बिटकॉइन बनाने में जितनी बिजली खर्च होती है, उससे मुंबई जैसे बड़े महानगर की बिजली की जरूरत पूरी की जी सकती है। बिटकॉइन का सालाना कार्बन फुटप्रिंट मुंबई के बराबर है। दुनिया के संदर्भ में देखें तो यह स्लोवाकिया के बराबर है। डच इकनॉमिस्ट एलेक्स डी व्रीज (Alex de Vries) की एक स्टडी के मुताबिक बिटकॉइन से हर साल 38.10 एमटी (मिलियन टन) कार्बन फुटप्रिंट पैदा होता है। एक स्टडी के मुताबिक मुंबई का कार्बन फुटप्रिंट करीब 32 एमटी और बेंगलोर का 21.50 एमटी है। हाल में माइक्रोसॉफ्ट के को-फाउंडर बिल गेट्स ने हाल में एक इंटरव्यू में कहा था कि बिटकॉइन में प्रति ट्रांजैक्शन जितनी बिजली खर्च होती है, उतनी किसी और में नहीं होती है।
Relation between creating bitcoins and electricity required
Bitcoins are created by “mining” coins, for which high-tech computers are used for long hours to do complex calculations. The more coins there are in the market, the longer it takes to “mine” a new one and in the process, more electricity is consumed. As mining provides a solid source of revenue, people are willing to run power-hungry machines for hours to get a piece.
In 2017, the Bitcoin network consumed 30 terawatt hours (TWh) of electricity a year. However now, according to de Vries’s estimates, the network currently uses more than twice as much energy: between 78TWh and 101TWh, or about the same as Norway. As such, each bitcoin transaction roughly requires an average 300kg of carbon dioxide – which is equivalent to the carbon footprint produced by 750,000 credit cards swiped.
If Bitcoin were a country, it would consume more electricity than Austria or Bangladesh.
Calculating the carbon footprint
The major problem with mining Bitcoin is not its massive energy-consumption nature, it is the fact that most of the mining facilities are located in regions that rely heavily on coal-based power.
Earlier, determining the carbon impact of the Bitcoin network was difficult as tracking down miners was never easy. However, in 2017, a study by Garrick Hileman and Michel Rauchs identified these facilities and calculated consumption of 232 megawatts a year. As per the estimates of De Vries, roughly 60% of the costs of bitcoin mining is the price of the electricity used. In January, the price of a Bitcoin stood at $42,000 and at this rate, miners would be earning around $15 billion annually.
“With 60% of this income going to pay for electricity, at a price of $0.05 per kWh [kilowatt hour], the total network could consume up to 184TWh per year,” De Vries wrote in his study.
The paper cites an assumption of 480-500g of carbon dioxide produced for every kWh consumed. That would mean a total energy consumption of 184TWh would result in a carbon footprint of 90.2 million metric tons of CO2, which is roughly comparable to the carbon emissions produced by London.