CO2 footprint such as Jordan or Hamburg: The cryptocurrency Bitcoin now requires around 46 terawatt hours of electricity per year for its computing operations. To meet this energy demand, around 22 megatons of carbon dioxide are released annually, as revealed by the most detailed study to date on Bitcoin’s energy balance. The CO2 footprint of the cryptocurrency thus corresponds to that of a small country or the city of Hamburg.
Crypto currencies are in vogue, because thanks to the blockchain principle, financial transactions can be processed decentrally and still securely via Bitcoin, Ethereum and Co. The catch, however, is that the necessary computing processes are complex and “Bitcoin mining” therefore consumes a lot of energy – and the trend is rising. Because the crypto calculations to be solved are constantly becoming heavier, the computing power required for a Bitcoin has quadrupled in 2018 alone. IPO and mining pool as data source
How much electricity the Bitcoin network needs and what CO2 emissions it causes as a result, researchers have already tried to determine. However, the large Bitcoin miners in particular have so far only revealed scant data about their investments. But the IPO of three major manufacturers of mining hardware in 2018 has now offered Christian Stoll from the Technical University of Munich and his team the chance to gain more insight.
From the documents submitted to the IPO, the researchers determined the market shares and energy efficiency of the individual computer models of Bitmain, Ebang and Canaan. In order to be able to calculate the power consumption more accurately, they included the size and type of Bitcoin investments: “The range ranges from students to gamers who make their graphics card available for Bitcoin mining during game breaks to specialized cryptomining farms,” Stoll and his team explain.
While smaller, private Bitcoin miners only need power for their computers, large facilities have additional energy consumption for cooling, transformers, and other ancillary equipment. In order to determine the proportions of the different types of miners, the scientists analyzed, among other things, the distribution in the Slushpool, a public association of various Bitcoin miners.Power consumption of 46 terawatt hours
The result: In November 2018, the annual electricity consumption of the Bitcoin network was around 45.8 terawatt hours – if one assumes the lower limit of the possible range. To meet this demand, more than five large power plants have to run at full load throughout the year. Since 2016, energy consumption has also risen relatively steadily, from 345 megawatts at the end of 2016 to 5,232 megawatts at the end of 2018, as the researchers calculated.
But how does this affect the CO2 footprint of the Bitcoin system? To clarify this, the researchers determined in which countries the computers of the Bitcoin miners are located and what the energy mix of the power grids looks like there. They located the location of the mining facilities both via the IP addresses in the statistics of the two largest pools and via special software that tracks down the IP addresses of the nodes that add a new block to the Bitcoin blockchain.68 percent of the computing power is in Asia
The evaluation showed: 68 percent of the computing power in the Bitcoin network is concentrated in Asia – especially in China. There, a good half of the mining facilities are located in the hydropower-powered south of China, but the rest work in northern China, where coal power supplies a large part of the energy. For the CO2 footprint of Bitcoin miners in China, the researchers thus come to a balance of 550 grams of CO2 per kilowatt hour of electricity consumed.
Another 17 percent of the computing power of Bitcoin miners is in Europe, 15 percent in North America, as Stoll and his team report. They also determined the CO2 footprint from the electricity mix of these regions.CO2 footprint like Hamburg
Overall, the researchers come to the conclusion: The Bitcoin system causes between 22 and 22.9 megatons of carbon dioxide per year. “This corresponds to an amount that lies between the CO2 emissions of Jordan and Sri Lanka,” stoll and his colleagues say. “The CO2 equivalent of Bitcoin is thus in the list of global emitters between rank 82 and 83.” In Germany, this value would be comparable to the CO2 footprint of the city of Hamburg.
“Even if there are more significant factors for climate change, the CO2 footprint is so large that it provides reason enough to discuss the regulation of crypto mining in locations with CO2-intensive electricity production,” says Stoll. The scientists plead for the mining facilities of Bitcoin and other crypto currencies to be relocated even more strongly in the future to where sufficient electricity from renewable energies is available.
There are already Bitcoin miners who, for example, consciously rely on “green” electricity from hydropower or wind energy. (Joule, 2019; doi: 10.1016/j.joule.2019.05.012)
Source: Technical University of Munich
– Nadja Podbregar
