Parasitic power and wind turbines. Sounds scary, but what’s the real story?

There are about 300,000 wind turbines generating economically sound electricity world-wide today. But some anti-wind lobbyists claim that wind turbines consume 50% or more of the electricity that they produce.

The claim appears to originate with Eric Rosenbloom, President of National Wind Watch [6] and creator of the wind disinformation site aweo.org site [1].  Among other claims, Mr. Rosenbloom says that wind turbines have massive heating bills to de-ice blades as well as lots of electricity consumption to start the blades spinning. Mr. Rosenbloom’s sources are an unnamed Swedish graduate student on a now defunct discussion forum and unlisted personal correspondence. Note that Mr. Rosenbloom’s credentials do not give any assurance of any technical or engineering background sufficient to make the claims he is making; he is a graphic designer and editor, running a small business in that field. [5] Other anti-wind advocacy sites reference Mr. Rosenbloom’s AWEO site uncritically and did not add any substantiation.

Max Rheese, Executive Director of two Australian organizations, the anti-wind Australian Environmental Foundation and the climate-denialist Australian Climate Science Coalition, likes to say that Australian wind turbines all have air-conditioning as his variant on the Eric Rosenbloom myth.[7] He lists absolutely no sources for his claims, but Mr. Rheese is known for his whoppers around wind energy. [8]

Note that these claims are unsubstantiated by anything that could be called evidence. They do not reference checkable sources, they do not show their calculations, and their claims are not assessed by independent bodies.

So what’s the real story? Do wind turbines suck up vast amounts of electricity from the grid to start and cool or heat themselves?  Or are they pumping out 99%+ net electricity with a trivial amount going to their operation?

Short Answer:

Mr. Rosenbloom, Mr. Rheese and other anti-wind campaigners who repeat the myth of low net generation are at best overly credulous and at worst lying through their teeth. De-icing is just starting to penetrate the market, air-conditioning doesn’t exist and published and reviewed lifecycle cost analyses (LCA) following ISO methodologies suggest that electrical consumption by wind towers is insignificant, so the ratio is extremely high.

Long Answer:

As always, breaking down the myth into its component parts is worth-while:

  1. De-icing systems
  2. Air-conditioning
  3. Blade start

Let’s take each in turn.

De-icing systems are just now showing up on wind turbines

In some northern climes in the winter time, ice does build up on wind turbine blades. This can reduce aerodynamic efficiency of the blades by a few percent.

Mr. Rosenbloom, originator of the de-icing myth, made his claims between 2006 and 2009.

Let’s read a quote from a wind industry journal from February 2012. [9]

Among the highlights during the first day at Winterwind 2012 was a stage presentation of de-icing solutions by six of the world’s leading manufacturers. Five of these systems are brand new and some have yet to enter the commercial market.

Two years ago this session would have been unthinkable, the market just wasn’t there, says Göran Ronsten, program coordinator of Winterwind 2012.

The total number of orders for de-icing wind turbines referenced was under 1,000 and the total number working at that time was under 100. When de-icing is operating in wind turbines, it will be operating at a significant net gain for generation in harsh winters.

So, there are almost no de-icing systems on wind turbines operating today, and there weren’t any at all when Mr. Rosenbloom, who continues to promote this, first made his claim a few years ago.

There isn’t any air-conditioning on wind farms in Australia

According to Epuron spokesman Martin Poole, their wind turbines use simple radiators like those in cars to draw heat away from blades when they are operating and don’t air condition them at all. Consultation with several industry representatives confirmed that there are no known turbine designs in Australia that feature air conditioning.

There are cooling products for wind turbines, but they aren’t commonly used. Australia isn’t known for being a cool place, yet major wind farms don’t use cooling products.

Given that Mr. Rheese provides no sources at all for his claim and given his colourful relationship with the truth on both wind generation technology and global warming, it’s likely fair to say he made it up.

Modern wind turbines start by themselves

Old US wind turbine designs used to use the same electric generators as coal, nuclear and hydro plants use. These are synchronous generators, and required the mechanical input to be a specific RPM to drive the generator to produce electricity at the same frequency as the grid. As such, they require a significant input of energy, mechanical or electrical, to get them to the right speed before they can generate. A Vermont design in the less than 100 KW used this and they were erected around the USA in relatively small numbers  range 30-40 years ago. This device also had a feature of blades designed to work optimally in higher-winds so a very slender profile and no pitch control. As such, it wasn’t able to take advantage of the force of lower speed winds.

Denmark used asynchronous or induction generators from much earlier, and all utility-scale wind turbines have used them for 20 years or so. These motors don’t require the mechanical input to be at the right RPM, but can generate electricity at a range of RPMs, which they then manipulate to be the right frequency in a second step. Further, the blades change profile from the high-speed tip through the low-speed wider portion of the blade nearer the hub. The wider portion catches more wind and allows the greater torque at lower speeds to spin the blades. Pitch control, changing the angle of the blade to the wind, allows breaking and starting of the blades in different wind conditions without requiring significant electricity from the grid to start them moving.

Historically, the synchronous wind generators used to occasionally fail due to maintenance and continue to spin when there was no wind, drawing electricity from the grid to do so. This led to the remarkably persistent myths that wind turbines continue to need this, and that wind firms make the wind generators spin when there is no wind to give the illusion of effectiveness. Neither is true.

Full-lifecycle LCAs make it clear that energy usage is minimal

Wind turbine manufacturers have a vested interest in accurate full lifecycle cost assessments (LCA) and publish these.   To maintain ISO certification — a necessity for any manufacturer to sell to more than backyard hobbyists — LCAs are required to be published and available.  They must follow manufacturing standard ISO 14040-14043 approaches to costing.  They must be independently reviewed.  What is relevant from these LCAs is that every step of manufacturing, transport, construction, operation, maintenance and dis-assembly is captured and quantified.  Literally everything of any significance is measured and included in the calculations.

