Network World
Wednesday, November 11, 2009
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Place for flywheels in your UPS?

Keeping data centers up and running during power outages traditionally has required banks of batteries to feed gear while generators are spooled up. There is an alternative, however.

Fujitsu pumps out 10G Ethernet data center switch
11/11/09
Fujitsu has unveiled a 10Gbps Ethernet switch designed to handle important applications in an energy efficient way.

Acadia, Cisco, EMC, VMware data center cloud unveiled
11/11/09
Cisco, EMC and VMware last week unveiled the much rumored joint venture to sell their products to companies wanting to build internal clouds. Called Acadia (for who knows what reason), the joint venture is a collaboration between the three companies that will launch in 2010 and sell what they call vBlocks, pre-configured packages of Cisco UCS blade servers, EMC storage gear, VMware virtualization software and EMC Ionix management software.

Is e-mail a perfect cloud application?
11/11/09
In the beginning there was email. And email was run on a UNIX server. The network was devoid of PCs. So all email was accessed via a terminal and a command line interface.

Pentadyne today will announce the VSS+, a 190-kilowatt flywheel system that sidesteps many battery shortcomings.

Batteries require ongoing maintenance to ensure they can still hold a charge. They also require air conditioning, are heavy, eat up valuable data center space and have to be replaced every two to four years.

Pentadyne's flywheel system, says CEO Mark McGough, requires virtually no maintenance for its 20-year life expectancy, always has the same kinetic energy when the wheel is spinning at the prescribed revolutions per minute (rpm), has no special thermal requirements, and is lightweight and takes up only 5 feet of floor space.

The downside is the VSS+ can generate power for only 12.5 seconds.

McGough says that's enough to run roughly 100 blade servers while generators are coming online, and he says more than 98% of power problems are sags and interruptions lasting less than 2 seconds. As many as eight VSS+ systems can be ganged in parallel to address different power needs.

Flywheels have been around a long time, but Pentadyne's advantage is in the wheel's material. Kinetic energy equals mass multiplied by velocity squared.

"If you double the size of the mass, you get twice the energy," McGough says. "But if you double the velocity, you get four times the energy."

Metal flywheels can't be spun at high speeds for fear of catastrophic failure, so the only way to get more energy out of them is to increase their weight, which requires more energy to operate. Pentadyne's wheel is made of carbon fiber and can be spun at 50,000 rpm.