I'm in Houston, TX again, this time for the Total Energy USA conference. I've posted previously regarding the Hess Tower (formerly the Discovery Tower but renamed when Hess Corporation (formerly Amerada Hess - yes, I know...)) leased the entire structure.
In my previous post, I expressed great skepticism regarding the ability of the vertical axis wind turbines (VAWTs) installed atop the tower to achieve the energy delivery claimed by the media and by the designers. As is my wont, I backed my opinion with some rough calculations. I concluded that they're basically a decorative greenwashing feature.
I don't know what, if any, energy production (really conversion, i.e., kinetic energy of wind to electrical energy - energy is never produced or consumed, it's only converted) has ever been achieved but when I looked at the tower on this visit, the VAWTs were conspicuous by their absence, as can be seen in the photo.
I wondered if they'd been too noisy, had broken down and been removed for repair, or what. Even if they produced no useful quantity of energy, they still looked cool (in my opinion) and removing them would not be particularly cheap or easy. But, as best I can determine from googling, a piece of one of the turbines apparently fell to the street (and possibly damaged a vehicle). Hess Corporation spokesperson Mari Pat Sexton states that the turbines have been "locked down" though, judging by the photo (taken by me two days ago) she must mean "locked down in the basement" or something because it's quite clear that they've been removed from their designed location. There are also, apparently no plans underway to replace the turbines.
I don't think that the loss of energy production will be of significance (I estimated that Hess would avoid a cost of something on the order of $1,500 per year). I'll estimate the amount of money wasted on purchasing the turbines and constructing the supporting structure.
It's been a struggle to find a price for the V3.5 turbines, but I managed to find a number here. Assuming the "rooftop" figure of $30,000, this works out to $8.57/watt of rated capacity. This is actually pretty low for such a small unit and I'd suspect that it's really higher, particularly given the estimates I made in my post about the VAWT in London. But I'll go with it, what the heck. Since 10 were in place, that makes the purchase price (excluding shipping and erection) $300,000.
I don't know if they used cranes or helicopters, but I'll assume the former and that they could erect lift and mount them in two days with four people. The total cost for crane rental and labor might be something like $10,000. Shipping might have been something like $12,000. This is pretty rough as I don't know the weight of the units.
As to the structure, using a cost per square foot of $40 (no tenant improvements, etc.) and an estimated 9,600 ft^2 of "structure" (it's the length of the building but quite thin and I've assumed two "floors" worth of structural construction) my estimate is that the structure cost was about $384,000. Thus, my estimate for the total installed cost is $706,000.
I actually suspect this to be low, particularly with respect to the structure, but it's probably in the "order of magnitude" ballpark. Add another $30,000 for removal, haul away, and disposal and we're pushing hard at three quarters of a million dollars. Pretty expensive for an exercise in greenwashing.