New here?Quick start for Coal Mine Methane— typical inputs, what to ask the host, red flags
Typical inputs
Flow: 200–2,000 scfm at a borehole/gob-well manifold; concentration matters more than volume here.
CH₄ %: 25–95% CH₄ — extremely variable. Below 25% generally needs blending or enrichment to combust safely.
What to ask the host
- Borehole-by-borehole flow and CH₄ % over the last 12 months.
- Mine status — active, idle, or abandoned (AMM) — and gob-well age.
- Existing drainage infrastructure and any VAM oxidizer in place.
- MSHA / state safety constraints on engines underground or on the bench.
Red-flag inputs
- Assuming peak concentration as the design point — sizing for the average is safer.
- Ignoring CH₄ slip in safety calculations as concentration drops.
- Treating abandoned-mine methane like active CMM for additionality.
Full walkthrough on the Guide. Formulas live in the Glossary.
CMM → Hash · Feasibility · Beta v0.9
Coal Mine Methane to Hash Feasibility
Capture methane drained from active or abandoned coal mines (CMM/AMM/VAM-adjacent) and convert it to mining instead of venting.
Gas Specification
Drained gas at borehole/gob well manifold
CMM is typically very low H₂S
Generator Configuration
Typical range: recip 32–40%, microturbine 26–33%
Parasitic & Cleanup Loads
Operational Parameters
Coal Mine Methane sites: typical range varies — include planned maintenance
System Output
GO — Site Viable for Deployment
1,407 kW
Gross
→
1,379 kW
After Derate
→
-33 kW
Parasitic
→
1,171 kW
Net
Net kW for Mining
1,171 kW
from 600 scfm @ 40% CH₄
Miners Supported
388
Antminer S19 XP (3.0 kW / 140 TH/s)
Gross Hashrate
54.3 PH/s
TH/s
Effective Uptime
88%
7,709 hrs/yr effective
Altitude + Temp Derate Factor
2.0% derate
Alt: 1.5% + Temp: 0.5%
ASIC Sizing Recommendation
Commercial-scale deployment: 388 × S19 XP across 10 containers. Grid-independent behind-meter system. Dual connectivity recommended (Starlink + LTE backup).
Minimum Viable Threshold
Min. flow for viability~0 scfm
Min. net kW to break even~35 kW
Min. methane % for recip engine≥ 25% CH₄
Capex Estimate
Total Capex Est.
$1,104,702
Cost/kWh Equiv.
2.5¢
¢/kWh all-in