How to Start a Biogas Power Plant for Dairy Farms: Complete Guide

A biogas power plant for dairy farms uses anaerobic digesters to convert cattle dung into biogas and nutrient‑rich slurry. The generated gas may be utilised for electricity generation after purification through a gas‑scrubbing system. Project costs in India vary depending on plant capacity, digester design, electricity generation equipment, civil construction requirements, and site conditions. Certain projects may qualify for government subsidy programmes and formal financing arrangements subject to applicable MNRE guidelines, state‑level procedures, and lender eligibility norms.

What Is a Biogas Power Plant and How Does It Work?

A biogas power plant converts cattle waste into usable energy through a controlled biological process called anaerobic digestion. In this process, microorganisms break down organic matter in the absence of oxygen and release methane-rich gas.

The system generally operates in three stages:

1. Anaerobic Digestion
   Cattle dung and water are mixed and fed into a sealed digester tank. Microbial activity produces raw biogas containing methane, carbon dioxide, moisture, and traces of hydrogen sulphide.
2. Biogas Scrubbing
   The raw gas passes through a biogas scrubber that removes hydrogen sulphide and excess moisture. This stage is important because untreated gas may affect generator efficiency and increase maintenance requirements.
3. Electricity Generation
   The purified gas is supplied to a gas engine or generator set that converts the gas into electricity for approved agricultural or operational use.

A dairy farm with approximately 50 cattle may generate around 10–14 m³ of biogas per day under suitable operating conditions. Actual gas production depends on feedstock quality, moisture content, digester efficiency, ambient temperature, and maintenance practices.

Key Components of a Dairy Farm Biogas System

A dairy-scale biogas digester system includes several interconnected components.

The final project cost depends on plant size, automation level, material quality, and electricity generation capacity.

Step 1 — Feasibility Assessment for Your Dairy Farm

A feasibility assessment helps determine whether a dairy waste energy project is technically and operationally practical.

Feedstock Availability

A minimum herd size of approximately 20 cattle is generally considered suitable for a small biogas digester startup. Average dung production per animal may vary depending on breed, feeding pattern, and farm management practices.

The Total Solids (TS) ratio in the feed mixture is important for stable gas production. Excessively diluted dung may reduce operational efficiency during heavy monsoon periods.

Land Requirement

The digester tank, slurry pit, piping network, and generator shed require dedicated space. Depending on plant scale, approximately 200–500 square feet or more may be required.

Grid Connection or Off-Grid Usage

The intended electricity usage pattern influences plant configuration:

• Off-grid farm operations
• Partial electricity replacement
• Grid-connected systems subject to local approvals

The table below provides indicative operational estimates.

The figures above are indicative estimates and may vary depending on cattle breed, feed composition, moisture content, digester efficiency, and operating practices.

For electricity generation intended to support selected dairy farm operations, larger herd sizes may provide higher and more stable feedstock availability.

Step 2 — Choosing the Right Digester Design

Selecting the correct digester type affects construction cost, maintenance requirements, and gas generation efficiency.

Fixed Dome Digester

The fixed dome model is commonly used for smaller dairy farms because it has:

• Lower construction cost
• No moving metal components
• Underground temperature stability

Several fixed dome categories are recognised under MNRE-supported biogas programs for eligible subsidy consideration.

Floating Drum Digester

The floating drum model uses a movable gas holder that rises and falls depending on gas production volume.

Common features include:

• Visible gas storage indication
• Easier pressure monitoring
• Simplified operational observation

However, floating drum systems may involve higher fabrication and maintenance costs due to the use of metal components.

Continuous Stirred Tank Reactor (CSTR)

Commercial dairy farms with larger cattle populations may evaluate Continuous Stirred Tank Reactor systems.

These systems generally include:

• Mechanical mixing arrangements
• Controlled feedstock flow
• Higher gas consistency
• Larger electricity generation capability

The appropriate biogas digester design depends on:

• Herd size
• Available land
• Budget
• Planned electricity use
• Maintenance capability

Step 3 — Estimating Setup Cost and Getting Subsidies

The capital expenditure for a biogas power plant depends on plant size, generator capacity, digester type, and civil construction requirements.

