing is required for onshore turbine components, as they

can be replaced with relative ease, on a ‘fire-fighting’ basis, whereas with

offshore this is not feasible. For gearboxes, then, better testing will be a

key requirement as part of – and in addition to – the development of the

technology. Offshore blades are currently tested very thoroughly, and

perform relatively well considering that they receive the bulk of the

torque to which the turbine is subjected. Generators are not tested as

rigorously, and do not perform as well offshore.

Improved testing for gearboxes might involve breaking prototypes rather

than subjecting them to limited loads as is common now. Suggestions for

improving the design itself include making the gear case more flexible,

and possibly reducing the size of the gearbox, to two stages rather than

three.

Another solution that is not currently being considered is the possibility

of complete nacelle testing. Currently the first time the components work

together is when they are part of a live turbine.

The bottom line for technical difficulties is that they have the potential

to cripple returns, and thus the risk profile of projects is increased and

their economics more dependent on generous Government support –

not a sustainable model for the future of an industry that aspires to be

a key source of world renewable energy.

What is needed?

The change needed for the industry to secure its long-term future is for

the technology to become more robust and reliable:

■ Better design of individual components (i.e. smaller, two-stage gear-

boxes); the drive train (smarter integration of key components) and

foundations;

■ Increased levels of R&D – not only in design, but also access and

maintenance methods;

■ More thorough certification testing so components really can with-

stand the offshore environment.

Analysis from Arthur D. Little shows that testing is probably the crucial

element that will stimulate work in the other two areas. To date, testing

has clearly been inadequate. Manufacturers have claimed it is possible to

test onshore without the expense of offshore testing. However, there is

clear evidence that, while it may be possible to test individual compo-

nents onshore, running a turbine in real offshore conditions for at least a

year would bring to light many key problems and save considerable

amounts of money.

Such testing has already been shown possible, albeit with Government

support. In Germany, for example, offshore testing is already taking place

at Alpha Ventus (albeit on a partly commercial basis).

Marine project update

Atlantis Resources Corp., has signed a Memorandum of Understanding with the CLP Group which lays the foundation for Atlantis to collaborate with CLP in the development of commercial-scale tidal current renewable energy generation projects across Asia-Pacific. This, together with agreements with partners in other regions, will bring Atlantis’ total electricity generating project pipeline to over 800MW. Sites under investigation span Asia-Pacific, Australia, the UK and North America, positioning Atlantis as a genuine pioneer in global tidal energy generation.

Atlantis recently completed trials of its Solon tidal current turbine and the commercial launch of a 2MW Solon turbine is expected in summer 2009. Last month, the company announced plans to build a tidal energy-powered data centre near Scotland’s Pentland Firth.

Aquamarine Power Ltd has appointed ABB to complete the electrical engineering design and construct the electrical generating system for Aquamarine’s Neptune tidal stream device. With a contract worth over £2million, ABB will also install and commission the system at the European Marine Energy Centre

(EMEC) in Orkney, where Aquamarine will demonstrate the first full-scale Neptune device.

Marine Current Turbines Ltd (MCT) has agreed a partnership with Canada’s Minas Basin Pulp and Power Company Ltd (MBPP) to demonstrate and develop tidal power technology and facilities in Canada’s Bay of Fundy, Nova Scotia. MBPP of Hantsport, Nova Scotia is a sustainable energy and resources company. Working in partnership with MBPP, MCT will participate in the tidal power demonstration centre established by the Province of Nova Scotia. MBPP and MCT intend to deploy a 1.5MW tidal generator when the in-stream tidal energy centre enters full operation and is connected to the Nova Scotia grid.

The Scottish Government has granted consent for the Siadar wave energy project on the Scottish island of Lewis. npower renewables, a UK-subsidiary of RWE Innogy will be the operator of the planned facility with Wavegen, the Scottish subsidiary of Voith Siemens

Hydro Power Generation, the technology partner for the wave power units. Both npower renewables and Wavegen have been working together on the project since 2006.

Adam Westwood, Douglas-Westwood Ltd.

Another solution that is not currently being

considered is the possibility of complete

nacelle testing [for offshore wind turbines].

Currently the first time the components

work together is when they are part of a

live turbine.



All this work will need to be underpinned by collaboration. To date, the

industry has been characterised by a general atmosphere of secrecy and

suspicion and, as a result, there has been fragmentation of knowledge

and lack of research progress.

The catalyst for change will come from a shift in the balance of power

away from the wind turbine manufacturers towards bigger and more

experienced customers.

These customers will have the knowledge as well as the muscle to make

specific demands for improvements in testing and development in a way

that was impossible for small wind farm owners. These higher standards

will filter all the way down the supply chain and are likely to result not

only in better design, but also better type testing of components and

integrated systems during the production process.

At the moment, individual company research into the causes of

mechanical failures or ways of improving access and maintenance may

be prohibitively expensive. Collaboration can reduce those costs

significantly. In terms of testing, greater openness would facilitate the

testing of integrated drive trains. Independent testing facilities – such as

the New and Renewable Energy Centre (NaREC), in Blyth, UK – should

continue to be used as a neutral location for such tests to be carried out

without compromising secrecy. It is true that such shared schemes have

been tried before and not succeeded, but in a changing climate these

options will need to be considered again.

This kind of collaboration is not unusual in the energy sector. In offshore oil

and gas, for example, E&P companies have collaborated for years on access

and maintenance issues, and the results have benefited the entire industry.

This shows that there is a clear model to follow.

Action is therefore needed from offshore wind farm owners and developers

to apply pressure on turbine suppliers to ensure they invest in rigorous

component testing and robust offshore-specific R&D; apply pressure on

turbine and component manufacturers to take a long-term view and invest

to secure a sustainable future for the offshore wind market; and finally help

is needed from Governments to free up funding for public R&D centres, and

projects that can act as catalysts for industry collaboration and ‘open research’.

What should particularly concentrate minds in the offshore wind industry

is the clear message that without collaboration, the offshore wind industry

will not mature or progress.

About the authors:

Downtime and your O&M team – turbine availability begins at home

Jack Wallace Jr., is a wind turbine technical advisor with Frontier Pro Services

+1 951-849-3194

[email protected]

Offshore wind – how can it overcome the O&M obstacles?

Matthew Jackson is a business analyst in Arthur D. Little’s Energy and Utilities practice.

Stephen Rogers is a director in Arthur D. Little’s London office.

mailto:[email protected]

Documents

The problem with O&M