Determination of 2 year energy consumption

It is impossible to say for sure. This purchase is typically based on the energy modeling results. Even if it overestimates the initial energy use it is the conservative approach. Anything else would require some significant level of justification.

As I said it is impossible to tell without seeing the calculation. Even then you will still be relying on trying to convince an individual reviewer with the inherit potential variability of an individual's opinion. I am not aware of any precedent for what you would be submitting. You would be asking to buy less than is required. The energy model is already a rough estimate. Roll out strategies change over time. There are numerous additional variables you would be introducing to the determination of what is acceptable. My initial impression without seeing the calculations is - no you can't justify buying less because the facility will not be fully fitted out initially. The calculations require you to do the EAp2 calculations with a full fit out. The EAc6 calculations require you to buy 35% of that total. So I think it would be very difficult if not impossible to justify buying less because it goes counter to the requirements. That said you certainly can try. If you do i would be prepared to increase your green power purchase if your justification is not accepted.

Surely you could run the energy model for say four years or whatever and stage in the equipment and loads as required?