Data centres could save a third of their lighting costs by replacing black server cabinets with grey ones, believes Mark Hirst, T4 Product Manager, Cannon Technologies Limited. In fact, choosing to use grey or white cabinets during an equipment refresh can make bigger savings than intelligent lighting systems which use movement-sensitive lights.
Ambient light levels in a server room are crucial for the engineers who maintain the systems but ironically it can be the equipment itself which can make a significant impact. The light reflective value (LRV) of black server racks can be as little as 5% whereas grey or white will reflect up to 80% of the light. “Using the LRV of the server cabinet colour, it is not unrealistic to see a saving of around 30% on the lighting in a data centre,” says Hirst.
“It may also be surprising to some people that lighting can account for 3-5% of the power costs in a data centre,” continues Hirst. This comes at a time where data centre owners are facing a double increase in power costs. Not only have some seen power costs rise by over 6% as contracts have been renewed but the carbon taxes introduced as part of the European Union’s green policies will further increase bills.
The savings that can be made are significant. A small 1MW data centre where 5% of the total power is consumed by lighting will use 50kW to light the server rooms. A 30% reduction would deliver a saving of 15kW. Assuming 10p per kWh this data centre could save £36 per day, or £13,140 per year, the equivalent of a junior operator’s salary.
An average UK data centre, which would draw around 5MW, would save over £65,000 per year. On top of those power cost reductions there would also be the savings in carbon tax and all of this could be achieved by just choosing different colour cabinets. “Manufacturers have already taken this on board,” says Hirst. “HP’s kit is now in grey and Cisco’s new data centre in the USA used bright white cabinets. In the data centre, grey is definitely the new black.”