Tailpipe's Emissions Explained

14th October 2024

Across the month of September 2024, Tailpipe’s own use of cloud computing produced 8.31 kgCO2e of emissions, of which: 

1.82 kgCO2e were embodied emissions, and  

6.49 kgCO2e were operational emissions. 

That’s the equivalent of driving 33 miles (53 km) in a typical petrol car. 

Tailpipe calculated this by assessing the eight AWS EC2 instances that it utilized across the 30 days of September 2024. These instances were: t3.micro, t2.micro, c6a.metal, c6i.metal, c7i.metal-48xl, m7g.large, t4g.nano, t4g.small. 

Operational Emissions 

Operational emissions result from the energy generation process that provides the electricity that cloud service providers’ data centers need to power cloud computing services. 

Diagram showing the transmission of power from a power plant to a data center to a server.

First, let’s break down how Tailpipe calculated its operational emissions.  

 

Instance 

Using its central database, Tailpipe could identify the following variables for each instance’s hardware: 

Instance 

CPU  

TDP 

RAM (GB) 

DDR 

GPUs 

SSD (GB) 

Instance vCPU 

Server vCPU 

NICs 

t3.micro 

Intel Xeon Platinum 8175M 

240

t2.micro 

Intel Xeon E5-2676 v3 

145 

c6a.metal 

AMD EPYC 7R13 

225 

384 

192 

192 

c6i.metal 

Intel Xeon Platinum 8375C 

300 

256 

128 

123 

c7i.metal-48xl 

Intel Xeon Platinum 8488C 

385 

384 

192 

192 

m7g.large 

Graviton3 

250 

64 

t4g.nano 

Graviton2 

150 

t4g.small 

Gravtion2 

150 

 

It then multiplies these variables by power draw data, depending on the CPU utilization of each of Tailpipe’s instances for every hour of the month. For example, for the m7g.large instance: 

Component 

Total Power Draw (Wh) 

CPU 

1006.8

GPU 

RAM 

1079.77

SSD 

Motherboard 

954.92

NIC 

7333.8

Total 

10375.29

 

The total power draw of the m7g.large instance for the month of September 2024 is therefore 10375.29 Wh.

 

Network Storage 

Tailpipe then adds the impact of network storage. The m7g.large instance does not have any SSDs or HDDs, so its storage is maintained on the AWS Elastic Block Storage infrastructure. In September, Tailpipe stored 57.19 GB of data in the m7g.large instance’s network storage. 

This quantity is applied to the Tailpipe methodology: 

((0.0029 * GB of Network Storage) * Hours of Utilization) * Power Supply Efficiency Factor    

((0.0029 * 57.19) * 720) *1.1 = 131.35 Wh 

 

Instances in the Same Data Center 

Tailpipe’s m7g.large instance was based in a data center in Stockholm in September 2024. The next stage of the methodology is to add together the impacts of the instances that were based in the same data center, and the networking that originated from that data center, during the same period. 

Two other Tailpipe instances were based in the Stockholm data center in September: t3.micro and t4g.nano. 

Name 

Instance (Wh) 

Network Storage (Wh) 

t3.micro 

34.15

0.0 

t4g.nano 

175.49

0.0 

m7g.large 

10375.29

131.35 

Total 

10584.93

131.35 

 

Data Transfer and Networking 

The impact of networking must then be calculated. Tailpipe multiplies the GB of data transferred by specific figures for each networking type, accounting for the different power draws of networking across these different networks. 

Instance Networking from Stockholm 

Type 

GB  

Formula 

Power Draw (Wh) 

Intra-region 

0.00 

(0.0006 * Intra-region GB) / 1000 

Inter-region 

119.86 

(0.0006 * Inter-region GB) / 1000 

0.00007 

External 

0.71 

(0.0058 * External GB) / 1000 

0.000004 

 

Non-Instance Networking from Stockholm 

Type 

GB  

Formula 

Power Draw (Wh) 

Intra-region 

0.00 

(0.0006 * Intra-region GB) / 1000 

Inter-region 

121.03 

(0.0006 * Inter-region GB) / 1000 

0.00007 

External 

0.64 

(0.0058 * External GB) / 1000 

0.000004 

 

Total Operational Emissions

The complete Tailpipe operational emissions methodology is: 

((Instance + Network Storage + Intra-Region Data Transfer + Intra-Region Non-Instance Networking) * PUE) + (Inter-Region Data Transfer + External Data Transfer + Inter-Region Non-Instance Networking + External Non-Instance Networking)) * Carbon Intensity * Power Transmission Losses)   

Where PUE (the Power Usage Effectiveness of the Stockholm data center) is 1.1. 

