Anaerobic Digesters & Biogas Systems Category Guide

What Is Renewable Energy & Methane Capture?

Renewable energy and methane capture systems convert dairy manure into useful energy products—primarily through anaerobic digesters that produce biogas. Biogas can generate electricity, heat, or be upgraded to renewable natural gas. These systems also reduce greenhouse gas emissions for carbon credits.

Why Methane Capture Matters

Dairy manure naturally produces methane, a potent greenhouse gas. Capturing this methane for energy use reduces emissions while creating economic value. With growing climate focus, carbon markets and renewable energy programs create significant revenue opportunities.

Key Benefits

• Energy production: Generate electricity or renewable natural gas
• Carbon credits: Emission reductions have market value
• Odor reduction: Digestion reduces manure odors
• Pathogen reduction: Heat treatment kills many pathogens
• Improved fertilizer: Digestate is more stable and uniform

Technology Options

Anaerobic Digesters

Heated, sealed tanks where bacteria break down manure, producing biogas (methane and carbon dioxide). Various designs suit different farm sizes and manure types.

Covered Lagoons

Less expensive capture systems for warm climates. Lower gas production but simpler technology.

Combined Heat and Power

Generator engines burn biogas to produce electricity and recover waste heat for farm use.

RNG Upgrading

Clean biogas to pipeline-quality renewable natural gas for sale or vehicle fuel.

Economic Considerations

• Capital cost: Digesters require significant investment ($1-5+ million)
• Revenue streams: Energy sales, carbon credits, tipping fees
• Operating costs: Maintenance, labor, monitoring
• Scale requirements: Generally need 1,000+ cows for economic viability
• Third-party development: Developers may finance and operate systems

Is Renewable Energy Right for Your Farm?

Consider methane capture if:

• Herd size exceeds 1,000-1,500 cows
• Energy costs are significant
• Carbon credit markets are accessible
• Odor concerns need addressing
• Third-party developers show interest

Cost Considerations

Complete digester systems cost $1-3 million for mid-size farms, more for larger systems with RNG upgrading. Third-party developers may eliminate capital requirements in exchange for project revenue. Current carbon credit values can make projects attractive that weren't viable previously.