Comment by nine_k

I think we're on the same page. Lifting the actual computing devices would be not that expensive, compared to lifting a lot of other related mass, principally the cooling systems, and the solar panels.

The solar panels used in space are really lightweight, about 2 kg / m² [1], it's like ten times lighter weight than terrestrial panels. Still they need load-bearing scaffolding, and electrical conductors to actually collect the hundreds of kilowatts.

Water can't be made as lightweight though.

[1]: https://space.stackexchange.com/a/30238