Adding the figures above into this formula gives the following result: 

((10584.93 + 131.35 + 0 + 0) * 1.1) + (0.00007 + 0.000004 + 0.00007 + 0.000004)) = 11787.91 Wh 

This figure must then be multiplied by the carbon intensity of the Swedish grid mix in September 2024. This was 0.00001984 kgCO2e/Wh. 

11787.91 * 0.00001984 = 0.23 kgCO2e 

After applying the same formula to the five other instances Tailpipe utilizes, Tailpipe’s total operational emissions for September 2024 worked out to be 6.49 kgCO2e

 

Embodied Emissions 

Tailpipe then calculates the embodied emissions of its instances. Embodied emissions are released during the manufacture, shipping and disposal of the physical hardware that hosts cloud computing services.  

Diagram showing the lifecycle of cloud computing equipment, from manufacture, to transport, to use stage, to disposal.

Taking the m7g.large instance as an example, Tailpipe first calculates the embodied emissions of the server that hosts it. This is the m7g.metal server. It takes embodied emissions values from the Green Cloud Computing study and multiplies them based on the specific hardware in the m7g.metal server. 

Component 

Formula 

Values 

Result (kgCO2e) 

CPU 

CPU Units * ((CPU Die Size) * 0.0197 + 9.14)  

1 * ((347.3) * 0.0197 + 9.14) 

15.98 

RAM 

RAM Units * ((RAM Capacity/RAM Density) * 2.2 + 5.22)   

1 * ((256/22.37) * 2.2 + 5.22) 

30.4 

SSD 

SSD Units * ((SSD Capacity/SSD Density) * 2.2 + 6.34)   

0 * ((0/0) * 2.2 + 6.34) 

HDD 

HDD Units * 31.11   

0 * 31.11 

Motherboard 

66.10 

66.1 

66.1 

PSU 

Power Supply Units * (Weight * 24.3) 

2 * (2.99 * 24.3) 

145.31 

Assembly 

6.68   

6.68 

6.68 

Enclosure 

150 

150 

150 

Total 

 

 

430.45 

 

These figures are then scaled down for the specific m7g.large instance. The instance is a virtual machine, meaning that it uses the resources of the m7g.metal server, without having physical machinery of its own. 

Component 

Formula 

Values 

Result (kgCO2e) 

CPU 

15.98 * (Instance vCPU/Server vCPU) 

15.98 * (2/64) 

0.5 

RAM 

30.4 * (Instance Memory/Server Memory) 

30.4 * (8/256) 

0.95 

Motherboard 

66.1 * (Instance vCPU/Server vCPU) 

66.1 * (2/64) 

2.07 

PSU 

145.31 * (Instance vCPU/Server vCPU) 

145.31 * (2/64) 

4.54 

Assembly 

6.68 * (Instance vCPU/Server vCPU)  

6.68 * (2/64) 

0.2 

Enclosure 

150 * (Instance vCPU/Server vCPU) 

150 * (2/64) 

4.69 

Total 

 

 

12.95 

 

Because the m7g.large instance hosts network storage (rather than onboard storage in the SSDs or HDDs of the m7g.metal server), the impact of this needs to be added too: 

Network Storage Units * 0.0028

= 57.19 * 0.0028

= 0.16

Finally, the impact of networking equipment is added. This is 10.12 kg CO2e per instance, to account for an average of two switch ports per instance.

The total embodied emissions of the m7g.large instance across its entire lifespan are therefore:  

12.95 + 0.16 + 10.12 = 23.23 kgCO2e 

 

Disposal 

Tailpipe then adds the impact of disposal onto this figure. This is a 1.8% reduction in the total carbon emissions of the physical hardware: 

23.23 – (23.23 * 0.018) = 22.81 kgCO2e 

 

Time Share 

The final step in the embodied emissions calculation is to factor in Tailpipe’s use of its instances as a percentage of their total 6-year lifespan. 

22.81 * (customer usage period/instance lifetime) 

22.81 * (720/52596) = 0.31 kgCO2e 

This means that in September 2024, the m7g.large instance generated 0.31 kgCO2e through its embodied emissions, and 0.23 kgCO2e through its operational emissions – producing a total of 0.54 kgCO2e. This result is unusual in that the embodied emissions are larger than the operational emissions, which suggests that the m7g.large instance was not being utilized efficiently in this month.

The same embodied emissions formula was applied to the seven other instances that Tailpipe utilized in September. The resulting figure for Tailpipe’s total embodied emissions for September 2024 was 1.82 kgCO2e

 

Find Out More 

For a more detailed breakdown of how Tailpipe calculates emissions, see the Tailpipe Methodology. For an explanation of how Tailpipe can reduce an organization’s cloud spend and carbon emissions, see Tailpipe’s Recommendations

To discuss what Tailpipe can do to measure and reduce your cloud computing spend and emissions, get in touch with us here