Power usage effectiveness (PUE) is a ratio that describes how efficiently a computer data center uses energy; specifically, how much energy is used by the computing equipment (in contrast to cooling and other overhead that supports the equipment). PUE is the ratio of the total amount of energy used by a computer data center facility to the energy delivered to computing equipment. PUE is the inverse of data center infrastructure efficiency. PUE was originally developed by a consortium called The Green Grid. PUE was published in 2016 as a global standard under ISO/IEC 30134-2:2016 An ideal PUE is 1.0. Anything that isn't considered a computing device in a data center (e.g. lighting, cooling, etc.) falls into the category of facility energy consumption. Issues and problems with the power usage effectiveness The PUE metric is the most popular method of calculating energy efficiency. Although it is the most effective in comparison to other metrics, PUE comes with its share of flaws. This is the most frequently used metric for operators, facility technicians, and building architects to determine how energy efficient their data center buildings are. Some professionals even brag about their PUE being lower than others. Naturally, it is not a surprise that in some cases an operator may “accidentally” not count the energy used for lighting, resulting in lower PUE. This problem is more linked to a human mistake, rather than an issue with the PUE metric system itself. One real problem is PUE does not account for the climate within the cities the data centers are built. In particular, it does not account for different normal temperatures outside the data center. For example, a data center located in Alaska cannot be effectively compared to a data center in Miami. A colder climate results in a lesser need for a massive cooling system. Cooling systems account for roughly 30 percent of consumed energy in a facility, while the data center equipment accounts for nearly 50 percent. Due to this, the Miami data center may have a final PUE of 1.8 and the data center in Alaska may have a ratio of 1.7, but the Miami data center may be running overall more efficiently. In particular, if it happened to be in Alaska, it may get a better result. Additionally, according to a case study on Science Direct, "an estimated PUE is practically meaningless unless the IT is working at full