For the purposes of this, let’s look at one specific wind turbine LCA, for the Vesta 2.5MW onshore and offshore wind turbines. [2] As required, it has been created following ISO standards, published for anyone to read and reviewed by an accredited organization for accuracy.

As an example of the degree of rigour applied to this approach, here is the paragraph solely related to the cost of transport during maintenance and inspection activities:

It is estimated that inspection will be carried out four times a year per turbine. Three of these are assumed to be carried out by helicopter and the remaining one by boat. Inspection will also include about 2,400 km a year by car per turbine. Since no data for a helicopter is available, recalculated emission data from a mid-sized jet is used.

So what does this comprehensive, standards-based, reviewed LCA say about electrical consumption during operation?  Nothing. The amount of electricity consumed during startup is so trivial compared to generation that it isn’t worth mentioning. It is insignificant.

Other LCAs for other wind turbines tell exactly the same story. Wind turbines consume so little electricity to start up compared to their generation that it just isn’t noted.  It’s irrelevant.

Wind farm operators monitor this and net energy generation is 99.7%+

Hepburn Wind is a community wind farm in Australia. Its Founding Chair, Simon Holmes à Court, has confirmed that over the first 11 months of operation, the wind farm generated 320 times as much energy as it consumed from the grid.

Other forms of generation draw more electricity

All power stations draw power from the grid when they are not operating, and all draw power from their own generation when operating (known as parasitic or auxiliary load).

For coal-fired plants at least 20 years old, parasitic (i.e., on-site) power consumption can run as high as 7 to 10 percent of gross MVA generation. [11]

and

in combined cycle power plant (CCPP.) the auxiliary power consumption fall in the range of 2 to 5 % of actual generating capacity. [13]

Coal plants use 20 to 30 times more parasitic power than wind energy. Gas generation uses 7 to 17 times more electricity just to operate than wind energy.

And requirements for lower environmental impacts from fossil fuel plants are creating greater demands for auxiliary power, which is reducing the benefit of efficiency gains in other areas:

“The share of total plant auxiliary electrical power in the fleet of fossil-fuel steam plants has been increasing due to these main factors:
−− Addition of anti-pollution devices such as precipitators and sulfur dioxide scrubbers which restrict stack flow and require in-plant electric drive power. About 40 percent of the cost of building a new coal plant is spent on pollution controls, and they use up about 5 percent of gross power generated (Masters, 2004).
−− Additional cooling water pumping demands to satisfy environmental thermal discharge rules.
−− A trend away from mechanical (e.g. condensing steam turbine) drives toward electrical motors as the prime mover for in-plant auxiliary pump and fan drives. [12]

Net losses from transmission are low

Screen Shot 2014-01-03 at 10.26.58 PM

Along with the average 7% auxiliary power draw from generation plants — which is declining with each MW of wind energy and solar that is put on the grid –, the transmission loss of 2.7% is very instructive. Long range transmission of electricity is much more efficient than typically presumed. Distribution losses outweigh it greatly, but still the combined loss of transmission and distribution is only 7.4%. And this is in a large country, so distances are great.

Here is a useful summary diagram of the comparative results of wind energy with the average grid mix of generation sources. [3]

Don’t believe anti-wind lobbyists

There are about 300,000 wind turbines producing clean, safe electricity world wide right now for a reason: it makes economic sense. Wind farms use a minuscule amount of energy from the grid compared to the amount that they generate. In fact, wind farms use much less electricity than standard generation plants. Anti-wind lobbyists such as Mr. Rosenbloom and Mr. Rheese literally make up disinformation to spread.

References:

[1] http://www.aweo.org/windconsumption.html
[2] http://www.vestas.com/en/about-vestas/sustainability/wind-turbines-and-the-environment/life-cycle-assessment-%28lca%29.aspx
[3] http://www.lcacenter.org/LCAX/presentations-final/220.pdf
[4] http://www.rpi.edu/cfes/news-and-events/Wind%20Workshop/An%20Environmental%20Life%20Cycle%20Analysis%20of%20Wind%20Power.pdf
[5] http://www.kirbymountain.com/index.html
[6] http://www.wind-watch.org/
[7] http://www.abc.net.au/radionational/programs/counterpoint/against-the-wind/2952948
[
8] http://reneweconomy.com.au/2012/fourteen-wind-energy-myths-debunked-97695
[
9] http://www.winterwind.se/the-ice-issue/

[10] http://www.tai.org.au/content/power-down

[11] http://www.elp.com/…/utilities-can-improve-power-plant…

[12] http://www05.abb.com/…/Energy%20Efficiency%20for…

[13] http://ac.els-cdn.com/…/1-s2.0-S1877705813001082-main…

4 comments

  1. Glen Estill · · Reply

    The first turbine I erected in Ferndale, a Vestas V80, consumed about 20,000 kWh/year but produced 5,000,000 kWh. All forms of generation consume some power. Nuclear plants consume up to 10% of what they produce for lights, control rooms, computers, pumps, compressors, etc. Coal plants have augers, pulverizers, pumps, computers, control rooms etc. Even photovoltaic has inverters that consume power. A wind turbine that consumes more power than it produces is called a fan.

    1. Thanks for the insights Glen. It’s very true that every form of generation has parasitic power losses. Wind farms are not unusual and the amount of parasitic power is minuscule.

  2. […] kg of cable to operating height and what the net energy output impact will be. For context, one conventional wind farm’s draw from the grid for blade start and other peripheral items was 1:320th of the […]

  3. […] kg of cable to operating height and what the net energy output impact will be. For context, one conventional wind farm’s draw from the grid for blade start and other peripheral items was 1:320th of the […]

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