Power Assure won this year's energy efficiency prize at the Cleantech Open for good reason. A typical server wastes 60-90% of its energy load while in idle mode, preparing for that moment when a heavy data load requires a burst of server activity. Most of the time, the servers are just standing by waiting. Meanwhile they consume huge amounts of energy.
2 ex-HP executives realized there was an opportunity here, what they call "holistic power management." Their patent-pending software captures minute-by-minute data on the server loads and then shifts utilization of power as needed. They maintain a much smaller buffer of 'idle' energy, 10% instead of the typical 75%. This provides for sudden bursts of demand, while conserving on energy.
The Power Assure system also measures the cooling loads, typically a full 50% of the energy used by a server farm. The system monitors the cooling needs and, provided the facility has the ability to variably adjust cooling temperatures, ensures that the system is not wasting energy by over cooling.
Companies like Facebook and Yahoo, with huge variable server loads, are jumping in to test out this holistic power management tool. They get 'green' cred while conserving big time on the other kind of green -- cash. According to Donnie Foster one of the company's co- founders, a large server farm will spend $6 million per year on energy costs. To be able to recoup $4 million of that money is great news for a company's bottom line, especially in hard economic times.
A detailed explanation of 4 different implementations is available on the Power Assure site. For other Green IT strategies, check out my recent 'Smart Power' post.