Bitcoin and the Future of Sustainable Energy

Golden bitcoin and green plant in soil

As awareness of Bitcoin has grown, so too have concerns about its energy usage. In this note we take a look at the scale and composition of Bitcoin’s energy consumption, show how Bitcoin miners are already acting as marginal buyers for stranded energy producers, and explore how Mawson is working to make Bitcoin mining a key part of our clean energy future.

Highlights
  • Bitcoin’s current yearly electricity use is ≈90TWh1 per year. For comparison, gold mining uses about 131TWh, and the total amount of energy supplied globally in 2020 was 166,000 TWh2.
  • Bitcoin mining emits ≈25 Megatonnes (Mt)3 of greenhouse gas (GHG) per year, equivalent to about 0.05% of the 48,9284 Mt of global emissions in 2018.
  • More than 75 percent of miners use renewable energy. By buying stranded or excess power, Bitcoin miners can support the transition to cleaner energy.
  • Mawson is accelerating this clean energy transition by developing Modular Data Centres that can be installed at the source of underutilised energy, improving the viability of solar and wind projects or making use of methane that would otherwise be vented.
The Mawson View

Mawson Infrastructure Group believes in the future of Bitcoin as a contributor to positive social, economic, and environmental change. Our commitment to the mining industry – one of the most volatile and competitive industries in technology – is testament to this faith.

We also recognise that investors are committed to ensuring that their portfolio aligns with their values. We have prepared this memo to address common questions that investors have about energy, emissions, and the environmental impact of Bitcoin in a global context.

We also hope to give insight into the nature of competition in the industry, Mawson’s position as an innovation leader, and what might be in store over the next decade.

A Primer on Energy, Electricity & Emissions
While all electricity is energy, not all energy is electricity. Of the 166,000TWh of global primary energy, only 26,823 TWh, or just over 15%, is consumed as electrical energy. The rest is used for transport, heating, or — in the case of roughly 30% of global energy usage — wasted. It’s this last category that Bitcoin miners have their sights set on. Energy that is currently wasted — either because it is not economical to transport, like methane vented during coal mining, or because energy infrastructure lacks the capacity to transport peak loads — can be purchased cheaply by miners.
Bitcoin Emissions in a Global Context
Bitcoin mining, in which pools of specialised computer hardware compete to produce a cryptographic hash of blocks of transactions, is computationally intensive. For many advocates of digital assets the benefits of a secure digital currency are worth the costs. But for others the value is less clear, especially in the context of climate change. While it is challenging to compare Bitcoin, which we see as the first of a new kind of asset class, to other sectors, this section provides an outline of the emissions profile of Bitcoin mining, drawing on recent research that compares the carbon-intensity of different industries. Estimates from 2019 place the total annual amount of Greenhouse Gas (GHG) produced by Bitcoin mining around ≈23 Mt CO2e, roughly equal to those produced by the country of Sri Lanka. While this is not insignificant, Bitcoin’s GHG footprint remains substantially smaller than those of other commodities like gold (145 Mt), and less than a third of just the fugitive emissions that are unintentionally released industrially (75 Mt). For scale, established industries like the finance and insurance industries are estimated to be responsible for 1,368 Mt of CO2 equivalent emissions. But this figure in isolation does not tell the story of whether Bitcoin is “clean” or not. A better metric for this is Carbon Intensity, or the amount of GHG emitted per kilowatt-hour of energy generated. The Intergovernmental Panel on Climate Change (IPCC) has published extensive data on Carbon Intensity6, and this is summarised in Figure 2.
Figure 1 - Bitcoin Emissions vs. Other Industries (McCook, 20217)
Figure 1 - Bitcoin Emissions vs. Other Industries (McCook, 2021) 7

As a result of recent shifts in the location of mining activity, the majority of Bitcoin’s energy is now coming from clean energy sources, and carbon intensity has dropped substantially below the global average.

Energy Mixes - Bitcoin vs. Global Grid vs. Global Primary Energy
Figure 2 - Energy Mixes - Bitcoin vs. Global Grid vs. Global Primary Energy. Sources: CCAF8, OurWorldInData9, BMC10

Bitcoin is 65% less carbon intensive than the world’s primary supply, and 40% less intensive than the world’s electricity grid.

