But does that count as a sufficiently firm order for the purposes of your remarks? Has National Grid been sitting on it for 2.5 years without responding?
It books your place in the connections queue. Network operators like National Grid are required to be completely impartial about providing connections, so each project must wait its turn.
Normally, the customer (Network Rail) specifies what they want (i.e. voltage, power, security of supply requirements etc.) and then the network operator (NGET in this case) come back with the connection offer (cost & timescale).
As I understand it, Network Rail specify a 25 kV single phase point of connection. This means National Grid are responsible for the design and construction of all aspects of the 400/25 kV substation.
Once a customer accepts the offer and pays the connection fee, then the network operator will design, plan and build the connection point.
If the customer does not accept the offer within the time limit, then the offer lapses, the customer loses their place in the queue, and would need to reapply (and rejoin at the back of the queue).
The point about grid supply is that it is likely to be the longest lead item and so part/all of the critical path
I find it a bit difficult to believe that NR was merrily rebuilding road bridges in the area in 2015 without having thought about the grid connection, so expect that a connection was originally sought in 2011/12-ish when it became clear that the project was likely to be authorised.
However, with the pause in 2015, and subsequent delays, NR may have repeatedly deferred their "go live" date (which would explain why nothing has been built).
Deferral would have kept the Programme's place in the connection queue.
Alternatively, after 2017 (Grayling), the connection request may have been withdrawn or allowed to lapse. In this case MMLE would need to reapply join the back of the connection queue. This new application would presumably have been around 2021 when the IRP re-committed the programme.
HS2 would have complicated the design
Although if HS2 Ltd were a separate applicant for the original HS2 2b via Toton, it would really be National Grid's problem to solve.
Post-IRP, there may have been a lot of abortive cost to redesign for Phase 2b joining the MML at more or less the expected location of the substation.
