【英語学習　ビットコイン】　ビットコインの電力消費を他の電力使用と比較する

Cambridge Bitcoin Electricity Consumption Index

Comparisons
Most people don’t have to deal with electricity figures in their daily life. As a result, they may find it difficult to put Bitcoin’s energy footprint into proper perspective. The goal of this page is to make Bitcoin’s electricity consumption more tangible and meaningful for a diverse audience by comparing it to other uses of electricity.

However, visitors should note that all comparisons face three major limits:

1. Apples and oranges
There is nothing quite like Bitcoin that can be readily used for an apples-to-apples comparison. Bitcoin is many things to many people: some consider it a new store of value in the form of a synthetic, counterparty-free commodity; others prize the underlying value transfer system that enables both payment and settlement functions in a permissionless and censorship-resistant fashion; and still others are primarily drawn to the incorruptible notary function enabled by its tamper-resistant public ledger. As a result, direct comparisons to other activities that appear similar on the surface can only provide a partial – and thus necessarily incomplete – picture.

2. Limited data availability
It is surprisingly challenging to find reliable electricity figures about the energy footprint of many industrial and residential activities. Datasets are often non-standardised, produced or maintained by various stakeholders who pursue different interests, based on distinctive theoretical models that use widely differing methodologies and assumptions, and/or limited to a specific geographic area or time period. This leads to conflicting estimates about the same activity that can stand in stark contrast to each other.

3. Presenter bias
Comparisons tend to be subjective – one can make a number appear small or large depending on what it is compared to. Without additional context, unsuspecting readers may be drawn to a specific conclusion that either understates or overstates the real magnitude and scale. For instance, contrasting Bitcoin’s electricity expenditure with the yearly footprint of entire countries with millions of inhabitants gives rise to concerns about Bitcoin’s energy hunger spiraling out of control. On the other hand, these concerns may, at least to some extent, be reduced upon learning that certain cities or metropolitan areas in developed countries are operating at similar levels. In practice, however, such a balanced approach is often impractical due to the difficulty of finding reliable comparative datasets.

Note: All comparisons below are based on our best-guess estimate. The listed comparisons are for illustrative purposes only and do not constitute an endorsement nor any other form of value judgment. We aim to continually update this page with relevant and applicable comparisons. This is an ongoing iterative process. We are always open to feedback, comments, and suggestions for new comparisons or reliable data sources – please contact us here.

Total World Production & Consumption
First, we consider Bitcoin’s share of the world’s total yearly electricity production and consumption. A reference to global energy production and consumption has been added as well to account for the wide array of industries that primarily rely on sources other than electricity (e.g. diesel fuel). In a similar fashion, some Bitcoin mining facilities are known to directly tap into energy assets at the production point rather than procuring electricity via the regular grid.

*Electricity is generated by transforming primary energy sources into electrical power. A significant share of the input energy is lost during this conversion process, with the exact proportion depending on fuel type and power plant efficiency. For simplicity, we assume an average conversion loss of 61% based on a 2020 study by the US Energy Information Administration (EIA) on the 2019 US electricity flow.

Sources
International Energy Agency, World Energy Balances (2020), 2018 est.
International Energy Agency, Key World Energy Statistics (2020), 2018 est.
International Energy Agency, Electricity Information (2020), 2018 est.

Industrial & Residential
Next, we set up Bitcoin mining against other industrial and residential uses of electricity (or energy, depending on the nature of the activity).

Bitcoin’s closest and most referenced real-world analogue is gold. While they arguably share utilitarian similarities as stores of value, gold and Bitcoin also demonstrate common consumptive traits, (e.g. the proportional relationship between unit price and increased production resulting in increased resource consumption).

Source
Mudd, G., Global trends in gold mining: Towards quantifying environmental and resource sustainability (2007), 2019 est. based on own calculations

Note: energy intensity estimates of gold mining on a global scale are difficult to verify and can vary considerably. This figure is based on an older estimate from 2006 which may not be representative of the state of the gold mining industry today. It nevertheless provides a useful input for modelling a simple baseline scenario that assumes little infrastructural upgrades in gold mines over the last decade.

As the set of suitable comparisons with qualitatively similar activities is very limited, we now turn to other uses that have less – or indeed very little – in common with Bitcoin other than being energy-intensive in their own right. These comparisons should thus be considered from a quantitative rather than qualitative viewpoint. We distinguish between industrial (raw material production) and residential uses (appliance or equipment utilisation).

Unlike other industries, Bitcoin mining is relatively mobile. In their quest for cheap and abundant energy sources, miners can set up new facilities fairly quickly all over the world, including the most remote areas (in fact, you can visually track these seasonal mining migrations with our mining map). As a result, Bitcoin miners can tap into so-called ‘stranded’ energy assets that cannot easily be put to productive use by other industries. In those cases, Bitcoin miners are not competing with other industries or residential users for the same resources, but instead soaking up surplus energy that would otherwise have been lost or wasted.

Instances of this ‘non-rival’ approach has been observed, among others, with renewables curtailment in China (primarily hydro as a result of excess capacity during the wet season) as well as gas flaring in North America (turning natural gas from an undesirable by-product of oil extraction into a valuable commodity).

Country Ranking
Country comparisons are, for better or for worse, the most common type of comparison. They are frequently used in the public debate to support positions of concern about the scale of Bitcoin’s electricity consumption.
Source
U.S. Energy Information Administration, Country Data, 2019 est. (or most recent available year)

However, as indicated by the chart below, country comparisons without additional context provide only limited insight given the huge disparities between nations. The size of a country, both in geographical and population terms, does not always correlate with energy usage. Instead, the energy profile of each country is a unique product of factors such as the energy demand of domestic industries and residents, the level of economic and social development, the stock of available energy sources, economic spending and production patterns, strategic policy actions to attract or outsource energy-intensive industries, and many more. As a result, it should not be surprising that the energy footprint of a single large city in a developed country can match the total level of an emerging economy.

Fun Facts
We would like to end this brief excursion on a more amusing note, with a wink to our parent institution and a dearly held British tradition.

Did you know that the amount of electricity consumed by the Bitcoin network in a single year…

Sources
University of Cambridge, Facts & Figures | Sustainability (2021), 2017/18 est.
Drysdale, B. et al, Flexible demand in the GB domestic electricity sector in 2030 (2015), 2012 est.