The social cost of bitcoin mining in BC

Bitcoin mining consumes copious amounts of electric power worldwide, with a related out-sized environmental impact. Each bitcoin transaction requires processing through the network of bitcoin miners that maintain the distributed ledger and are in a race to earn the next bitcoin as compensation for their effort. This race to earn the next bitcoin is known as "proof of work". Other crypto-currencies, such as Ethereum, use an alternative method known as "proof of stake" that requires little electricity.

Cryptocurrency mining farm. Copyright iStockPhoto.

Image licensed by iStockPhoto.

There are about a dozen bitcoin miners active in BC, but in December 2022, British Columbia introduced an 18-month moratorium on new bitcoin mining ventures due to the expected large impact on the provincial electricity grid.

‘Bitcoin mining caused worldwide emissions of about 86 million tonnes of carbon dioxide last year (in 2023).’

Estimates for the worldwide use of electricity for bitcoin mining range between 100 and 200 Terawatthours [TWh]. That is roughly the amount of electricity consumed by entire countries, with Belgium at the lower end and Egypt at the upper end. Some estimates are even higher, suggesting that worldwide bitcoin mining could consume as much electricity as Australia. In 2021, The New York Times provided an analysis that explains why bitcoin mining uses more electricity than many countries. Reliable estimates such as the Cambridge Bitcoin Electricity Consumption Index point to about 170 TWh/year annual electricity use. All that electricity use comes with a hefty environmental footprint because generating electricity uses fossil fuels in many of the places where bitcoins are mined. Estimates (also from the CBECI) suggest annual emissions of about 86 million tonnes of carbon dioxide (MtCO2e), assuming an average mix of electricity generation worldwide. In the worst case, if bitcoin mining relies much more on coal power at the margin, this total could double.

So what is the true cost of mining another bitcoin, and how does it compare to the revenue from mining another bitcoin? Prices for one bitcoin have varied between USD 30,000 and 50,000 over the course of last year (2023), so mining one bitcoin will result in revenue equal to a price in that range. It is estimated that mining one bitcoin requires about 260 Megawatthours [MWh], including cooling services for the server farms. The cost of electricity in BC for large general service, $0.0614/kWh, implies a "production cost" of just USD 11,000 per bitcoin—enough to make a profit for the bitcoin miners. If the bitcoin miner is subject to the medium general service rate (currently $0.0981/kWh), the cost would be USD 17,600.

Note that these numbers are changing each time the bitcoin system encounters a "halving" event when producing the next bitcoin will take twice as much effort. The next halving is expected in 2024. This "halving" process is meant to ensure that there will never be more than 21 million bitcoins in total. The consequence of this approach is that the cost of bitcoin mining will rise steadily.

‘Mining bitcoins should face the full social cost of carbon, estimated as USD 24,000 per newly-mined bitcoin.’

But the social cost of bitcoin mining is much higher than the private cost because of the environmental consequences. Mining a new bitcoin can be associated with about 500 grams of CO2 per kilowatthour, roughly the global emissions from electricity generation. This means that mining one new bitcoin is responsible for releasing 130 tonnes of carbon dioxide. At BC's current carbon price of $65/tonne, this would come to $8,450. However, the social cost of carbon is calculated by the Government of Canada as $266/tonne for 2024. So the environmental damage from mining one bitcoin is worth about $34,580, or about USD 24,000. Adding the environmental cost of bitcoin mining to the electricity cost of bitcoin mining would make bitcoin mining unprofitable in British Columbia if the price for one bitcoin falls below USD 35,000.

BC-based bitcoin miners will argue that using hydro electricity in BC is much cleaner than the world average, and thus they should not pay a carbon price at all. But that argument is a fallacy because it assumes that bitcoin mining takes place exclusively in BC. Every bitcoin transaction leads to bitcoin mining activity worldwide, and thus a bitcoin miner in BC is responsible for the worldwide race to earn the next bitcoin. Mining one "cleaner" bitcoin in BC does not displace mining one "dirtier" bitcoin somewhere else, because the winner of the bitcoin mining race is probabilistic. Bitcoin miners collectively are responsible for their worldwide CO2 emissions and should pay the price. Whichever bitcoin miner wins the race to earn the next bitcoin is responsible for all the emissions, including the losers of that race in other (dirtier) jurisdictions. As the common German saying has it: mitgefangen, mitgehangen—if you get caught together with them, you get punished together with them. If the bitcoin mining industry is to be treated just like any other industry, it needs to first face up to its full environmental cost.

‘The full social cost of mining a Bitcoin in BC exceeds CAD 79,000.’

