miller60 writes: HP Labs is developing a concept for a "net zero" data center — a facility that combines on-site solar power, fresh air cooling and advanced workload scheduling to operate with no net energy from the utility grid. HP is testing its ideas in a small data center in Palo Alto with a 134kW solar array and four ProLiant servers. The proof-of-concept confronts challenges often seen in solar implementations, including the array’s modest capacity and a limited window of generation hours – namely, when the sun shines. HP's approach focuses on boosting server utilization, juggling critical and non-critical loads, and making the most of every hour of solar generation. Can this concept work at scale?