Wind Turbines: More Ghosts in the Gearbox

There is a wall of silence from the wind industry regarding wind turbine reliability. But once in a while data seeps out through the wall to the general public. A little bit of new seepage has just come to my notice.

The last time I blogged about wind turbine reliability was after I had come across an obscure department within the USA government National Renewable Energy Laboratory (NREL) called the Gearbox Reliability Collective (GRC). The purpose of this U.S. government sponsored department is to address the appalling and largely hidden reliability problems with wind turbines, particularly gearboxes.

The GRC has their own website here: 

My first post on the GRC is On This Link 

The GRC is not alone. Clearly there are several European agencies and groups working on this problem too. Unfortunately information on them is very obscure. I am unaware of any public access to their data other than when it is mentioned by the GRC.

What has just caught my attention is a 2013 paper from the GRC. The  paper is titled: 

Report on Wind Turbine Subsystem Reliability ─ A Survey of Various Databases.

The paper is on this link:

If you look at the linked document above you will find a survey of many wind turbine failure databases held in Europe and the USA.

As far as I can ascertain there is no public access to any of this data except to that presented in this paper. If I am wrong I would be grateful for any links – I have found none.

The figures from Europe in this survey stop short of fully quantifying failure rates. They do though hint at a failure rate increase for larger turbines and crucially, also for direct drive turbines.

We also have the USA data in the same document. Some of the USA data goes right up to 2013. This American data is far more open and definitive. It gives failure rates for all major components not just the gearboxes.

Here is the table (see page 31) relating to expected annual gearbox and generator failure rates for on-shore turbines.

The NREL reckons for gearboxes this averages out at 5% per year for the first ten years. Notice that in year 5 it hits 10%. 

Whatever way you cut it statistically around about 50% of turbines will suffer a gearbox failure within 10 years. Remember this is for properly maintained, serviced and generally “looked after” turbines.

But also remember – that is ONLY the gearbox. The generator is “slightly” more reliable coming out at an average failure rate of 3.5% per year or 35% over ten years.

So for an onshore turbine in the USA the chances of a properly serviced and maintained turbine failing due to gearbox or generator issues within 10 years is 85%.

If you include the other potential failure areas (say the blades - failure rate quoted at 2% per annum) then statistically, it is almost surely that a properly maintained and serviced wind turbine will suffer a major failure within 10 years. It looks like most failures will occur in year 5 or 7.

All rotating machinery can (and will) break down. But wind turbines are operating in a chaotically changing and hostile environment (offshore turbines even more so). A gas plant by comparison is operating in a closely controlled and regulated environment. So per Megawatt-Hour, the wind turbine will require much more maintenance.

The energy return from a wind turbine is simply inadequate to pay for the very high demands placed on maintenance and repair. As the machine gets older more maintenance and repair will be required. Eventually the point will be reached (7-10 years?) where the maintenance/repair bills exceed the returns.

The often hyped 25 year life span for a wind turbine would appear to be hopelessly optimistic.

Currently the only way round this problem is to hugely increase the price of the electricity generated by the machine from day one. This is essentially what the current government subsidies do.

But one day the subsidies will have to fall. When this happens, or as the turbines get older and more unreliable, the wind farms will end up being be sold on - and on.

The new owners will be ever more dubious organisations. Eventually the turbines will be run until they suffer the final major failure that renders the turbine beyond economic repair. Then they will be abandoned.

When the last one fails and the payments stop, the bailiffs will arrive to claim the “guaranteed” decommissioning fund. But by then the main company office will be a post box in Belize and the decommissioning fund will be long gone.

Remember almost all of the data in the above paper is for on-shore turbines.

When you go offshore the maintainability and reliability falls off a cliff. The consequent subsidies sky-rocket.

But more on that in another post.

Sendai Nuclear Reactor Restart

Both Sendai reactors (unit 1 and unit 2) have now been restarted. Sendai unit 1 has just started providing electricity to the grid. (August 14th)

So how will this affect Japans Carbon Dioxide emissions? And how would renewables (say wind) compare?

