This chart shows an approach developed by HP to schedule critical and non-critical workloads to maximize solar power generation during daytime hours. The power capacity from one afternoon hour is reserved to offset power used to run critical workloads during overnight hours. (Source: HP Labs)
Can existing strategies be combined to create a "net zero" data center that requires no net energy from utility power grids? HP Labs said this week that it is developing such a concept, which is being tested at a 3,000 square foot facility at the company's campus in Palo Alto, Calif.
The HP testbed brings together a photovoltaic power array, a cooling system that can use either fresh air or mechanical cooling, and consolidation strategies that boost server utilization to reduce power demand. The secret sauce is management software that can orchestrate the energy supply and demand to maximize the use of renewable power and minimize dependence on the utility grid.
The proof-of-concept confront challenges often seen in solar implementations, including the array's limited capacity of 134 kilowatts and a limited window of generation hours - namely, when the sun shines. This was used to power a testbed comprised of four ProLiant BL465c G7 servers, each with two 12-core 1.8 Ghz processors and 64 GB of memory and a total of 48 KVM virtual machines.
Matching Workloads to Daytime Power Availability
A key component of HP's strategy is using a mix of critical and non-critical workloads that are managed by service level agreements. The HP Labs software estimates the output available from the solar array and the power required to run the applications, and then schedules workloads to take advantage of the daytime power peaks from the array.
This approach may not be suitable for many facilities requiring round-the-clock availability and the ability to scale workloads up and down. But HP said it could be attractive to users with mixed workloads, particularly companies in international markets.
“Information technology has the power to be an equalizer across societies globally, but the cost of IT services, and by extension the cost of energy, is prohibitive and inhibits widespread adoption,” said Cullen Bash, distinguished technologist, HP, and interim director, Sustainable Ecosystems Research Group, HP Labs. “The HP Net-Zero Energy Data Center not only aims to minimize the environmental impact of computing, but also has a goal of reducing energy costs associated with data-center operations to extend the reach of IT accessibility globally.”
HP Labs researchers will present a new research paper, “Towards the Design and Operation of Net-Zero Energy Data Centers,” tomorrow at IEEE’s 13th annual Intersociety Conference on Thermal and Thermomechanical Phenomena in Electrical Systems. HP's presentation is also available.