BC's lowish electricity rate for large general service (just about six cents per kilowatthour) is not designed for adding vast new demand to the system. Consider the levelized cost of electricity (LCoE) of BC's new site-C dam, which is expected to come online in January 2025 and is reckoned to cost about $16 billion. Fully amortized, Dolter, Fellows, and Rivers (2022) calculate the LCoE of Site-C dam as $170/MWh. While this is not the cheapest option for expanding BC's electricity grid, it is what is coming online as new capacity. Thus the price for large new connections should reflect that, and be at least $0.17/kWh. At that price, mining a new bitcoin in BC would cost at least USD 30,500. Add to this the social cost of carbon of USD 24,000, and the full social cost of mining a new bitcoin in BC exceeds USD 54,500 or CAD 79,000. This calculation does not even include the private cost of amortizing the computer hardware, buildings, taxes, labour, and other operational expenses. Thus CAD 79,000 is better thought of as the "floor" for the full social cost of bitcoin mining in BC. In any case, if bitcoin miners were to pay the full social cost for their activity, bitcoin mining would not be profitable in BC.

In light of the recent ruling by the BC Supreme Court in the case of Connifex Timber Inc. v. British Columbia (Lieutenant Governor in Council), what can the Province do to curtail the expansion of bitcoin mining permanently? As the ruling by Judge Tammen explains, the application for grid access by the bitcoin miner—a lumber firm turned crypto-miner—is in a class of its own because it asked for essentially half of the output from Site-C dam, about 2.5 TWh. The Province has an 18-month moratorium in effect prohibiting access to the grid from new bitcoin miners, but this moratorium is due to expire in May of 2024. The Province could either extend the moratorium or amend the Utilities Commission Act (UCA) to expand BCUC's mandate to expand the scope of the public interest expressed in section 28(3) of the UCA. What constitutes "public interest" should be clarified, and the scope of 28(3) needs to cover a "class of similar applicants" to avoid hearing the same case again and again by similar applicants. What is perhaps needed is a clause that stipulates: "After a hearing and for proper cause, the commission may relieve a public utility from the obligation to supply service under this Act to a single party or to a class of similar parties on terms the commission considers proper and where the public interest involves:

  1. protecting the stability and resilience of the electricity generation and distribution system, including the ability to meet peak demand;
  2. ensuring the affordability of service for all utility customers;
  3. giving full consideration to opportunity costs of alternative uses of electricity including exports to other jurisdictions;
  4. preventing foreseeable and undue harm to public health and safety;
  5. preventing foreseeable and undue harm to the environment;
  6. prioritizing public policy goals, which are expressed by applicable legislation or by an Order in Council, over the private interests of parties where providing service to private parties, or a class or private parties, would unreasonably interfere with achieving the express public policy goals."

I trust that government lawyers will be able to express these notions more precisely and cogently. But essentially, the Province has a political prerogative to define what is, and what is not, in the public interest, and elected officials are accountable to British Columbians through democratic elections.

In fact, there are well-established precedents where purposeful discrimination by utilities is in the public interest. For example, experienced motorists are eligible for lower insurance premiums than inexperienced motorists, as there is an actuarial basis for treating these groups differently. There is no reason why electricity users could not be treated similarly if they cause different levels of harm to society, as long as there is no within-group unfair discrimination. In turn, society may give benefits to some group of utility customers if doing so creates public benefits. BC Hydro's industrial electrification rates recognizes a specific CleanBC Industrial Electrification Rate that provides a rate discount to attract new businesses to BC. As I have made clear above, bitcoin mining is the exact opposite: the industry collectively contributes to global greenhouse gas emissions, and BC-based cryptominers are fully complicit ain the actions of their network partners worldwide. For that reason cryptocurrency projects are specifically exempt from the CleanBC incentives.

Alternatives to this regulatory approach are implied by the discussion above: raising the price of bitcoin mining in BC either through an explicit carbon price on the marginal global emissions from bitcoin mining, and/or creating a new rate class for utility customers who would significantly shift the utility's generating capacity and therefore need to reflect the marginal cost of adding new capacity. The environmental cost of mining one new bitcoin is essentially equal to a $0.133/kWh surcharge. Add this to the marginal cost of new capacity of $0.17/kWh, and an appropriate tariff rate for bitcoin miners calculates as $0.303/kWh. This is still awfully cheap by world standards; for example, retail customers in Germany currently pay $0.58/kWh (€0.40/kWh) for their electricity.

Cryptomining was banned in China in 2021. The resulting exodus of bitcoin miners has made bitcoin mining even dirtier, according to new research. Where has bitcoin mining gone? About a third of bitcoin mining appears to take place in the U.S. now, and one-tenth in Canada. Other major host countries for bitcoin mining are Kazakhstan and Russia.

Lastly, a word of caution to any current or prospective investor in bitcoins. Bitcoins are a speculative and extremely volatile asset without any intrinsic value. Bitcoin mining may cease if/when the cost of bitcoin mining exceeds the price of bitcoins. Bitcoin operations may also become subject to new regulations, prohibitions, or taxation in different jurisdictions. Caveat emptor!

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Posted on Thursday, February 8, 2024 at 05:45 — #Environment | #BC | #Energy | #Law | #Politics