Within the United States are about 3 million data centers, the buildings or rooms housing computer servers. Of these 3 million, around 3,000 are large data centers and the rest are small server rooms in businesses.
Power use effectiveness (PUE) is the ratio of how efficiently a computer data center uses energy. Of the world's larger data centers, most average a PUE of 2.5, As a best practice, PUE should be less than 1.5. PUE is calculated with the following equation:
Power use effectiveness = total energy used in data center/energy used to run processors
In addition to lowering their PUE, data centers can implement a number of best practices to cut energy usage. Some of these best practices include:
The most practical method for improving PUE and implementing best practices is to use a power meter to monitor energy. Information from a power meter such as feedback on energy consumption and daily usage are effective energy management tools. Combining power monitoring with best practices makes data centers more energy efficient.