Good comments...thanks for passing those along. I’ve had many discussions about this topic over the years and at some point early on when some assertion or other has been made, I end up saying something along the lines of “well... that all depends on where you want to draw the box around this issue. What’s in and what’s out?” Your response highlights exactly that.... since it’s complicated if the full picture is examined, it will almost always be the case that those who have been persuaded by the benefits of wind power, don’t look any further than the IWT itself.... and sheesh, they don’t even look that far or they’d have to face the fact that these things really are bird and bat choppers!
When one takes a look at the big picture of wind and solar and draw that box large enough that it needs to address all the upstream, downstream and sideways considerations, it becomes quite apparent just how bad IWTs and solar are as an electrical generator for grid level projects. If ever there was a case where one thing can have impact on an endless number of other things (even the seemingly unrelated things), it’s wind and solar. Here’s one example.... a typical 3 MW IWT has a concrete base under it that in most areas will need to be in the range of 1,000 tons. For every pound of cement, approximately one pound of CO2 is released into the environment. If the IWT is being sold as a CO2 displacing energy source, how long does it need to be displacing coal or natural gas to ‘payback’ just the amount of CO2 released during the manufacturing process for the cement that was used for its base? That’s not that hard a calculation .... but do unintended consequences like this ever get raised by the wild eyed advocates who have drawn their box so tight that this is excluded from the discussion? It’s because of this myopic thinking that the issue of gas turbine efficiency (which is crucial to the whole discussion of wind and solar) is never remotely on the radar.
I’m oft reminded of an endless number of things from my youth that are examples of cases where the initial decision and cost for it have nothing to do with the impact or the cost of maintaining that thing.... It’s like having no job but being given a free truck that only gets 5 miles per gallon. In the end, it doesn’t work....More recently, I was asked to evaluate a process that wanted to make a change that would have involved a horrid amount of compressed air. Early on, I asked the question of whether anyone had bothered to calculate for comparative purposes, the cost of generating the compressed air and how efficient that was compared to what they were doing now? And did the plant even have an electrical system that could handle the capacity of an additional 10,000 kW? At that point, things went quite silent....
The same sorts of questions arise when folks talk about the ‘electrification of cities’ and the use of electric cars in cities to reduce smog and so they can be ‘green’.... well, that electricity has to be generated somewhere.... so how is that going to happen and what is the big picture impact of that for the environment and people where it happens and everywhere in between where the electricity is generated and where it’s used? The first thing I tell people is we’re going to make that box big enough that it takes in the whole universe and then we’ll keep reducing the size of it so that decisions can be made at each step of that reduction process of how important that thing is that no one wants to include and more importantly, for whom?
I believe that you have hit upon the REAL inconvenient truth.
BTW, being a Civil Engineer by education, when I first entered the petroleum business I did the wind load and overturning moment calculations on commonly used large field oil treating vessels. Under normal conditions the footings were not large enough to prevent them from being blown over. Sufficient footings were so far out of the box and the convention had survived with few enough problems pressing on was not worth the effort. Thus, guy wires and lots of connected pipe work prevented toppling. So it goes.
Point being made is, soil failure in foundations resulting in toppling is cumulative. In some conditions many of these conventionally designed structures will topple. The bigger ones will be interesting. I see they are using a lot of suction pile anchors in the offshore installations. We never used them for extended periods of time that I am aware of, just for temporary mooring anchors.
There sure is a lot of concrete and steel in the foundations for these things already. I’m sure all loads are being taken into account.