Wind Farms Do Not Reduce Emissions: De-Bunking The Myths

There are many arguments put forward to show that wind turbines do not reduce carbon emissions. I plan to write a lengthy piece at The Energy Collective at some point explaining the flaws in these arguments. But there is one I feel like debunking now.

This myth is particularly favoured by the Global Warming Policy Foundation, and is sometimes put forward by people who should know better.

Here is how it goes.

Each gigawatt of wind power must be backed up by 1 GW of relatively inefficient OCGT gas power plants. Wind turbines however only run with around 25% capacity factors. Therefore you need to run the OCGT power plants at 75% capacity factors.

In CO2 terms this is a bad idea, and no better than just getting your electricity from CCGT power plants. OCGT plants give you 0.6 tonnes of CO2 per MWh, whereas CCGT plants give you 0.4 tonnes of CO2. So wind backed up with OCGT will give you (0.75*0.6)/(0.4) = 1.125 times more CO2 than a purely CCGT set up.

Wind farms then provide more than 10% more CO2 than you would get if you just stuck with gas! Why bother?

Well, the logic above sounds persuasive and probably would persuade the average person with a prejudice against wind turbines. It is also total nonsense.

There are many engineering reasons why it is nonsense. I could go into them, but it can be refuted a little more simply.

The UK now has over 10 GW of wind power. By the above logic it therefore requires at least 10 GW of OCGT power plants to provide back up to these wind farms. If it does not then the arguments are complete piffle.

Thankfully the UK government provides us with a full list of power plants in Britain. So we can easily check how much OCGT is available to back up wind farms.

Instead of 10 GW of OCGT the UK has a total of 1.3 GW of OCGT. Not exactly an insignificant discrepancy.

Currently the UK has almost 11 GW of wind capacity, but only 1.3 GW of OCGT to back it up. And I can find absolutely no evidence of efforts to procure significant amounts of OCGT to back up wind farms. The argument then is bunk.

But these myths persist, and may go one persisting.

More gibberish about wind turbines

The belief that wind turbines do not reduce emissions appears to be incapable of dying. Humans however are rather fond of myths, so don’t expect an imminent death.

So, the Irish Times this week reports the usual gibberish from the usual quarters. Wind farms require extra spinning reserve etc. etc. and so they do not reduce CO2 emissions.

I’ve explained why this is gibberish before, so will not do it again.

But it should be easy to prove that wind farms do not reduce emissions in Ireland. It now gets over 15% of its electricity from wind turbines, hardly an insignificant figures. Statistics are readily available for how much natural gas, coal, and in Ireland’s case peat, is used to generate electricity. These statistics can then be analysed to see if the fuel consumption of conventional power plants is consistent with wind turbines reducing emissions or not. If wind turbines don’t reduce emissions, as people claim, then these power plants should be consuming far more fuel per unit of electricity than expected. And this can be tested quite easily.

So why have wind farm opponents not got hold of this data to prove that wind farms do nothing to reduce emissions? I can guess the answer.

Paradox of the day: Jevons’ Paradox

New EU rules are going to make transport greener according to a report in Business Green today. Maybe, or maybe not.

But I was struck by the following sentence:

“The Commission said that for a long distance lorry covering 100,000km a year the changes would cut fuel costs by €5,000 a year and reduce greenhouse gas emissions by 7.8 tonnes.”

Can anyone spot the problem? If not you should acquaint yourself with the views of this man, Stanley Jevons:

As Jevons remarked “It is a confusion of ideas to suppose that the economical use of fuel is equivalent to diminished consumption. The very contrary is the truth.”

Tomato, Tomato; Percentage, Degree

Christopher Booker is one of the UK’s leading climate change “skeptic” pundits. Here he is this week displaying his rigorous grasp of the issues:

When future generations come to look back on the alarm over global warming that seized the world towards the end of the 20th century, much will puzzle them as to how such a scare could have arisen. They will wonder why there was such a panic over a 0.4 per cent rise in global temperatures between 1975 and 1998, when similar rises between 1860 and 1880 and 1910 and 1940 had given no cause for concern.

I might suggest that not knowing the difference between percentages and degrees celsius might indicate a poor understanding of the issues, but in the case of Booker such things are redundant.


Why The IPCC Is Wrong About Bio-Energy

So, the IPCC has released their report on climate change mitigation. Naturally various people are in spin-mode. Greenpeace’s “journalism” wing have “15 key findings from the IPCC mitigation report.” Unsurprisingly the findings that do not suit Greenpeace’s agenda are not key.

And some journalists are doing a woeful job in doing their job. Damian Carrington of the Guardian tells us that the IPCC have concluded that mitigating climate change is “eminently affordable.” Meanwhile in a separate story the Guardian reports the IPCC telling Mr. Carrington that they are not allowed to make such conclusions.

But instead of hectoring journalists and complaining about the inevitable platitudes doled out in response to this report, I will instead suggest that the IPCC needs a good kick up the arse.