When nuclear was shut down in Japan it was replaced with an unholy mix of coal and gas (with about 7% oil) A rough estimate of the amount of Carbon Dioxide from the generation that replaced nuclear would be around 750Kg of Carbon Dioxide for every MegaWatt Hour of energy generated (750KG/MWh)

Sendai, during its last year of full operation generated just short of 13TWh of electricity (13000 GigaWatt Hours) So today, the first day of generation, Sendai unit one (half of the power plant) will have generated around 18GWh of energy. This will displace energy that would have otherwise been generated from the coal/gas/oil mix

So a rough estimate of the amount of Carbon Dioxide prevented from being dumped into the atmosphere by this single day of generation from half a nuclear power plant amounts to 18000 x 750 = 13.5 million Kg of Carbon Dioxide or 13500 Tonnes.

A single day of operation from half a nuclear power plant prevents the emission of 13500 Tonnes of carbon Dioxide.

Amazing isn't it?

How would a renewables option compare?

An 150m high 2MW wind turbine with a typical 25% capacity factor would intermittently produce 12MWh in a day. Or using same units as Sendai - 0.012GWh

So to match the single day output from half of Sendai nuclear power plant (and ignoring the problems of intermittency) would would need 1500 turbines.

Or to put it another way, for a single turbine to match a single days energy generation from half of Sendai nuclear power plant would take that turbine four years, one month and nine days.

Don't figures like that just knock you out?

Lies Propaganda and Methane

I find myself an unlikely defender of fracking. This is not because I think there is anything particularly dodgy (or wonderful) about fracking but because I think that gas is only useful in the short term. The hope for a low pollution low emissions future lies firmly with nuclear.

Even so, I feel I need to blog the rampant scare mongering, lies and black propaganda surrounding what is a relatively minor modification to a well established industrial activity.

I wont bore you with yet another synopsis of fracking or how fracturing rock in non horisontal wells has been common practice for about 40 years. Instead I'll cut straight to the fear mongering surrounding fracking.

Fear Mongering Item One: Water Table Pollution

After years of outright lies, faked or irrelevant videos (including flaming faucets) and other general hysteria about water table pollution, the US Environmental Protection Agency produced a mammoth report on the potential and real impacts of Fracking on drinking water (Executive Summary Here)

This report, while carefully worded, essentially demolishes the whole basis of the propaganda alleging widespread pollution and water contamination from fracking.

True, there have been a small number of spills and pollution incidents, mainly from poor well head and surface maintenance. These have been dealt with and in some cases prosecuted as you would expect.

In the USA, fracking is a very, very large and diverse industry. Sadly occasional errors do and will occur. All industries suffer similar and often much worse failures.

But rampant water table pollution? No.

Black propaganda always has a shelf life. Today the lies and gross exaggeration peddled about fracking and water table damage is now pretty much an embarrassing busted flush.

So instead, now we have:

Fear Mongering Item Two: Methane Leaks

Using natural gas (Methane) as a replacement for coal in Electrical generation cuts the Carbon Dioxide emissions by about a half. That is why people are excited about it as a way to reduce Carbon Dioxide emissions.

Since around 2007 when Fracking took off in the USA Fracking gas has replaced coal to such an extent that USA Carbon Dioxide emissions from electrical generation have been reduced by about 15%.

Her is a graph on how its dropped in the last few years.

It might not look like much but it is the largest drop for any country in the world in the last ten years. Today Dirty USA has electricity emissions that are lower than Energiewende obsessed Germany.

Notice how the drop correlates with the rise in fracking in the graph below.

So whats not to like?

Methane is a Greenhouse gas about 25 times more virulent than Carbon Dioxide. So if you use Methane to cut down Carbon Dioxide emissions by replacing Coal with it, but then manage to lose somewhere between 4 and 7% of your gas into the atmosphere you end up back at square one. Lose a higher percentage and you are in negative territory.

(First of all - as an analogy, would you happily slop close on to a gallon of fuel over your shoes every time you filled your car because the filler cap leaked? Or would you get it fixed?)

The general anti-fracking hysteria surrounds a respectable 2013 paper by Karion Sweeney et. al. In their paper on a single day they measured rogue Methane above one area of the USA. They found leakage rates corresponding to 6-11%.

