DATACENTERS data center
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Global data center carbon dioxide emissions are projected to rise from an estimated 220 million tonnes in 2024 to 300–320 million tonnes by 2035. In 2024, Google and Microsoft each consumed more power than over 100 countries. As a result, there is increasing industry pressure for decarbonization. Companies are pursuing direct clean energy agreements, such as Tencent who has pledged to be carbon neutral by 2030, and Microsoft's 2024 agreement to re-open the Three Mile Island nuclear power plant to provide 100% of the electric power for its AI data centers for 20 years.
=== Economic analysis of energy use ===
==== Energy efficiency and overhead ====
The most commonly used energy efficiency metric for data centers is power usage effectiveness (PUE), calculated as the ratio of total power entering the data center divided by the power used by IT equipment.
PUE = Total Facility Power/IT Equipment Power = 1 + Non IT Facility Energy/IT Equipment Energy
PUE measures the percentage of power used by overhead devices (cooling, lighting, etc.). The average U.S. data center has a PUE of 2.0, meaning two watts of total power (overhead + IT equipment) for every watt delivered to IT equipment. State-of-the-art data centers are estimated to have a PUE of roughly 1.2. Google publishes quarterly efficiency metrics from its data centers in operation. PUEs of as low as 1.01 have been achieved with two-phase immersion cooling.
The EPA has an Energy Star rating for standalone or large data centers. To qualify for the ecolabel, a data center must be within the top quartile in energy efficiency of all reported facilities. The Energy Efficiency Improvement Act of 2015 (U.S.) requires federal facilities—including data centers—to operate more efficiently. California's Title 24 (2014) of the California Code of Regulations mandates that every newly constructed data center must have some form of airflow containment in place to optimize energy efficiency.
The European Union (EU) also has a similar initiative: EU Code of Conduct for Data Centres.
Efficiency improvements and renewable energy integration are helping offset some emissions, but fossil fuels remain a major electricity source for data center operations worldwide.
In 2011, server racks in data centers were designed for more than 25 kW, and the typical server was estimated to waste about 30% of the electricity it consumed. The energy demand for information storage systems is also rising. A high-availability data center is estimated to have a 1 MW demand and consume $20 million in electricity over its lifetime, with cooling representing 35% to 45% of the data center's total cost of ownership. Calculations show that in two years, the cost of powering and cooling a server could be equal to the cost of purchasing the server hardware. Research in 2018 showed that a substantial amount of energy could still be conserved by optimizing IT refresh rates and increasing server use. Research for optimizing task scheduling is also underway, with researchers looking to implement energy-efficient scheduling algorithms that could reduce energy consumption by anywhere between 6% and 44%.
In 2011, Facebook, Rackspace, and others founded the Open Compute Project (OCP) to develop and publish open standards for greener data center computing technologies. As part of the project, Facebook published the designs of its server, which it had built for its first dedicated data center in Prineville. Making servers taller left space for more effective heat sinks and enabled the use of fans that moved more air with less energy. By not buying commercial off-the-shelf servers, energy consumption due to unnecessary expansion slots on the motherboard and unneeded components, such as a graphics card, was also saved. In 2016, Google joined the project and published the designs of its 48V DC shallow data center rack. This design had long been part of Google data centers. By eliminating the multiple transformers usually deployed in data centers, Google had achieved a 30% increase in energy efficiency. In 2017, sales for data center hardware built to OCP designs topped $1.2 billion and are expected to reach $6 billion by 2021.
==== Power and cooling analysis ====
Power is the largest recurring cost to the user of a data center. In 2008, the ASHRAE recommended a temperature range of 64.4 °F (18.0 °C) to 80.6 °F (27.0 °C), though some data centers could operate at higher temperatures. However, cooling at or below 70 °F (21 °C) wastes money and energy. Furthermore, overcooling equipment in environments with a high relative humidity can expose equipment to a high amount of moisture that facilitates the growth of salt deposits on conductive filaments in the circuitry.
A power and cooling analysis, also referred to as a thermal assessment, measures the relative temperatures in specific areas as well as the capacity of the cooling systems to handle specific ambient temperatures. A power and cooling analysis can help identify hot spots, over-cooled areas that can handle greater power use density, the breakpoint of equipment loading, the effectiveness of a raised-floor strategy, and optimal equipment positioning (such as AC units) to balance temperatures across the data center. Power cooling density is a measure of how much square footage the center can cool at maximum capacity. The cooling of data centers is the second largest power consumer after servers, with cooling taking about 7% to 30% of energy usage (depending on efficiency), compared to an average of 60% of energy used by servers.