How Long Do Wind Turbines Last? 10 Years or Until The Subsidies Run Out (Whichever Occurs First)

Wind power outfits still claim their turbines run on the smell of an oily rag and last for 25 years or more, needing little more than a hug from time to time.

However, the operations and maintenance cost of these things, as reported by Australia’s Infigen, is around $25 per MWh (hardly the zero marginal cost claimed by wind cultists!). And, as we’ll detail a little later in this post, wind turbines are unlikely to have an economic lifespan beyond 10 years.

But first this, from Energy Wire (a renewable energy propaganda site) – indicating that the only thing that keeps them running is an endless stream of taxpayers’ money.

DOE lab: Turbine power plunges when tax credits go away
Energy Wire
David Laconangelo
21 May 2020

Wind farms often produce less power when they age past the 10-year mark because the loss of federal tax credits halts maintenance – a finding that could shift policymakers’ plans for climate policy, according to a new study from Lawrence Berkeley National Laboratory.

The research, published in the journal Joule last week, is the first comprehensive account of how wind turbines across the United States degrade over time, according to researchers. Wind made up close to 8% of the nation’s power last year, when it overtook hydropower as the largest generator of renewable electricity.

The lab found that after the first 10 years of operation, wind turbines tended to experience an “abrupt decline” in performance, which continued as time went on. They produced less electricity than possible given wind conditions at a specific site.

The sudden drop-off suggested that the plants’ operators were doing something different: Since they could no longer profit from the decadelong production tax credit (PTC), companies were doing less to protect against wear and tear, having apparently decided it no longer made good financial sense, according to the paper.

After 17 years, the lost energy was equivalent to taking away 1 out of every 10 turbines in a wind farm, said Dev Millstein, a scientist at LBNL and co-author of the study.

The finding could lead some policymakers to reconsider how they value wind in the future, researchers said.

“A lot of times, the degradation of wind plants’ performance over time gets ignored,” said Millstein. “If you’re making decisions for a 20-year lifetime, it starts to matter – or if you’re estimating the cost of a project.”

Under pressure from emissions reduction laws, power companies in many states are elevating wind’s role in their long-term plans for sourcing electricity. And utility regulators, grid operators and other officials tasked with protecting grid reliability are in some cases banking heavily on wind power. In New England and the Mid-Atlantic, for example, several states have effectively ended new gas pipelines in hopes that a future fleet of giant offshore wind turbines will fill in the blank.

“The main use of these results are to help get accurate projections of how much energy wind plants are going to provide over their lifetime,” Millstein said. “That’s beneficial to the industry and to long-term planners because you’re not misrepresenting the amount of energy your plant might generate.”

Wind farm operators have a number of life-prolonging maintenance options at their disposal, including software updates, component replacements and subtler measures that protect blades from erosion.

Even after the 10-year PTC period elapsed and companies discontinued those kinds of activities, though, the U.S. fleet continued to perform fairly well compared with those of other countries, noted Millstein.

Newer wind turbines, or those built after 2008, have also proved more resilient during their first decade of life. Longer blades have allowed turbines to operate at full capacity under less windy conditions.

However, those might also see a drop-off in performance after a decade, said Millstein. “Hopefully, we get to do the research in a few years, once we have data,” he said.

“But my hypothesis would be that we’ll see some of the same behavior, where they lose some of the performance,” he added.
Energy Wire

When a 3½ year old Suzlon S88 turbine at Infigen’s Woodlawn wind farm died of premature bearing failure back in 2015, on ‘message’ and true to form, one of its spruikers first claimed that its turbines run for “25-plus-years”; and then went on to claim that a wind turbine seen with its blades removed “had a failure of the main bearing. This is the only known failure of this turbine type and is very rare for wind turbines in general. The cause is still being investigated”.

The furphy concerning the rarity of bearing failure is pretty easy to skewer: mechanical wear and tear, including bearing failure is one of the most common reasons for turbines to be put out of action; and is one of the key factors that accounts for the fact that the ‘economic’ life of wind turbines is 10-12 years, which runs contrary to wild claims about them lasting for “25-plus years” (see our post here and this paper).

Top flight German turbine maker, Siemens booked a €223 million write down (ie loss) in 2014 due to the fact it has had to replace bearings in a fleet of turbines that were less than 2 years old. Siemens talking about the loss said: “The charge is related to inspecting and replacing bearings due to the early degradation in certain turbine models. We believe this is related to recent batches of bearings and we are in discussions with the supplier” (see our post here).

Suzlon – aka Suzlon REPower, aka Senvion – have planted hundreds of its S88s all over the Australian countryside: in addition to those Infigen operate in NSW, Trustpower planted 47 at Snowtown, in South Australia’s Mid-North; and AGL speared a hundred or so into SA’s Mid-North, around Jamestown and Hallett.

