Canada's green internet network added a rooftop solar powered datacenter as a node on its network that requires the use of self-renewing energy supplies. This announcement, which seems to have gotten very little attention, is more interesting in terms of the design idea behind the datacenter processing model than the use of solar power.
The eight solar panels will only generate 1840 watts of power, a far cry from the hundreds of kilowatts usually consumed by a datacenter. But the concept of the green network is that when a node runs out of stored power, it hands off its computing responsibilities to another node that is powered up and operational. The depleted node than recharges, and when power is restored, becomes an available datacenter node on the green network. This node is the first of five planned for the network and will be used to manipulate research data.
This is certainly a different take on the idea of distributed nodes for datacenter processing. The focus is on maintaining performance with renewable energy resources and at this point doesn't seem to address any other issue (such as the environmental issues of large scale solar cell production). In talking to datacenter designers, solar is definitely on the table but primarily as an alternate additional power source, not as a primary energy provider.
The academic aspect of the research network also doesn't concern itself with issues such as the security data passing between nodes, unexpected data interruption, powering the network itself, ad infinitum, but it does offer an interesting discussion point for the practicality of solar power for datacenters and this type of distributed datacenter node.