I'm not familiar with the Schneider offering in the field but similar prefabricated metal substations are not uncommon in renewables, often as part of an inverter skid.

They are generally far more compact and the reduction of site work does make life a lot easier; installation and commissioning can potentially be very quick. On the other hand this compactness makes any additions or future modification more difficult. Consider for example that transformers have gotten larger in recent years owing to increased efficiency expectations.

Because you're buying a product more-or-less off the peg you've got much fewer options for customisation, and the design is often for an international market, which may not always suit your existing practices or requirements. For example I've lost count of the amount of times I've had to talk to suppliers about redundant bonding points for MV equipment, and am currently engaged in prolonged discussions with another just to have a slightly nicer relay to drive some automation.

Make sure maintenance and repair work has been considered in the design, both of the substation itself and the location it will be installed in.

Metalclad buildings generally do not perform as well thermally, so particularly if you have low load in winter you might need additional anti-condensation measures which could add to running costs, and the enclosure does require active maintenance.

My main concern was the enclosure and also the practicalities of maintenance, i.e. being exposed to the elements rather than being protected by an external structure.

We have been assured that the enclosure itself is suitable for marine environments, constructed of stainless steel and powder coated...but I'm also aware of the damage our coastal environment has caused to other assets.

Thank you for your insight.