To keep their workings lubricated and operating, wind turbine gearboxes have oil-reservoirs, like the sump in a car engine, and – like a car engine – the oil needs to be drained and changed on a regular basis.

At Woodlawn and Capital – the wind farms Australia’s former Treasurer, Joe Hockey rightly called “utterly offensive” – STT’s operatives informed us that the maintenance crew – charged with the job of changing the oil in Infigen’s Suzlon S88 turbines there – have found the task getting more difficult over time.

Apparently, the gearboxes are wearing out a whole lot faster than expected, with metal filings gumming up the oil-reservoirs; which has mechanics resorting to special efforts to first clear away the ground-up metal, in order to get the metal/oil mixture to drain out of the oil-reservoir.

Repairs, general maintenance, metal fatigue, wear and tear, blade and bearing failure all cost – and, together, help make intermittent, unreliable and intermittent wind power insanely expensive; and smash to bits the wind industry’s nauseating falsehood about wind power being “free”.

As noted, wind farm operating costs are typically in the range of $25 per MWh dispatched to the grid.  And due to the need for repairs to blades, gearboxes, generators, cooling systems, etc – or wholesale replacement thereof – that cost naturally increases over the life of the turbines used.

In its P&L Statement for 2013 (click here for the pdf) Infigen set out the financial “performance” of its American and Australian operations. From page 26, here’s Table 16 relating to its Australian operations, where it reports “Operating Cost (A$/MWh) as $23.93 for 2012/13 compared to an “Average Price” of electricity sold of $96.57 per MWh.

From page 29, here’s Table 20 where, on total operating costs of $36.3 million, $17.2 million is attributed to “Turbine O&M” (ie operation and maintenance); $0.9 million to “Balance of plant”; and $7.5 million to “Other direct costs”. Infigen’s US operations reported similar operating costs of US$24.18 per MWh for 2012/13 (refer to Infigen’s report at page 20 and Table 15 on page 24).

In 2015, Infigen’s financials told much the same tale (and, ironically, included a veiled curse on the Wind Gods for its falling revenues):

Bear in mind that wind farm operating costs of $24-25 per MWh compare with the ability of Victorian coal fired power generators to profitably deliver power to the grid at less than $25 per MWh.

The bulk of wind farm operating costs are taken up by maintenance and repairs: see Table 20 above (and see our post here for more detail).

Although some ‘repairs’ are more costly than others – if a ‘repair’ is possible, that is.

In this post we reported on a cluster of Suzlon S88s at a wind farm in Nicaragua that burst into flames and threw their blades to the four-winds – after which, one of them collapsed and hit the deck – all in spectacular fashion: the cause was said to be a “failure in their emergency braking systems”.

Then there’s the cost of a more mundane class of ‘repairs’.

The pictures below are of the bits and worn out pieces of Suzlon S88s taken at Suzlon’s yard in Jamestown, South Australia.

The picture above is of the gearbox assembly of a Suzlon S88 that literally ground itself to a halt at (what was then) AGL’s Hallett 2 wind farm in SA. The main ring-gear in the planetary section split into multiple pieces, destroyed the housing and sent about 250 litres of gear oil – contained in the housing – raining down the inside of the tower.

The turbine in question was out of action for over 3 months: the replacement was under warranty, meaning Suzlon was liable to stump up for the cost of doing so. That it took so long is no wonder, as Suzlon – which suffered India’s biggest convertible-bond default in 2012 – was seriously struggling then and isn’t in any better shape now – even a name change to “Senvion” didn’t help.

As well as the gearbox self-destruction episode at Hallett 2, the 34 Suzlon’s S88s used there suffered a raft of generator failures, all requiring complete replacements.

The photo above is of 4 ‘worn out’ generator assemblies from Hallett 2’s S88s that were replaced some time ago. The photo below is of a suite of new generator assemblies lined up to ready to replace other failed or failing S88 generators.

The gearbox and generator failures in Suzlon’s S88s at Hallett 2 (a wind farm that only started operating in June 2009), stand alongside what was the wholesale replacement of blades at the Hallett 1 (Brown Hill) wind farm south of Jamestown. There, 45 Suzlon S88s were used; commencing operation in April 2008. Not long into their operation, stress fractures began appearing in the 44m long blades; Suzlon claimed that there was a “design fault” and was forced by AGL to replace the blades on all 45 turbines, under warranty.

The photos below show the stubs from those blades outside Suzlon’s Jamestown workshop. The main bodies of the blades were ground up and mixed with concrete used in the bases of other turbines erected later (the plastics in the blade are highly toxic, and contain Bisphenol A, which is so dangerous to health that the European Union and Canada have banned it):

So, there you have it: the answer to the question of how long wind turbines last.

Which is about 10 to 12 years or until the subsidies run out, whichever occurs first. Or sooner still if they spontaneously combust!!