Is that bad? Yes.

Does it need investigating further? Yes.

Does it mean that gas fields in USA are leaking between 6-11%? No.
(Paper is Here)

To be fair to Karion, Sweeney and colleagues - they do say in the introduction:
This study demonstrates the mass balance technique as a valuable tool for estimating emissions from oil and gas production regions and illustrates the need for further atmospheric measurements to determine the representativeness of our single-day estimate and to better assess inventories of
CH4 emissions.

The main and most definitive source for data on Methane and other gaseous emissions in the USA is the US EPA (Environmental Protection Agency). They have been accumulating evidence on American rogue Methane for over 30 years.

Firstly the EPA have produced a breakdown of the different industrial areas that release rogue Methane. (document ref Here )

They also give an idea of Methane release by year.

From this graph we see rogue Methane from all sources has actually fallen by 15% since 1990 to 2013. The greatest decrease has actually coincided with the massive shale gas bonanza from 2007. Furthermore the EPA state that while rogue Methane has fallen by 15%. the rogue Methane emitted by farming has actually risen and has been offset by a bigger fall in release of rogue Methane from the oil and gas industry. So while fracking has been rapidly expanding, Methane loss has actually gone down in the oil and gas industry by somewhere between 15-20%.

The main reason organisations like the FoE continually promote mistruths about Methane release is because of the success Gas has had in cutting Carbon Dioxide emissions in the USA while their poster boys of wind and solar have barely scratched the surface. Gas has shown us how their dogmatic obsession with wind and solar has led us all down a blind alley.

We must make sure we judge fracking in the UK by the plentiful scientific evidence from the USA and not by the manipulated half truths from the FoE.

Sendai Restart and an Early Christmas Gift

The anti-nuclear lobby is getting all bent out of shape by the restart of one of the two reactors in Sendai in Japan. The restart of one of the worlds most effective anti-greenhouse-gas and anti-pollution power generation methods really rubs their medieval superstitions right up the wrong way.

Not to be outdone by the Sendai reactor, I thought I would indulge in a bit of Luddite antagonism as well.

Of course the best way to antagonize a superstitious hysterical self feeding fear monger is by referencing some impeccably researched and peer reviewed science and then to couple that to a small amount of simple mathematics to show that nuclear actually saves lives.

So here goes....( all figures rounded to one decimal place)

Take one Pressurised Water Reactor. As it has just restarted, we'll use the Sendai Reactor - See Wikipedia Here

The Sendai reactor produces just short of 13TWh of electricity per year. As they have only started one of the two reactors on the site then that will be around 6.5 TWh.

Or to look forward to the festive season: 2.2TWh by Christmas.

Now as for out impeccably researched and peer reviewed let us take this table from a paper by Markyanda & Wilson (published in the Lancet, referenced by Jim Hansen among others) (Full Paper Here)

I suppose we should figure out what fossil fuel the Sendai nuclear reactor displaces .... From an earlier post here we have the break down of what has replaced nuclear during the shutdown in Japan. (Post is Here)

Basically it breaks down as follows. Nuclear in Japan during the shutdown was replaced by:

46% Coal
47% Gas
7%   Oil

So the single restarted Sendai reactor (6.5 TWh/yr) will displace approximately 3 TWh coal, 3 TWh gas and 0.5TWh oil in a year.

Or if we want to get into the festive spirit, the Sendai restart will displace approximately 1 TWh coal, 1 TWh gas and 0.2TWh from oil by Christmas.

Lets rephrase these figures into death and illness using the table above.

The deaths, disease and illness prevented in a year from the single unit restarted at Sendai ( i.e. half of a solitary nuclear power plant) will cut pollution by such an extent that it will:

Prevent the deaths of 90 people
Prevent serious illness (hospitalization) of 840 people
Prevent minor (time of work) illness of 45000 people (yes you read it right - 45 thousand)

Or to simply look to Christmas 2015. This single restart late in the year (August) will.

Prevent the death of 10 people
Prevent serious illness in 91 more
and prevent minor illness in no less than 15000 people

Now whether you are a Luddite or not, that is a hell of a Christmas present for 15100 folk in Japan this year.