Bitcoin’s Energy Use in a Global Context
Bitcoin’s energy mix incorporates a significant amount of low-emission and renewable energy, but on its own this might do little to reassure those concerned that this energy might be best used elsewhere. Recent estimates suggest that global Bitcoin mining operations use between 9011 and 190 TWh of power12 (the higher end factors in estimates of energy wasted during production and transport). 190 TWh equates to around a tenth of one percent of world energy production.
Global Stranded and Curtailed Energy
Despite declining cost and increasing efficiency, renewable energy sources like wind and solar have yet to reach hoped-for levels of adoption. One major challenge for renewables is intermittency — while coal-fired power plants produce a predictable amount of energy over the course of a 24 hour period, solar farms produce power when the sun shines and don’t when it doesn’t. Moving to a renewable-powered grid also requires investment in new infrastructure — many of the best sources of renewable energy are located far from population centres. While Bitcoin is not a direct solution to underinvestment in energy infrastructure, Bitcoin mining has a number of properties that makes miners a particularly useful buyer of energy that might otherwise not be used. As producers of a commodity, Bitcoin miners are highly price-sensitive. Because of this, Bitcoin mining tends to take place where energy is cheapest and most readily available. Secondly, unlike many other economic activities, Bitcoin mining has no start-up costs or warm-up time and is therefore highly interruptible. This means that miners can quickly come online in response to excess energy supply, and then quickly turn-off again when demand returns. These two properties make Bitcoin mining a useful partner for renewable energy sources like wind and solar, that suffer from demand-supply mismatches. By providing a buyer of last resort for marginal producers, Bitcoin has the potential to enable otherwise uneconomic renewable projects without additional investment in grid infrastructure or battery storage. These properties also allow Bitcoin miners to make use of other sources of ‘stranded’ energy that would be wasted, like the methane that is flared or vented by coal mines. As a greenhouse gas, methane has 25-100 times more warming potential than CO2. Piping it into a generator and mining Bitcoin prevents the methane from being vented into the atmosphere, and also generates income. While it is difficult to tell how much waste methane is being used in this fashion, The World Bank estimates that 150 billion cubic meters of gas (approx. 1,536 TWh of energy) is flared yearly13 – enough to power Bitcoin ten times over.
Mawson as an Innovation Leader

At Mawson Infrastructure, we believe that Bitcoin can contribute to a future in which we can provide clean, sustainable and abundant energy for everyone. Our focus is on building the technology that will accelerate this process.

Innovation starts with people, and it is through our innovative spirit that we have built a business around the development of a mining solution that can go anywhere in the world, with investment-grade reliability and uptime. Our Modular Data Centres (MDCs) provide state-of-the-art mining technology in a modular, highly mobile form that can go wherever it’s needed.

By employing cutting edge techniques, like Liquid Immersion Technology (LIT), in the design of our MDCs, we have been able to dramatically increase their efficiency, footprint and resilience. Modularity is not just a matter of convenience — for Mawson, mobility is critical for positioning Bitcoin mining as a flexible buyer of last resort for renewable energy producers.

Footnotes

[1] Cambridge Centre for Alternative Finance, August 2021, “Cambridge Bitcoin Electricity Consumption Index”, www.cbeci.org

[2] International Energy Agency, 2020, “Key World Energy Statistics 2020”, page 6, bit.ly/3B4q1nR

[3] McCook H., 2021, “Bitcoin’s Energy Use Compared to Other Major Industries”, bit.ly/3B4C4Bu

[4] World Resources Institute, 2021, “CAIT Data Explorer”, bit.ly/3kmVryW

[5] BP, 2021, “BP Statistical Review of World Energy”, 2021, page 63, on.bp.com/3zfufsi 

[6] Intergovernmental Panel on Climate Change, 2012, “Renewable Energy Sources and Climate Change Mitigation”, page 190, bit.ly/3gtB168

[7] McCook H., 2021, “Bitcoin’s Energy Use Compared to Other Major Industries”, bit.ly/3B4C4Bu

[8] Cambridge Centre for Alternative Finance, 2020, “3rd Global Cryptoasset Benchmarking Study”, pages 26-28, bit.ly/3ydVl1A

[9] University of Oxford, 2021, “OurWorldInData – Global Primary Energy Consumption by Source”, bit.ly/3ybXGKf

[10] Bitcoin Mining Council, 2021, “Global Bitcoin Mining Data Review – Q2 2021”, slide 6, bit.ly/3DgoPiY

[11] McCook H., 2021, Bitcoin’s Energy Use Compared to Other Major Industries, bit.ly/3B4C4Bu

[12] Bitcoin Mining Council, 2021, “Global Bitcoin Mining Data Review – Q2 2021”, slide 7, bit.ly/3DgoPiY

[13] World Bank, 2020, “Global Gas Flaring Tracker Report”, bit.ly/2XMwTYw

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