(3 years ago)
Public Bill CommitteesQ
Richard Hall: On those two specific projects, Heathrow and Thames Tideway, I cannot give any insight. I am not particularly close to those individual cases. It is fair to note that in both cases the cost of capital brought forward by the model seems to have been low, in particular in the case of Thames Tideway. On nuclear, I simply go back to the point that there is a large base of literature looking at historical cost overruns and the extent to which things come in on budget. That tends to display fairly consistently that these types of projects are very likely to be subject to optimism bias at the time that they are procured—a belief that they will be cheaper than they actually will be.
In addition to the costs and dates I mentioned from the BEIS impact assessment suggesting the average levels of cost overruns, look at a couple of other examples from academia: Sovacool et al. looked at a global example of 180 new nuclear plants and found that 97% of them came in over budget and that the average cost overrun was 117%; and Flyvbjerg et al. found that in a sample of 194 nuclear plants, the median cost overrun was 68% and the median schedule or construction-time overrun was 40%. That is a fairly large sample set of projects, and the analysis tends to suggest considerable optimism bias for new nuclear—it tends to come in late and over budget.