Study: 20MW wind Bitcoin mine losses persist if hashrate rises

Researchers at the Technological University of the Shannon modeled a 20 MW Bitcoin mining operation tied to a hypothetical 100 MW Irish wind farm using 2024 hourly Irish market data. The model tested wind curtailment scenarios from 5% to 25% and assumed a six‑year equipment life, perfect foresight on future prices and an Irish private‑wire regulatory framework that has not yet been finalized.

The 20 MW mine captured 83.1% of the wind farm’s annual dispatch‑down energy in the model, increasing total system revenue from €22.2 million to €29.2 million, a 32% rise. Scaling the mine to 30 MW increased absorption of curtailed power to 93.4% and lifted system revenue to €31.1 million. The researchers reported diminishing revenue gains and higher hardware costs for installations larger than 30 MW.

Profitability varied by Bitcoin price and curtailment level. At €100,000 per bitcoin the modeled 20 MW project returned investment in roughly 2.13 to 3.56 years across curtailment cases. At €80,000 per bitcoin payback extended to about 3.44 years at 25% curtailment and 4.07 years at 20% curtailment, while lower‑curtailment scenarios did not meet the six‑year window. At €60,000 per bitcoin none of the tested curtailment levels showed payback within six years. Bitcoin’s market price is currently below the study’s lowest tested price.

The study’s central sensitivity analysis compared compound annual Bitcoin price growth with global hashrate growth. Points where price and hashrate grew at the same annual rate produced an identical six‑year net present value of negative €10.1 million, equal to a negative 5.7% return. That result held when both variables increased at 5%, 15% or 30% per year. The model produced a positive six‑year NPV only when Bitcoin’s compound growth significantly outpaced hashrate growth; for example, Bitcoin compounding at 30% annually while hashrate compounded at 15% yielded a six‑year NPV of €7.7 million, while Bitcoin at 30% versus hashrate at 25% returned negative €5.1 million.

Hardware efficiency affected outcomes. Older Antminer S9 machines, at roughly 98 joules per terahash, were uneconomic across the modeled 2024 scenarios. Viable cases in the study relied on newer Antminer S21 Hydro‑class hardware at about 16 joules per terahash.

The researchers fixed network hashrate at 780 exahashes per second for primary scenarios. Recent moving averages of network hashrate used for directional comparison were around 911–914 EH/s. The report cited a spot hashprice of about $31.73 per petahash per day, a level described as at or below breakeven for many miners depending on costs and hardware. The next block subsidy halving in 2028 falls inside the model’s six‑year equipment life and would reduce miner revenue when it occurs.

The study also noted growing demand for low‑cost power from non‑mining customers. The report cited a 20‑year, 191 MW lease to an AI lab with an estimated value of $9.1 billion over the initial term and industry estimates that cumulative AI and high‑performance computing contracts to public miners exceed $70 billion. Under the study’s stated assumptions, researchers report that a scenario combining sustained Bitcoin price growth that outpaces hashrate, efficient modern hardware and access to genuinely stranded power produced positive NPV within the six‑year equipment window.