Wind turbines are essentially small buckets of
lubricating oil on top of a large metal stick, with rotating wings
attached. Add a strike of lightning, a short circuit or a
mechanical fault and they occasionally set alight. While that might
make a
good photo
, no one’s sure how big a problem it is. A
new report tries
to work it out.

The research by a group of academics from the
University of Edinburgh and Imperial College London for the
International Association for Fire Safety Science (IAFSS) tries to
assess how common wind turbine fires are and how dangerous they
might be. But the researchers ran into a problem: there’s not much
data available.

Fire data

When looking for data on wind turbine fires, the
researchers found many “sources of information are incomplete,
biased, or contain non-publically available data”. So it’s hard to
reliably assess the extent of the problem.

Nonetheless, the researchers give it a go using data
from the – admittedly fairly biased – Caithness Windfarm
Information Forum (CWIF). That’s an anti-windfarm campaign group,
so you can be sure they’ve done their best to record as many
and as serious accidents as possible.

The CWIF recorded a total of 1,328 accidents involving
wind turbines between 1995 and 2012. Of those, 200 involved fire.
There have been no recorded fatalities and four recorded injuries
from wind turbine fires, the IAFSS report says.

That’s 11.7 fires per year on average, or nearly one a
month, the research points out.

While that might sound like a lot, in 2012 there
were 225,000
wind turbines installed globally
, according to
trade association the Global Wind Energy Council. That means you
could expect there to be one fire a year for every 19,230 turbines
operating worldwide, on average. There are
5,569
in the UK.

Data sources

Of course, analysis is only as good as the data
that underpins it. Where does the anti-windfarm group CWIF get its
data? Much of it comes from press reports, so is likely to be
reliable. The database also draws on “private” reports sent to the
CWIF and YouTube videos – and includes things like roof-mounted
domestic wind turbines catching fire, as well as data from larger
windfarms.

One big chunk of the fire reports – 69 out of
the 200 – come from a company called Arepa. Here’s a sample of
Arepa’s
data
. The firm is in the business of
repairing things after accidents, including fires, and almost all
of its reports say they carried out “restoration”. You wouldn’t
restore a turbine that has failed catastrophically – you’d write it
off. That tells us many of the fires recorded in the underlying
data are likely to be minor.

Ten times more fires?

One fire a month around the world doesn’t sound
like a lot, particularly if a proportion of those fires are
minor.

But according to a
report
of the new research in the Telegraph
under the headline “Wind turbine fires ‘ten times more
common than thought’, experts warn”, CWIF’s data may
not reveal the whole story, and the real number could be ten times
higher. Where does this figure come from?

The researchers say trade body Renewable UK
told them there had been 1,500 accidents involving wind
turbines between 2006 and 2010, around ten times more than the CWIF
data recorded for the same time period.

If there were ten times as many accidents, then
surely there would have been ten times as many fires, the
researchers assume. In that case there could have been as many as
117 fires a year on average.

There’s a really big issue with this assumption,
however. Renewable UK director of health and safety
Chris Streatfeild tells Carbon Brief that the 1,500
figure is for “incidents” not “accidents”. What’s the difference?
Incidents includes minor slips, trips or falls as well as actual
accidents.

Streatfield says:

“These are
overwhelmingly near events where no injury, harm or damage
resulted. Far from being a negative – reporting of this type is an
example of industry good practice in that it enables safety
improvements to be made before more serious events occurs. The
extrapolation in applying the data to fire safety by the
researchers is therefore extremely misleading.”

He says that it isn’t possible to break the
figure down to show the number of fires because the data is
recorded according to the severity of the incident rather than
according to what type of incident it was.

That means the 11.7 fires per year is more
likely to be a maximum rather than a minimum figure. In fact, once
we take out the four restorable (so probably minor) fires per year
repaired by Arepa there are actually fewer serious fires than
thought, not more.

Business problem

Given the relatively low numbers of fires and
the fact that they don’t tend to occur in built up areas or spread
particularly quickly, wind turbine fires are probably not putting
many people in danger.

But that doesn’t mean they’re not a problem,
particularly for windfarm operators who lose money every time a
turbine needs to be prepared. Germany’s fire testing organisation,
the VdS, estimates that an operator can lose
€5,000 a week if a 20-year old two megawatt
turbine is out of operation, the report says. It also quotes
another estimate that suggests one offshore wind turbine fire ended
up costing a company about €2 million in
repairs and lost revenue.

If that’s the case, there’s a pretty big
incentive for companies to ensure their kit is fireproof.
Streatfield points out – not unreasonably – that the industry
wouldn’t be able to secure the billions being invested in wind
energy if that money was at significant risk.

Via: http://www.carbonbrief.org/blog/2014/07/new-report-suggests-there-may-be-one-fire-for-every-19,230-wind-turbines/