According to reports, one of the biggest costs in a data centre is power cost. Power is needed to fire the servers and storage systems. And since these systems heat up, power is again required to cool the systems with airconditioning.
In the dot-com era, data centres consumed 1 or 2 MW. Now it’s common to find facilities that require 20 MW, and already some of them expect to use ten times as much in the years to come. For countries, data centre power consumption is expected to put an enormous burden on their power grids.
Not surprisingly, an enormous amount of innovation, right from the semiconductor level, is today going into finding solutions to reduce power consumption in computing systems. IBM’s India Software Lab in Bangalore has just contributed towards that. It has developed a system to run data centres on solar power, and is making it commercially available, perhaps the first such commercial offering in the world.
“Until now, no one has engineered solar power for efficient use in IT,” said Rod Adkins, senior VP of IBM’s systems and technology group, who was in Bangalore last week. “We’ve designed a solar solution to bring a new source of clean, reliable and efficient power to energy-intensive, industrial-scale electronics.”
The first implementation is being done at the Bangalore lab itself. A solar power array has been installed, spread over more than 6,000 sft of the lab’s rooftop. Kota Murali, chief scientist at IBM India, says the installation is capable of providing a 50-kilowatt of electricity for up to 330 days a year, for an average of five hours a day. The advantage of solar power is that it is DC (direct current), unlike grid power that is AC (alternating current).
Processors run on DC, so when you use grid power, you need to convert AC to DC. In the process of that conversion, you lose about 13% of power. On the other hand, when you do a DC to DC conversion, the loss is only 4%. So you have a saving of close to 10%.
Adkins said while the solution could bring a 10% saving in developed markets, it could be even better in emerging markets, where there are many places that are not served or inadequately served by the grid. Murali says his facility in Bangalore suffers a 3 to 6 hour power cut on average every day, forcing them to depend on diesel generators. “The per unit cost of that is much higher than even solar,” he says.
The India team’s innovation has been in integrating DC IT systems, water-cooled systems and solar power. Water-cooled systems are also a relatively new phenomenon; water is far more efficient at cooling than is air. “These technologies were developed in silos, but we are seeing huge benefits when we connect them,” Adkins says.
He says the history of solar-power shows that its biggest commercial successes come when the technology is tuned for specific uses, as was being done now by creating a preengineered solution for future data centres. “The first solar calculator hit store shelves in 1978 and was an instant hit. This is a solar solution for a slightly bigger calculator, a 30 teraflop datacentre.”