Featured Article: Energy – Consumption & Carbon From Bitcoin and Other Tech

With the news that mining Bitcoin uses more electricity annually than the whole of Argentina, we take a closer look at the carbon footprint of technology today.

Cambridge

Researchers from Cambridge recently highlighted how power-hungry “mining” for the Bitcoin cryptocurrency is because it requires heavy computer calculations to verify transactions.  The researchers reported that it consumes 21.36 terawatt-hours (TWh) a year meaning that if Bitcoin were a country, its energy (electricity) consumption it would be ranked above Argentina and the energy could power all the kettles in the UK for 27 years!

Mining

Bitcoin “mining” is the activity that uses the energy. Mining refers to needing to have specialised Bitcoin computers that are constantly on and connected to the cryptocurrency network to verify transactions (sending and receiving of Bitcoin).  This verification is achieved by the computers solving puzzles to prevent fraud and to win small amounts of Bitcoin. The whole process is extremely energy-hungry.

Greater Popularity Means More Power Consumption

Bitcoin has received some boosts in its popularity recently which have resulted in a boost in buying activity with the cryptocurrency, and consequently, an increase in its energy consumption.

For example, most recently, Elon Musk’s EV company Tesla bought $1.5bn of Bitcoin, which encouraged a surge in other investors.  Also, PayPal now allows US customers to buy, sell and hold bitcoin (and other tokens) in their online wallets, Square bought $50m in bitcoin in October because of its perceived future growth potential, and major banks (e.g. European Central Bank) considering getting into cryptocurrencies. There has also been more speculation from investors seeking safety after an uncertain year at the hands of COVID-19 and its effects on the global economy.

All these factors have meant a rise in the value of Bitcoin which has attracted Bitcoin miners to run more machines and, therefore, consume more energy with the effect of creating larger quantities of damaging CO2.

Perspective

Although Bitcoin mining may be good news for energy companies and bad news for the environment due to current contribution to excess CO2 production, there are other areas that are often overlooked where huge improvements in excess energy consumption could be made by relatively small changes.  For example, the amount of electricity consumed each year by home devices in the US alone that are always-on but not active could power the entire Bitcoin network for a year.

Leaving devices on standby (e.g. the television and phone chargers plugged in and switched on) has long been known to be a source of wasted energy, CO2 pollution, and higher bills.  For example, the Energy Saving Trust believes that an average UK home wastes between £50 and £86 each year by leaving appliances on standby.

Simple changes such as putting a computer in sleep mode rather than letting it stay constantly in screen saver mode when it’s not being used (which can take up more energy than actually using the computer) can save a lot of energy and contribute to the reduction of carbon emissions.

Even Google Searches

Back in 2009, there were reports that performing two Google searches from a desktop computer could generate roughly the same amount of carbon dioxide as boiling a kettle (i.e. around 7g of CO2 per search).  This was a newspaper report (Sunday Times) which, after further consultation with Google was revised to say that it did not refer to a one-hit Google search taking less than a second, which Google agreed produced about 0.2g of CO2.

And Emails….

In November 2020, a Financial Times report based on work by Tim Berners-Lee and Ovo Energy highlighted how sending fewer emails could help tackle climate change by reducing carbon emissions. The report suggested that sending emails uses a lot of energy and produces carbon.  This is because in order to allow emails to be written and sent, energy must be used by servers, home wi-fi, and a laptop.  Also, the carbon emitted to construct data centre buildings could also be taken into when assessing the environmental impact of email as this represents significant greenhouse gas (carbon) production.  The report estimated that although each individual email is likely to be responsible for producing an incredibly small amount of carbon as a proportion of the 435.2 million tonnes of greenhouse gasses produced by the UK in 2019, there is likely to be a cumulative impact. This impact is likely to be made greater by the sending of “unnecessary” emails.

For example, Ovo Energy commissioned (Censuswide) research shows that the 64 million “unnecessary” emails sent every day could be responsible for contributing 23,475 tonnes of carbon a year to the UK’s carbon footprint. Unnecessary emails are categorised as those sent to friends within talking distance, or those containing replies such as ‘thank you’, ‘thanks’, ‘received’, and similar.

There is, of course, the argument that whether sending emails or not, having laptops, computers, Wi-Fi routers (and more) switched on all the time is contributing to the production of carbon and that separating out the individual contribution of emails is difficult. It could also be argued that game and video streaming and cloud storage have more of a negative impact than sending emails.

Data Centres

The huge and growing demand for Internet and mobile phone traffic and the increasing reliance on the Cloud has led to more data centres being built by big tech companies. It is estimated that data centres use 200 terawatt-hours (TWh) per year which is more than the energy consumption of some countries e.g., Iran, but only 1 per cent of global electricity demand. In terms of their carbon footprint, data centres contribute around 0.3 per cent to overall carbon emissions.  That said, Hyperscale data centres, which emerged about a decade ago, are reported to have kept electricity demand at roughly the same level due to becoming super-efficient and the stripped-down, bare-bones servers.

Apple Reports Fully Renewable Energy Data Centres

Back at the end of 2018, Apple reported that it had hit a new milestone in green energy usage by making all of its 43 data centre sites across the world operate using 100 per cent renewable energy. What that meant was that the data centres could be 100 per cent ‘renewables powered’, due to the ‘clean energy’ that Apple was buying and putting back into the power grid that could be offset against its global power consumption.  Apple reported that this had been achieved by six years of financing, building, or locating new renewable energy sources (e.g. solar and wind farms) near the company’s facilities. In 2018, Apple said that it had 25 operational renewable energy projects, and 15 more in construction, spread across 11 countries.

There was some criticism at the time, however, when it was pointed out that the manufacturing of iPhones, iPads and other machines creates carbon emissions.

ICT

The whole information and communications technology (ICT) ecosystem, which encompasses personal digital devices, mobile-phone networks, and televisions, has been estimated to account for more than 2 per cent of global carbon emissions which makes its carbon footprint the equivalent of the aviation industry’s emissions from fuel (prior to the pandemic).

Looking Ahead

It appears that our need for smart devices, the Internet and electricity is only going to increase. Making devices and data centres that are much more energy-efficient, switching more to green energy, and carbon offsetting are some ways that the tech industry is trying to limit its carbon footprint.  Also, Carbon Capture Systems, such as the ones recently highlighted by Elon Musk’s offer of a $100M prize are another way that harmful carbon, such as that produced by the ICT ecosystem could be physically removed from the atmosphere, but there is still some way to go on this.  For now, it is unlikely that most people will think about the environmental impact of Bitcoin mining and some commentators have pointed to the need for a carbon tax on cryptocurrencies to help balance out some of the negative consumption.  It is also unlikely that with businesses trying to recover from the pandemic they are going to think about limiting how many emails they send.  The fact is, however, that businesses and individuals each have a responsibility to take what measures they can to reduce their own carbon footprint and that governments are likely to continue using a combination of punishments and rewards to help us all meet the agreed environmental targets.