Yup I think I missed a comma when originally reading the sustainability report. They buy-in an average of 747 MWh a day (2022).
The point I was stumbling to try and make was that Heathrow is dense. Just under a GWh a day delivered to a 1200ha site isn't going to get a natural diversity of supply, especially compared to a rail system does.
[0] suggests (without a useful link and my searching has not found one) that Heathrow is doing 460GWh annually. Presumably[1] that equates to 1.25GWh daily (which could be where the 1-2MWh/day came from - a simple unit error)?
