Is Bitcoin Mining Really Greener? Here's What's Going On

Bloomberg’s new and optimistic research note on Bitcoin mining’s green energy mix is missing a key detail, according to an industry expert.

In his note, Bloomberg Intelligence analyst Jamie Coutts argued that the power used by the industry is now more than 50% green. He cited data showing Bitcoin’s declining carbon emissions since 2021 versus its rising hash rate, a measure of network security and mining activity. His conclusion: It could “only mean” the industry’s sustainable energy mix is growing larger.

Much of Bloomberg’s data was based on research from Daniel Batten, a climate-tech VC focused on using mining to clean up the atmosphere. However, Batten says this particular claim is only “partially correct.”

“It's a combination of both increased machine efficiency and more sustainable energy mix; particularly the drop in emissions intensity,” Batten told Decrypt.

Emissions intensity refers to the amount of carbon dioxide emitted per unit of electricity consumed by the Bitcoin network.

According to Batten, this metric may decline for two reasons: rising sustainable energy sources or more efficient mining rigs. Other events significantly reducing coal-powered Bitcoin usage—including China’s mining ban, Kazakhstan’s loss of miners, and Marathon reducing its mining activity in Hardin, Montana—also factor into the drop.

Estimating Bitcoin’s carbon emissions and overall power draw remains a developing science. Last month, Cambridge updated its Bitcoin Mining Index (CBECI) to better factor in the rising efficiency of ASIC machines, bringing down Bitcoin’s 2021 electricity consumption figures by 14%.

Confounding matters further is the presence of off-grid mining, which is tough to measure. Batten attempts to account for such miners in his own estimates of Bitcoin’s energy mix, placing the figure above 53%.

The VC believes four factors mainly contribute to Bitcoin greenification: More off-grid renewable miners, miners transitioning to sustainable sources, more mining using the Texas grid, and less mining in Kazakhstan.

Kazakhstan-based miners now account for approximately 1.5% of global hashrate according to Bitriver.” he noted, way down from 18% in October 2021. Bitriver is a hosting provider for green cryptocurrency mining.