Data centres can be efficient and green

Schneider Electric, the global specialist in energy management and automation, makes efficiency a top priority in data centre design due to both environmental and cost concerns.

As the need for data centres continues to grow, this places a tremendous amount of pressure on the electrical power utility providers. In a typical data centre, which requires vast amounts of clean, uninterruptible power, power usage can range from a few kilowatts to tens of megawatts.

This is power that is free from all the spikes, dips, sags or similar power disturbances. The power also has to come from a steady source that is not interrupted in any way.

“The electrical power is used to feed the active information technology (IT) equipment. This includes computer servers, network switches, network routers, storage servers and similar pieces of active equipment. A portion of the power supplied to the data centre then gets directed to auxiliary equipment such as computer-room air-conditioners that will help dissipate the heat generated by all active data centre equipment and also control relative humidity,” explains Riaan de Leeuw, VP of Schneider Electric’s IT division in the Anglophone Africa region.

Ideally, the bulk of this power should go to the active equipment and very little to no power to all the non-active equipment in the data centre. Usually, the percentage that goes to the active equipment is about 50%, and to the cooling apparatus about 35% of the total power supplied, with the remainder going to other services like lighting, fire detection and suppression, access control and other smaller power consumers.

“Unfortunately, this is not always the case, especially when looking at older data centres that still employ traditional methods of cooling,” he says.

Because data centre cooling takes the second most amount of power after the IT active equipment, it makes sense to focus efforts to reduce power consumption in making the cooling work more efficiently.

One option would be to design and use the best-fit cooling methodology from the ground up. Or, in the case of an existing data centre, retrofitting certain aspects of the data centre could also dramatically increase cooling efficiencies.

“I also think that renewable energy in data centres can significantly reduce the power usage, as innovation and technologies continue to evolve every day in the energy storage sector. I do not doubt that very soon we will get to a stage where the initial capital expenditure for the installation and use of solar technologies will be within reach and rate of return expectations of many customers. This will make the use of solar energy widely accessible in regions of the world where there is plenty of sunshine available,” De Leeuw says.

“Another possibility would be to use solar energy to chill water into ice during the day via an absorption type refrigeration system, which could then be used to cool the data centre during the evening.”