“Green Energy” sounds so neat. And windmills produce green energy. Who could be against green energy, and thus who could be against windmills? Most people assume that energy produced without carbon emissions also ends up lowering emissions overall. In spite of the intuitive sense that it must, does it really do so? As it turns out there are very good reasons why the overall savings are either negligible or even non-existent, and this series of posts goes into more details why that may be so. There’s quite a controversy within the field about this, a controversy that could be settled by doing actual measurements of emissions on a real grid before and after the implementation of wind. Unfortunately such a study has never been published anywhere in the world, which should give us cause to wonder why not.
What is left out of the above intuition are two underlying assumptions, both involving the effects of wind energy on the present generating facilities. The first of these assumptions is that the reduction in production from current fossil facilities leads to a proportionate reduction in emissions. The second is that the characteristics of wind don’t adversely affect the operation of the current fossil facilities. Neither of these assumptions is true.
For the first one, most current generation facilities are designed to run most efficiently at higher levels of production. Almost universally, the emissions increase as the production and efficiency fall. For the second one, wind production fluctuates by a surprisingly large amount (the cube of the wind speed), to the point where the remaining generators in the system must work harder to balance it. This increases emissions by a surprisingly large amount, to the point where it isn’t clear that wind by itself prevents any emissions at all. I go into far more details in my emissions details posting.
Proponents point to a list of benefits for wind energy – like emissions savings, jobs, energy security, saving imports and so on. By far the most important of these is emissions savings – is the reduction of greenhouse gases in the atmosphere. The other benefits are largely nonsensical or way overblown. As an example, very little oil is used to produce electricity, so how could wind turbines reduce that in any meaningful fashion? Even the claim of burning less fuel of any type is overblown, as shown by this small study, with more evidence contained in this larger study. And just so I’m not lumped in with all the “Gore-world-domination-agenda 21-conspiracy” true believers, I think the risk (not 100% sure of the reality) of global warming is real, and we should be doing everything reasonable to cut our emissions.
In light of the importance of this topic I’ve been surprised at how difficult it has been to find a paper that documents actual CO2 savings. You would think that before continuing to spend billions of dollars on a new technology that someone would take the time to see if it really worked as advertised. Amazingly, you’d be wrong. The only way that I know of to see if wind turbines work is for probably a government to measure a country’s emissions before and after the advent of the wind turbines, factor out all the other changes going on, and see if there’s been any improvement that can be reasonably attributed to the wind turbines. That such a study does not exist (after looking for over a year) tells me that either: (1) the government is already convinced, based on nothing more than faith, (2) the government is too stupid to even ask the question, (3) the government doesn’t care, or (4) they’ve done the study and don’t like the results. None of these strike me as valid excuses; we deserve better from our public servants. Canada’s case is typical, it seems they may not even have the ability to measure the CO2 emissions.
It is important to understand how all the numbers for the wind-industry and government claims regarding CO2 savings are obtained. They invariably use one of two basic techniques. The first of these is the “life cycle” method, where the total carbon emissions while making, installing, operating and disposing of a wind turbine are compared with a fossil (or nuclear, for that matter) fuel plant’s emissions. The second of these is what I call “direct displacement”, where each kw-hr generated by a wind turbine directly and entirely eliminates the emissions created during the generation of a kw-hr by fossil fuels. Both of these methods completely ignore the CO2 emissions that are necessarily created by maintaining a spinning reserve to back up wind’s fickle generation characteristics. The second method is more commonly used, so I’ll examine it in more detail, but the discussion below invalidates both methods.
Without exception proponents claim that every kw-hr of electricity that is generated by a wind turbine directly displaces a kw-hr generated by a fossil fuel plant, along with the emissions that would have been produced in that process. Here’s one example and and here’s another. If considering coal, which produces about 0.9kg of CO2 for each kw-hr generated, that much CO2 is assumed saved for each kw-hr produced by wind. Until quite recently (until slapped for truth-in-advertising violations), that’s exactly what the British wind industry was claiming. But in reality some combination of coal, gas, hydro and nuclear is used to generate electricity, so it makes more sense to calculate the average and use that figure. A typical result is about half of the coal number, approximately 0.5kg per kw-hr. As we dig further into the the real world, we’ll find that even this lower number is too high.
While the industry’s logic may at first seem intuitively correct, unfortunately intuition often does not equal truth. One of the main goals of the scientific method is to eliminate faulty intuitions, replacing them with the requirement to observe and measure whatever it is you are proposing, and then publishing your methodology and results so anyone can confirm (or not) your claims. It is intuitive that the world is flat – only by applying observations and measurements can the truth of a round world be demonstrated. In the case of wind turbines the industry’s emission savings intuition is undeniably false. The primary problem with wind energy (as well as solar) and CO2 savings is the inherent lack of control of its production, coupled with our lack of any way to store that energy on a utility scale. This leads to the necessity of building fossil-fired backup plants, as in Alberta or in Ontario, and/or running current fossil-fired plants at lower efficiencies. Both of these alternatives cause surprisingly large emissions, to the point where the savings very plausibly go negative. For those who are interested and/or need some evidence, please see my emissions saving details. But do not dismiss my arguments without even bothering to read my supporting details.
If you need someone with more gravitas than I, please at least read this recent article from Dr. Jay Apt – scientist and engineer (and yes, even astronaut!) – who now resides at Carnegie-Mellon. He’s got more gravitas than just about anyone in the field. His report summarizes the economic and political issues, but his background engineering facts are hard to dismiss. It is also saved here. It’s a well-written and very readable 10 pages.