Some planning applications can be given the go ahead if the perceived "benefits" outweigh negative impacts from a development or deviation from local or national planning policies. An obvious one is the Trump development at Menie where it was recognised that the "benefits" from the project would outweigh the detrimental effects on the environment. More recently the Coul Links golf proposal wasn't given the go ahead as it was felt the socio-economic benefits would not outweigh the environmental impacts from that particular development.
Obviously this battery farm is a different scale, policies etc but it wouldn't be that unusual if it were given the go ahead despite contradicting the IMLDP for example but the applicant would need to provide a robust argument that the departure is acceptable.
I would surmise that this is not the case here and, as @Stephen Malkmus has mentioned, this is what you end up with if you hire some jobbers to prepare your application material instead of getting experts involved.
Of course if HC do refuse the application there is the option of an appeal to the DPEA but that's not guaranteed to overturn the decision and if the DPEA were to uphold the original recommendation of refusal it would leave ILI in an almost impossible situation to move forward other than to submit a completely new application.