Wind energy reduces green house gas emissions

Despite the reality that wind farms are one of the most environmentally benign forms of generation going and their displacement of fossil fuels, many anti-wind lobbyists and campaigners are spreading a myth that they don’t actually help with global warming.

Sadly, James Lovelock who has done so much for the environment is among them in his most recent book and appearances.

As if this were not enough to damn wind energy, the construction of a 1 GW wind farm would use a quantity of concrete, 2 million tons, sufficient to build a town to 100,000 people living in 30,000 homes; making and using that quantity of concrete would release about 1 million tons of carbon dioxide into the air. – James Lovelock in The Revenge of Gaia

Lovelock isn’t alone. Others have chimed in as well:

Ramping the back-up gas plants up and down would mean running them very inefficiently, and give off so much CO2 that we could end up increasing our overall emissions rather than reducing them – Telegraph columnist Christopher Booker

A retired Dutch physicist gets far more press than he deserves for his flawed analyses which disagree with pretty much every professional grid management study:

A study in the Netherlands found that turning back-up gas power stations on and off to cover spells when there is little wind actually produces more carbon than a steady supply of energy from an efficient modern gas station. – retired physicist Dr C le Pair

Fox News comes out with its own extreme variant on this:

New Research Shows Wind Farms Cause Global Warming – Fox News headline

So what’s the story? Have anti-wind lobbyists finally found an argument that doesn’t fall apart as soon as anyone looks at it? Or is it another tissue of lies and disinformation?

Short Answer:

Wind farms reduce CO2e emissions in the overall electrical grid by substantial amounts. Typical grids produce 800 g of CO2e per KWh generated by their mixes and wind energy displaces virtually all of that. Claims related to concrete use are pure disinformation as is shown by apples-to-apples comparison of full-lifecycle comparisons of wind energy to other forms of generation. Implications that wind farms change weather and cause global warming are massive exaggerations from minute local effects.

Long Answer:

As always, it’s worth breaking the myth into its various components and popping each bubble one-by-one:

  1. Wind turbines require so much concrete that they produce far more CO2e than they can possible reduce
  2. Wind turbines require 100% fossil fuel backup and it is less efficient, so more CO2e is produced by backup than is saved by wind turbines
  3. Cycling of fossil fuel plants to support variability of renewables makes them so inefficient that any benefits are eliminated
  4. Wind turbines slow the wind, mix layers of the atmosphere and create global warming

Wind turbines including concrete bases have the lowest CO2e emissions of any form of generation

Concrete use is factored into the full lifecycle cost analyses (LCA) comparing various forms of generation. Manufacturing LCAs follow ISO standards, must be published and must be subjected to external independent auditing. Every manufacturer of anything bigger than a breadbox follows the same standard, regardless of what form of generation they are building and maintaining. The best available meta-analyses of all forms of generations’ lifecycle costs of energy show that wind energy has a full-lifecycle, CO2e emission lower than any other form of generation, lower even than nuclear, 1 / 50th of natural gas and 1 / 100th of coal. [2]

As for the amount of concrete in wind turbine bases, the best analogy is that a modern wind turbine of 2.5-3 MW in scale using straight concrete foundations uses the same amount of concrete as about 6 modern detached homes do for foundations, basement walls etc. A 250 square meter / 2,500 square foot home requires about 36 cubic meters of concrete, while a wind turbine foundation requires about 300 cubic meters. [3] Rock-anchor systems have seen 56 cubic meters of concrete used. Let’s call it an average of 6 homes equivalent concrete per wind turbine.

Modern wind turbines are typically in the 2-3 MW range, with much larger ones offshore and larger ones often considered for most wind farms. Assuming 2.5 MW average for a modern wind turbine, this would require about 400 wind turbines to enable a gigawatt of generation capacity, resulting in about 2,400 homes equivalent, not 30,000 homes worth, as Mr. Lovelock and others assert. If you scaled up for apartments, townhomes and bungalows, you might get to 6,000 homes, but nowhere near 30,000. The people who make this claim are grossly exaggerating the needed concrete without doing any research.

So not only do wind turbines not use unusual amounts of concrete, it is included in the apples-to-apples comparisons that show that with the concrete bases, wind energy is still enormously better than the alternatives.

Wind farms on the grid require a fraction of their capacity as backup, and the backup is often non-CO2e producing

Before we get into the details, what does actual grid management data show? Pretty much one-for-one replacement of fossil fuel generation with wind energy, meaning that CO2e is also displaced on a one-for-one basis.

According to major grid management studies in the UK and Finland, renewables at penetrations of up to 20% of demand will require only 20% of their capacity as backup and that backup can and will be from neighbouring jurisdictions’ excess capacity, whether from unused hydro capacity within jurisdictions and from already existing fossil fuel generation capacity that is maintained as backup instead of being decommissioned.

Picking apart the disinformation, no one suggests that wind energy provide 100% of grid demand, but that it makes sense in the range of 10-20% of grid demand for the majority of jurisdictions (outliers including Spain, Holland and one state in Australia). In that range, it requires about 4% maximum of demand as backup.

