Simple Methods, High Returns.
The good news is that there are many simple, affordable and proven techniques to increase data centre efficiency without major infrastructure changes or sacrificing protection. Here’s a few of them:
Eliminate the PDU and Raise Distribution Voltage
If you are designing a new data centre, or performing a major infrastructure upgrade, try removing the power distribution unit (PDU) step-down transformer from the power chain and distributing power at a higher voltage to increase efficiency. This can be achieved by implementing the 400/230V (or 415/240V) power distribution method used by most European data centres.
European voltage equivalents are available for most of the IT equipment that North American data centres use today, meaning businesses can collect the benefits of increasing distribution voltage without having to deploy special power supplies in the IT gear.
Employ High-efficiency UPS Hardware
Efficiency is profoundly influenced by uninterruptible power systems (UPS) design or operating mode. Among the latest generation of UPS's are models that offer multi-mode operation, often called “eco-mode” or “high-efficiency mode.” The UPS operates in high-efficiency mode unless power conditions warrant an instantaneous transition to the higher protective level of double-conversion mode. This new multi-mode technology provides exactly the level of power protection needed under the conditions of the moment.
The results can be dramatic as even small increases in UPS efficiency can quickly translate into tens of thousands of dollars. For example, assuming a utility rate of 10 cents per kWh, a 60 kW N+1 redundant configuration would save more than £50,000 in five years and the savings compound with data centre size. Additionally, the high efficiency UPS radiates much less heat, thus decreasing the load on the HVAC equipment, providing further power cost reduction.
Use DC Power Distribution
DC power systems are another means of reducing conversion stages along the power chain to increase efficiency. Although DC distribution has a unique set of limitations that should be taken into consideration, practical techniques are available to mitigate most issues.
A typical DC system distributes power at approximately 380V DC using one of two methodologies: a wide-range voltage methodology that accommodates direct connection of the battery backup to and a narrow-range voltage methodology that requires a DC/DC converter to stabilise the bus voltage during battery discharge/recharge. Both methodologies obtain DC power using an AC/DC converter. It is important to note that data centres with AC distribution and high-efficiency mode UPS hardware can enjoy the same or better efficiency than facilities that use DC distribution. AC distribution also has the advantage of being significantly more familiar to most data centre operators.
With energy costs representing the single largest component of IT operations, the benefits of these strategies can be substantial. Even a small data centre can save tens of thousands of pounds a year in utility bills by making a few changes, and larger data centres could potentially save millions over time without ever compromising data centre performance or reliability.With a more efficient allocation of power you will not only reduce utility bills and the total cost of operation, but also achieve more capacity with available power distribution and cooling systems – delaying the point where those systems would have to be upgraded to support data centre expansion.