This was the response I got from support back in early July.
There basic plan is to have N base Z1s tied together with a new controller unit. Remember from the photos we've seen and have been told about support and maintenance the controller unit on the top comes off leaving the bottom of the unit (which seems to be what stacks in the marketing photos) intact.
You will be able to upgrade the Z1. The additional controller will have hookups to allow for that power conversion from 110 to 220.
We will have options for buying that controller later.
Some of the details on it are still in development and as we have these fully formed, we'll get that info out there for our customers.
There basic plan is to have N base Z1s tied together with a new controller unit. Remember from the photos we've seen and have been told about support and maintenance the controller unit on the top comes off leaving the bottom of the unit (which seems to be what stacks in the marketing photos) intact.