“Let’s have a look at some data on all of the above.
How Much Energy Is Bitcoin Consuming?
For context, at time of writing, the Cambridge Bitcoin Energy Consumption Index (CBECI) estimates Bitcoin’s annual energy use at 79 terawatt hours (TWh).
Figure 17 from that report (page 27), shown below as figure One, demonstrates the typical energy sources for miners around the world.
Figure one: energy sources by region (source: Cambridge Centre For Alternative Finance).
China is now out of the picture, and fresh data from the Bitcoin Mining Council (BMC) (figure two) shows that over two-thirds of the membership, representing almost one-third of the network hash rate, is being powered by low-emissions energy sources, and that global Bitcoin mining is now estimated to receive 56% of its energy needs from sustainable sources (solar, wind, hydro, nuclear, geothermal and other “renewables”).
Figure two: Bitcoin energy mix (source: Bitcoin Mining Council)
To that end, I offer a new global mining profile and carbon intensity figure of 280 grams of CO2 per kWh, using my original methodology presented in this previous article (see section one on energy mix) based on the below assumed generation mix, and 50th percentile IPCC carbon intensity figures (see page 190). The dramatic drop is a result of moving a large proportion of the network from coal to gas, cutting the carbon intensity of Bitcoin by a third.
Figure three: Carbon intensity and energy mix comparative data, CBECI and BMC scenarios
As can be seen, since the Chinese exodus, Bitcoin’s carbon intensity has dropped by a third, from 419 to 280, mainly as a result of shifting away from coal to the much cleaner natural gas. Comparing Bitcoin to global primary energy production shows that Bitcoin is less than half as carbon intense, and when compared to the world’s grid, is over 40% less carbon intense.
So! Now that we know Bitcoin’s carbon intensity is 280 g of CO2 per kWh (or 0.28 megatonnes [Mt] of CO2 per TWh), and that Bitcoin uses 79 TWh per year, we can quickly arrive at an emissions figure of 22.1 Mt CO2 per year.
Bitcoin’s Energy Use Compared To Building And Construction
- Non-residential buildings: 9,330 TWh
- Residential buildings: 26,481 TWh
- Construction: 5,833 TWh
- Sector total energy use: 40,830 TWh
- Bitcoin: 79TWh, or 0.19% of the building and construction industry
- Sector total emissions: 12,735 MtCO2
- Bitcoin: 22.1 Mt CO2 or 0.18% of the building and construction industry
- Sector carbon intensity: 330.6 g per kWh (about 20% more intense than Bitcoin)
Figure five: Bitcoin versus buildings — yearly energy use, in TWh
Bitcoin’s Energy Use Compared To The Transportation Industry
Using the above ratios, and a total sector energy use of 118 quad BTU in 2020, or 34,582 TWh, we have the following:
- Light-duty passenger road vehicles: 15,424 TWh (44.6%)
- Air transportation: 4,046 TWh (11.7%)
- Bus: 1,321 TWh (3.8%)
- Other transportation: 859 TWh (2.5%)
- Road freight vehicles (heavy vehicles and other trucks): 8,059 TWh (23.3%)
- Marine shipping: 4,063 TWh (11.7%)
- Rail: 793 TWh (2.3%)
- Total energy use: 34,582 TWh
- Bitcoin: 79 TWh, or 0.23% of the transportation industry
- Sector carbon intensity: 234 g CO2 per kWh (about 16% less intense than Bitcoin, 50% less intense than the world grid)
Figure eight: Bitcoin versus transportation — yearly energy use, in TWh
It’s not a nice thing to acknowledge, but if you’re charging your Tesla on the U.S. natural-gas-powered grid, or the slightly-greener world average grid, or basically anything other than your own solar roof panels, you’d be doing 50% less damage to the environment by driving an internal combustion vehicle. We just calculated the carbon intensity of fossil-fuel-driven transport to be 234 g CO2 per kWh based on emissions and energy data from the EIA and IEA (I swear to God, they do that with their acronyms on purpose!). Here, the U.S. Environmental Protection Agency (EPA) shows that most petroleum products (including jet fuel, gasoline and diesel) have a carbon intensity of around 65 kg CO2 per mmBTU to 75 kg CO2 per mmBTU, or, about 222 g CO2 per kWh to 256 g CO2 per kWh — which gives us strong validation of our calculated transportation industry figure of 234 g CO2 per kWh.
Revisiting Bitcoin’s Energy Use Compared To Finance, Gold And The Military-Industrial Complex
As per my previous piece, the breakdown for the gold mining industry, excluding additional refining of gold for industrial use, is as follows:
- Total energy use: 265 TWh
- Bitcoin: 79 TWh, or 29.8% of the gold mining and jewelry industries
- Total Emissions: 145 MtCO2
- Bitcoin: 22.1 Mt CO2, or 15.2% of the gold mining and jewelry industries
- Sector carbon intensity: 547 g per kWh (about 95% more intense than Bitcoin)
Finance And Insurance
As per my previous piece, we found that the finance sector emitted 1,368 Mt CO2 per year, using the help of the University of California, Berkeley’s (UCB) CoolClimate Network (CCN) model. While it doesn’t explicitly provide a figure for energy use, it provides a great breakup of where the emissions come from. As shown in figure 10 below, 80% of emissions came from transportation, with 20% going to facilities and procurement. Using the same approach we did with healthcare earlier, we will assume a carbon intensity of 250g CO2 per kWh for travel, and 487g CO2 per kWh (i.e., “the world grid”) for procurement and facilities.
The resulting energy breakdowns are as follows:
- Transportation: 4,377 TWh (88.6%)
- Facilities: 309 TWh (6.3%)
- Procurement: 253 TWh (5.1%)
- Total energy use: 4,939 TWh
- Bitcoin: 79 TWh, or 1.6% of the finance and insurance industries
- Total emissions: 1,368 MtCO2
- Bitcoin: 22.1 Mt CO2, or 1.6% of the financial and insurance industries
- Sector carbon intensity: 277 g per kWh (about 1% less intense than Bitcoin)
The industrial and manufacturing sectors are far more procurement- and-facilities driven than the financial sector, which is predominantly human- and travel-driven. Transportation accounts for 80% of the financial industry’s energy use. In the manufacturing industry, it is closer to only 25%. Therefore, we have the following:
- Military fuel/transportation use: 275 Mt CO2, 1,100 TWh
- Military facilities use: 150 Mt CO2, 308 TWh
- Military industry fuel/transportation use: 525 Mt CO2, 2,100 TWh
- Military industry facilities and procurement use: 1,550 Mt CO2, 3,183 TWh
- Total energy use: 6,691 TWh
- Bitcoin: 79 TWh, or 1.18% of the military-industrial complex
- Total emissions: 2,500 MtCO2
- Bitcoin: 22.1 Mt CO2, or 0.88% of the military-industrial complex
- Sector carbon intensity: 374 g CO2 per kWh (about 33% more intense than Bitcoin)
As always, the numbers speak for themselves, and I’ll let the below figure tell the story:
Figure 11: Bitcoin versus other industries — yearly energy use, in TWh
The main takeaway should be that Bitcoin is a rounding error in the global scheme of things, and from a carbon-intensity point of view, has significantly less emissions per kilowatt than finance, construction, healthcare, industry or the military, and will only improve further in time. My prediction still stands: Bitcoin’s carbon intensity will go from 280 g CO2 per kWh today, to around 100 g in 2026, and zero by 2031, and maybe, finally, we’ll be done with this debate.”
This is a guest post by Hass McCook. Opinions expressed are entirely their own and do not necessarily reflect those of BTC Inc or Bitcoin Magazine