Challenges, opportunities, and sustainability: analysis of the environmental impact of Bitcoin mining.
To fully grasp the dynamics involved in the Bitcoin’s environmental impact, it is necessary to understand the fundamental principles underlying the process of creating new bitcoins, known as mining.
Bitcoin mining is the activity through which transactions are validated and added to the blockchain. Miners, engaged in this operation, use high-powered computing devices known as ASICs, often housed in large data centers, to participate in the competition aimed at creating a new block in the blockchain.
Energy consumption of Bitcoin
Several studies have attempted to quantify the electricity consumed by Bitcoin over the years. One of the most well-known indices for calculating this consumption is the Cambridge Bitcoin Electricity Consumption Index (CBECI). However, as of August 2023, the estimates of this index have been revised downward, as highlighted in this report.
The Cambridge CBECI is not the only effort in assessing the energy consumption of Bitcoin. Daniel Batten, co-founder of CH4 Capital and an investor in climate-related technologies, has written several articles on the subject, reaching conclusions similar to those of the University of Cambridge. In his contribution, Batten asserts that the energy consumption of Bitcoin is at least 23.7% lower than the initial calculation made by CBECI.
The divergence in these estimates stems from the disparity in calculation methodologies: Batten’s study considers both on-grid and off-grid mining, while Cambridge has declared its focus exclusively on on-grid mining activity.
Off-grid mining activities are generally energetically independent of the national power grid or enter into specific contractual agreements with network owners. This methodological difference is substantial because in his BEEST study model, Batten argues that off-grid mining activities represent the majority of the global hash rate.
Sustainability and renewable energy
Companies involved in Bitcoin mining demonstrate a predominant interest in securing a supply of electricity at the lowest possible cost.
Following this logic, it is essential to explore sources of low-cost electricity. In most countries worldwide, the least expensive electricity is represented by surplus energy, often wasted as it is not adequately utilized. A miner is economically motivated to harness such energy sources due to their cost-effectiveness.
Electricity from renewable sources, particularly wind, hydroelectric, and solar power, constitutes another low-cost energy source. Therefore, over the past few years, the mining sector has undergone a significant transition from fossil fuel-based energy sources to cleaner alternatives. In fact, despite the continuous increase in the hash rate, emissions related to the production of electricity used in mining are decreasing.
Some mining farms actively seek regions with an abundance of renewable energy, such as hydroelectric power, harnessing the power of moving water to generate electricity characterized by a constant flow.
Furthermore, ongoing technological innovations, such as the adoption of more energy-efficient mining hardware, can contribute to mitigating the environmental impact of the sector.
Currently, the global electrical grid relies heavily on coal as the primary source of energy. This means that data centers, electric vehicles, gaming systems, dryers, household lighting, electric stoves, smartphones, computers, induction cooktops, and a myriad of other appliances and technologies are predominantly powered by coal. In contrast, Bitcoin relies on hydroelectric power as its main source of energy in its energy mix.
The potential to become carbon negative
The ability to harness otherwise unused energy sources means that miners are progressively focusing on the energy optimization of industrial processes such as oil extraction and landfill management.
According to studies conducted by Daniel Batten, it is plausible that Bitcoin could become carbon negative within a few years, thereby contributing to the reduction of CO2 emissions in the atmosphere. This achievement would be realized through the utilization of waste methane from landfills and oil extraction facilities in mining activities.
Currently, we are already witnessing this transformation, with some companies exploiting phenomena known as gas flaring and gas venting for Bitcoin mining.
According to Batten’s estimates in December 2022, the emissions saved in the atmosphere amounted to 2.2 gigatons (Gt) of CO2.
