# Calculating PUE, DCiE, Cost and the Environmental Impact – Best Practises

PUE and DCiE rely on the input values to be kW or kWh. To convert the results which are provided in amps to kWh the following calculation must take place: Yearly kWh = (Amps x Voltage /1000) *8760 The number 8760 refers to the number of hours in a year. A year has been selected simply to draw more meaningful conclusions such as annual consumption and annual cost. Once a yearly kWh value has been attained, PUE and DCiE can be calculated. To calculate monetary costs associated with powering the data centre, the kWh figure must be multiplied by average price per kWh in the U.K, currently 13.7pence. (ConfusedAboutEnergy, 2012) Cost in Pounds = Yearly kWh * 0.137 Additionally as the project is looking at reducing the environmental impact of the data centre, with the results gathered, it is possible to estimate the amount of co2 emissions generated. Pretorius et al. (2011) state that one kWh generates approximately 950 grams of co2. This would then mean the following formula can be applied to calculate the environmental impact : co2 Emissions in Tonnes = total kWh * 0.00095

We have overcome luck of kw/h data by above calculations while conducting Greening the Data Centre Project with Final year project Graduate Auzzam Chaudhri.