How Green Are Green Data Centers? Calculating Data Center CO2 Emissions

By Green Edge Compute October 20, 2021

Efforts are made to make data center operations more environmentally friendly and sustainable, but the industry can become even greener. By identifying and optimizing critical CO2 emission drivers, the industry can measure and calculate its impact on the environment more precisely and become genuinely sustainable.

The data center industry has become one of the most energy-consuming and environmentally challenging industries globally. The industry is increasingly turning green to cope, transforming its operations to accommodate a more sustainable approach.

But what makes a data center green and sustainable? Several metrics are proposed to measure data center efficiency but may ultimately prove insufficient to determine the industry’s negative impact on our environment. To become truly green, the entire value chain needs to be taken into consideration.

Increasing Electricity Demands and Environmental Challenges

As the need for computing power and data storage increases, the data center industry will take up more and more of the global electricity consumption. Several forecasts indicate that the total electricity demand of information and communications technology (ICT) will accelerate in the 2020s and reach all-time high levels by 2030 and that the data center industry will take a larger slice (see figure 1).

Energy Forecast 2010-2030

Figure 1: Energy forecast 2010-2030 (Source:

This is turning into a significant problem for the data center industry. Some cities have already stopped building new data centers because of a lack of available power in the region. For instance, Amsterdam, the capital of the Netherlands, called a halt to the establishment of new data centers a few years ago. Claiming to be part of Europe’s largest data center hub and experiencing massive growth, the city decided to postpone further data center development projects.

“Data centers have become indispensable facilities for almost all residents, businesses and institutions, but they also take up a lot of space and, due to high energy consumption, take a big load on the electricity grid. At present, municipalities have hardly any instruments at their disposal to steer where the data centers are located, or which requirements they must meet,” the municipality of Amsterdam stated in a press release.

Additionally, the data center industry currently generates the same amount of carbon emissions as the entire airline industry. According to some estimates, the carbon footprint of our gadgets, the internet, and the systems supporting them account for 3,7 % of global greenhouse emissions. And these emissions are predicted to double by 2025 and reach 14 percent in 2040.

The increasing demand for computing power and data storage globally is becoming a significant environmental problem because of the massive energy consumption in today’s traditional data centers. If the forecasts are nearly in line with what will happen, we need to find solutions to fix the data center industry's problems as soon as possible.

Different Shades of Green

The data center industry is well aware of the strain they pose on our environment. In recent years, the data center industry has transformed its operations in more green and sustainable ways, following the increasing public focus on climate change. Google, for instance, announced its intention to spend more than USD 2 billion in new renewable energy infrastructure across the US, South America, and Europe in advance of the Global Climate Strike in 2019.

Google’s initiative is applaudable, and they are not alone. The data center industry, in general, is working intently on becoming greener and more sustainable. International players such as Microsoft aim to become carbon negative by 2030, and innovative co-location players focus on developing sustainable solutions for the industry.

These initiatives are arguably a step in the right direction. However, most of these initiatives seem to amount to placing data centers in regions where access to renewable energy is plentiful or compensating by investing in renewable energy projects to balance “dirty” energy consumption with clean energy initiatives.

But can data centers truly become green only by using or investing in renewable energy?

Redefining Green Data Centers: Taking the Entire Value Chain into Consideration

Renewable energy adoption in the data center industry is essential. But other initiatives are equally, if not more, important to consider. However, to measure the sustainability gains of other initiatives correctly, new metrics need to be considered.

Currently, the data center industry relies on two important metrics to measure data center efficiency:

  • Power Usage Effectiveness (PUE): PUE is the industry-wide, predominant metric for calculating data center efficiency. It is a ratio that gives insight into how efficiently a data center uses energy by relating the total energy consumption of the data center to the energy consumption of its cooling and supporting IT equipment. According to the Norwegian independent research organization Sintef, efficient data centers can achieve PUE values below 1,2. However, one study demonstrated that Nordic data centers, on average, achieve a PUE value of 1,71, leaving considerable room for improvement. Leveraging more efficient cooling technologies will help reduce these PUE values.
  • Energy Reuse Effectiveness (ERE): Several facilities now reuse the energy generated from the data center in other parts of the facility. However, the PUE calculation cannot consider alternative uses for waste energy generated as a byproduct of the data center. To account for these metrics, the non-profit industry consortium The Green Grid has proposed and defined a new metric, Energy Reuse Effectiveness (ERE). ERE provides data center operators with greater visibility into energy efficiency by reusing any recovered energy from the data center and waste heat utilization.

Both PUE and ERE are necessary and valuable metrics for measuring the energy efficiency of any data center. However, we firmly believe that other metrics also need to be considered to determine the true “greenness” of data center operations. The entire value chain needs to be taken into consideration. This means also considering other relevant factors, such as:

  • Data center construction processes: A new breed of micro-edge data centers in urban areas promise to eliminate CO2 emissions related to data center construction processes. Instead of building new infrastructure and large-scale warehouses in rural areas, these micro-edge data centers are more compact, making it easier to leverage existing buildings in urban areas for data center operations. As micro-edge data centers increase, applicable calculations to measure their positive environmental impact need to be developed.

  • Equipment production: As micro-edge data centers can reduce the total size while retaining necessary computing power and data storage capacities, the number of required server racks also decreases. This may translate into lower CO2 emissions from equipment production processes which also need to be considered.
  • Cooling technology: Choosing more efficient cooling technologies may reduce consumption levels and improve the potential for waste heat utilization. Traditional data centers typically leverage suboptimal air-based cooling systems to eliminate heat, which results in higher energy consumption levels and low waste heat temperatures. On the other hand, emerging liquid cooling technologies generate higher waste heat temperatures, reduce energy use for cooling, and enable the creation of more compact data centers to be located in urban areas. 
  • Data center location: Rurally located data centers are advantageous in many situations, considering space and electric power availability and access to efficient cooling methods, such as free cooling in the mountains. However, rural data centers typically lack urban heat recipients making waste heat utilization challenging to realize in practice. Where a data center is located has a significant influence on its potential sustainability gains, making it an essential factor to consider when calculating data center CO2 emissions.


Testing, Measuring, and Calculating CO2 Emissions in Micro-Edge Data Centers

As part of our pilot project, Green Edge Compute is currently developing a green, micro-edge data center located in the heart of Trondheim, Norway. Relying exclusively on renewable energy, leveraging existing buildings, and using efficient cooling methods, the new data center will consume close to 40 percent less energy than traditional data centers and enable waste heat utilization in the city’s district heating system.

As part of this project, we work closely with Sintef to measure and calculate CO2 emissions by considering the abovementioned factors. The results will be presented to the public after the pilot project is finalized.

Read also: Green Edge Compute to Launch Edge Data Center Pilot Project

In Green Edge Compute, we aim to push sustainable data operations to its limits. We believe it is possible to become truly “green” by considering the entire value chain.

Want to be part of our pilot project?  Read more ›