The second piece of disinformation is the assertion that coal or natural gas capacity has to be built to provide this backup capacity. As backup will come from existing nearby jurisdictions, unused hydro and existing generation capacity that is no longer used full-time, no new backup must be built in the vast majority of cases. [1] Natural gas plants are typically used for peaking supply now, which is exactly the same usage model needed for renewables backup; they often have capacity factors of 10% already. This doesn’t change anything about use of natural gas. Coal plants are never used for renewables backup because it takes hours to turn them up or down; thats why coal is used for base load power, not peak load power. Suggesting that coal is used for backup is just more disinformation.

 

Empirical evidence from the UK National Grid and the US NREL shows almost no impact on fossil fuel plant efficiency

These are the results of the “high” penetration scenario of the Sept 2013 released study from the US National Renewal Energy Lab where 16.5% each of wind and solar were providing total demand. Note that when 33% of energy is provided by renewables, total carbon savings are from 39-34% and other savings are equally significant.  Total fuel costs savings for supply were $7 billion compared to <$35 million for increased operating costs for fossil fuel generators, a net savings in costs of generation of about $7 BILLION DOLLARS. This study was based on emissions data from almost every generation facility in the USA, and reviewed by over 50 grid management and energy experts from utilities, research institutes, universities, manufacturers and generation firms across the USA. [10]

 

Perhaps a direct quote from the head of Energy Strategy for UK’s National Grid might be persuasive:

Dismissing this as one of the “flakier arguments” in the renewables debate, Smith points to arecent analysis National Grid undertook for the Scottish Parliament. It concluded that over an 18 month period, the expected emissions benefit of using wind power – that is the amount of carbon dioxide saved by using wind to produce power – was reduced by just 0.1 per cent as a result of the need to use fossil fuel power stations as backup.[8-9]

So wind energy requires a fraction of its capacity as backup and that backup won’t be creating nearly as much CO2e as critics claim. Busted and busted.

Wind turbines can make minor changes to local weather, not the climate

Liming Zhou, associate professor at the State University of New York, Albany published a paper [4] on April 29 in Nature Climate Change which found that ground temperatures directly beneath three wind farms in Texas were an average of 0.72 degrees warmer. The diagram below is from his paper showing an enhanced view of this increase in ground temperature.

First, the facts.

  • Mr. Zhou did publish a paper which found localized warming under wind farms in Texas at night. This was an average of 0.72 degrees.
  • It is highly localized. There is no spread of this warming beyond the immediate locales of the wind farm.
  • There is no observable impact on local flora or fauna.
  • There is no connection to drought in Texas.
  • The study only looked at 2003-2011 data. I quote: “satellite data for the period of 2003–2011 over a region in west-central Texas”.

Now the hype, in which Mr. Zhou appeared fully complicit although he’s since recanted.

  • Mr. Zhou asserted in his paper that: “Our results show a significant warming trend of up to 0.72 °C per decade.” As his data only covers 9 years, it is impossible for him to assert a warming trend per decade.
  • Mr. Zhou also says “These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate.” What he doesn’t say is that this would require wind turbines everywhere. And what he also doesn’t say is that this degree of wind energy would supplant all fossil fuel generation within a radius of about a 1000 miles with its attendant waste-heat and warming C02 emissions. The net impact would undoubtedly be highly positive. While AGW is strongly supported by evidence, Mr. Zhou is speculating.

To his credit, at no time did Mr. Zhou say wind turbines would have a larger climatic impact. This was left to Fox News and various other news sources that should have known better, but couldn’t resist the headline.

This has become fodder for a long-running myth that has been dismissed by everybody who doesn’t hate wind energy. [5], [6], [7] Only global-warming denying news outlets and anti-wind lobbyists still pretend this is true. It’s part of their habit of throwing everything and the kitchen sink at wind turbines instead of having a rational conversation about siting and intelligent setbacks.

Summary:

Wind farms not helping with global warming — in fact causing more green house gases to be emitted — is a multi-headed hydra of a myth. As can be seen, each head of the hydra is as mythical as the last. It is kept alive only on anti-wind disinformation sites and by global warming denial journalists and ‘news’ outlets.

References:

[1] How much backup does a wind farm require? How does that compare to conventional generation?
[2] http://en.openei.org/apps/LCA/
[3] http://www.alternet.org/story/61523/big_houses_are_not_green%3A_america’s_mcmansion_problem?page=0%2C1
[4] http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1505.html
[5] http://switchboard.nrdc.org/blogs/ssuccar/does_wind_energy_really_cause.html#_login
[6] http://www.nasa.gov/topics/earth/features/tx-wind-farm.html
[7] http://www.npr.org/2012/04/29/151646558/if-a-fact-dies-in-the-forest-will-anyone-believe-it
[
8] http://www.carbonbrief.org/blog/2013/03/interview-with-the-national-grid
[
9] http://www.scottish.parliament.uk/S4_EconomyEnergyandTourismCommittee/NATIONAL_GRID.pdf

[10] http://www.nrel.gov/electricity/transmission/western_wind.html

2 comments

  1. […] existing coal generation once societal costs are calculated in. And with coal seam gas producing 50 times the CO2e on its full lifecycle as wind energy, the question should be how little gas generation we can get […]

  2. […] existing coal generation once societal costs are calculated in. And with coal seam gas producing 50 times the CO2e on its full lifecycle as wind energy, the question should be how little gas generation we can get […]

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