The sole justification offered for the offshore wind stampede is that we need to reduce CO2 emissions from electric power generation. A quick look at the numbers shows that this is a truly terrible idea. Here is a very simple gander at the likely costs and supposed benefits.
First let’s do what I call a “fantasy cost benefit analysis” for offshore wind emission reductions. It is a fantasy because it simply assumes (1) every MWh of wind generation eliminates a MWh of gas fired power and (2) there are no environmental costs or cost increases. We are isolating the simplest possible case
Mind you we are also going to use the so-called Social Cost of Carbon (SCC) to calculate the supposed benefits from the CO2 reduction. This SCC is also a fantasy but that is another issue.
As always we will use New Jersey’s wishful target of 11,000 MW of offshore wind capacity as our example. This is merely a convenient example as the the analyses are quite general.
The fantasy cost benefit calculation is deliberately simple, as follows. Let’s assume a constant 40% capacity factor and a generator life of 20 years, both of which are commonly used. There are 8,760 hours in a year so 40% of 20 years is roughly 70,000 hours. (I like simple numbers so do a lot of rounding off.)
Thus our 11,000 MW generates around 770,000,000 MWh over its lifetime. The standard gas fired CO2 emission factor is roughly 0.5 tons per MWh. (Note that this combines peakers and combined cycle plants which have very different emission factors, so it is sensitive to the local generation mix, which we ignore here.)
This gives us a fantasy total of 385,000,000 tons of CO2 of emissions avoided. Given our previously estimated direct cost of $100,000,000,000 we get a cost for avoided emissions of about $260 per ton.
The official Biden Administration SCC is just $51, making the offshore wind cost over five times the benefits for the fantasy case. Note that this SCC includes the mythical damages in the whole world. Damages in just America give a SCC of a mere $7/ton, in which case the costs are 37 times the benefits.
So even in the fantasy case the costs are at least four times the benefits, making offshore wind a very bad way to reduce emissions.
Not let’s consider a somewhat more realistic case, although we still ignore nasty stuff like environmental damage and the cost increases that are bound to occur. We simply take into account the fact that the CO2 reduction will be nowhere near a big as the fantasy case assumes. This fact is briefly explained in my article: https://www.cfact.org/2023/05/31/offshore-wind-may-not-reduce-co2-emissions/.
As explained in the article cited above, the intermittency of wind power greatly reduces the efficiency of the gas fired backup generators. That is, a lot more gas has to be burned to generate the same amount of electricity. This means that wind power will not reduce emissions by very much.
Let’s assume the CO2 reduction is only 20% of the fantasy case. This gives a cost per ton of $1300 which is roughly 26 times the global SCC benefits of $51 and a whopping 186 times the US $7.
Thus, assuming SCC is real, offshore wind is a terrible way to reduce CO2 emissions. The cost of offshore wind will be enormously greater than the benefits. A more complex analysis could, and should, be done but it would only make these bad numbers worse.
And of course SCC is itself a false claim. There is no evidence that our emissions are causing any real damage. In that case it is all cost with no benefits, so there is simply no possible justification for destructive offshore wind development.