Consider what they say about bio-energy in the summary for policy-makers.

The table on page 18 informs us that if we only use a “limited” amount of “modern” bio-energy then the costs of keeping things to 450 ppm CO2-equivalent will increase by 64%. This 64% is a median figure, the range is from 44-78%.

So, they are expressing reasonably high confidence that restricting ourselves to “limited” bio-energy will make things much more expensive.

However their definition of “limited” bio-energy is rather absurd, hence my suggestion that they need a kick up the arse.

What is limited? 100 EJ of “modern” bio-energy per year. For context we consume around 450 EJ of fossil fuels each year. So “limited” bio-energy means that we will get the equivalent of 20% of current global primary energy consumption from “modern” bio-energy.

This is not “limited” in any sense, and it is easy to see why.

100 EJ per year corresponds to an average power of around 3.2 TW, that is 3.2 trillion watts. How much land would we need for this to come from bio-energy? Well, a lot.

Typical bio-energy plantations provide a power density of less than 0.5 watts per square metre, and this is after significant fossil fuel inputs through nitrogen based fertilizers etc.

So to get 3.2 TW from bio-energy we will need something like 6 million square kilometres of land to be converted to bio-energy plantation. This is roughly two times larger than India. Of course with a bit of genetic engineering and good luck perhaps we could shove this down to 3 million square kilometres. But a land mass the size of India is not “limited” by any definition.

According to the FAO total global arable land is 14 million square kilometres, just over two times bigger than the land we might need to get “limited” amounts of energy from bio-energy. It already appears to be the case that existing biofuels have put vast pressures on land use, and are resulting in significant increases in food prices. Just imagine what a few million square kilometres of arable land being converted over to biofuel plantation might do.

Of course some of this bio-energy could come from forest plantations. The IPCC maybe have bio-coke in mind, so that we can continue making over a billion tonnes of primary steel each year without needing over half a billion tonnes of coal.

How much forest plantation do we currently have? In 2005 it was just over 1.4 million square kilometres. Converting all of this over to biomass plantation would provide us with around a quarter of this “limited” bio-energy. Perhaps we could just convert the whole of the Amazon rainforest over to biomass plantation, it is only 5.5 million square kilometres.

So if we want “cheaper” mitigation we will need to convert perhaps well in excess of 6 million square kilometres of land over to bio-energy plantation. Does the IPCC really believe this is credible?


A tripling of renewable energy?

The Observer and the BBC are both reporting that the IPCC today will call for a “tripling” of renewable energy to “avert climate disaster.” 

Both reports are classic examples of how badly numbers are reported. What do they mean by renewable energy? Does this include hydro-electricity and biomass? A rather necessary distinction.

When should this tripling occur by? 2030, 2050? This is not stated.

But let’s say we tripled renewable energy, including hydro, by 2030. By itself this is highly unlikely to stop carbon dioxide emissions being higher in 2030 than they are today. Renewables, including hydro, are below 10% of global primary energy consumption currently. Tripling this is fine, but remember that total primary energy consumption increased by 30% in the last decade.

In fact in the last decade coal consumption alone increased by 1319 Mtoe. This is greater than the total consumption, not the increase, from all renewables. See how tripling renewables will not achieve as much as many think? As Hans Rosling has demonstrated most people think renewables deliver far more of our energy than it does.

The IPCC report is coming online shortly, evidently. And then I can find out what they really mean by a “tripling” of renewable energy. My guess is that they mean a tripling of the percentage of total energy consumption from renewables. Or at least I hope that’s what they mean.

Some things to read

It is time for me provide my somewhat irregular list of reading material.

A lot of people are now claiming that coal growth is coming to a halt in China. Mostly this is just a narrative set up to serve political ends, it serves to take some ammunition out of the hands of those favouring climate inaction. Greenpeace after all is the source of the recent claims, not a bunch of academics.

The key thing here is to recognise that China’s statistics are notoriously unreliable. If coal consumption only grew by around 2.5% you must first ask if the statistics are to be trusted. So I recommend reading this piece that shows that China’s coal consumption is unlikely to have grown by such a low amount given how much its economy, industrial output, steel production, and electricity production grew.

We now subsidise fossil fuels to the tune of half a trillion dollars a year, far more than renewable energy. Or so we are often told. This claim however does not survive much scrutiny. My go to deconstruction of fossil fuel “subsidies” is this piece by David Steven. I highly recommend it.

When it comes to energy few people are more worth listening to than Vaclav Smil. Here he is in discussion with Jeffrey Ball. If you want insight, not vacuity or wishful thinking, read Smil.

I have come rather late to reading Jonathan Meades, but his prose collection Museum Without Walls is one of the best things I have read in a long time on the built environment. Meades’ humanism, urbanism and dislike of all forms of bullshit is very potent when combined with his tight prose.

And here is something different. The Girl Hunt from the musical The Band Wagon, a remarkable piece of cinema first introduced to me when reading Clive James’s website





"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." -Richard Feynman


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