The table below provides indicative project cost ranges.

Major project cost components are summarised below.

The Ministry of New and Renewable Energy (MNRE) provides Central Financial Assistance (CFA) under approved biogas programs for eligible installations.

For smaller plants, CFA support may range approximately from INR 9,800 to INR 70,400 depending on:

• Plant capacity
• Geographic category
• Beneficiary category
• Applicable scheme guidelines

State Nodal Agencies (SNAs) generally administer subsidy disbursement procedures.

The Ministry of New and Renewable Energy (MNRE) offers Central Financial Assistance (CFA) for eligible biogas installations under the National Bioenergy Programme. CFA availability, quantum, and disbursement depend on plant capacity, beneficiary category, geographic location, and compliance with approved scheme guidelines administered through State Nodal Agencies. Subsidy eligibility, timelines, and approved plant types vary across schemes and state

Step 4 — Regulatory Approvals and Licences Required

A waste to power business involving electricity generation may require multiple approvals depending on project scale and grid connectivity.

The following checklist provides a broad regulatory overview.

The approval sequence may differ across states and project categories.

Before construction begins, project owners should verify:

• Land ownership records
• Electrical compliance requirements
• Waste handling norms
• Grid connection conditions
• Generator installation safety standards

Projects exporting electricity to the grid may require additional technical approvals and metering arrangements.

Here's a more blog-friendly, compliant version with a neutral tone for financing options and a moderately promotional tone for the IIFL Finance section:

Step 5 — Financing Your Biogas Power Plant

Setting up a biogas power plant typically involves multiple cost components, including civil construction, digester installation, gas handling systems, power generation equipment, electrical infrastructure, and ongoing operational requirements. The overall funding requirement may vary depending on plant capacity, feedstock availability, project location, and technology configuration.

As a result, project developers often evaluate a combination of capital contributions, subsidies, and financing solutions to support project implementation.

Funding Sources for Biogas Projects

Depending on eligibility and prevailing government guidelines, project owners may explore:

• Central Financial Assistance (CFA) available under applicable MNRE-supported programmes
• State-level subsidy schemes, where available
• Institutional financing for eligible project costs
• Working capital funding solutions for operational requirements

The availability of subsidies, incentives, and financial support may vary based on project category, location, implementing agency requirements, and applicable regulations.

Business Loans for Biogas Plant Development

Formal financing products such as business loans may be evaluated for funding various project-related expenses, including:

• Civil construction activities
• Biogas digester installation
• Generator and power equipment procurement
• Gas purification and compression systems
• Electrical infrastructure development
• Storage and handling facilities
• Working capital requirements
• Ancillary operational infrastructure

Loan eligibility, sanctioned amount, interest rate, tenure, documentation requirements, and applicable charges are determined by the lender based on internal assessment criteria and borrower-specific factors.

Lenders may review:

• Land ownership or lease-related documentation
• Income and financial records
• Project feasibility and technical reports
• Existing credit obligations
• Cash flow projections
• Repayment capacity

Entrepreneurs and project developers may review business loan solutions from IIFL Finance for eligible business purposes, subject to lender assessment, documentation requirements, and applicable terms and conditions.

IIFL Finance Gold Loan for Short-Term Funding Needs

In addition to traditional business financing, some borrowers may evaluate an IIFL Finance Gold Loan to address short-term funding requirements during project development or operations.

Funds obtained against eligible gold ornaments may be considered for purposes such as:

• Working capital management
• Equipment-related expenses
• Procurement of project materials
• Managing temporary cash flow requirements
• Operational and maintenance expenses

Some features of an IIFL Finance Gold Loan may include:

• Funding against eligible gold ornaments, subject to valuation and applicable norms
• Multiple repayment options, where available
• Simple documentation requirements, as applicable
• Access through branch and digital service channels
• Transparent disclosure of applicable charges and loan terms

The sanctioned amount depends on factors such as the purity, weight, and assessed value of the pledged gold ornaments, applicable Loan-to-Value (LTV) limits, and lender policies at the time of application.

Businesses may also use the IIFL Finance Gold Loan Calculator for indicative planning and repayment estimation.

Borrower Disclosures and Regulatory Considerations

Under applicable RBI regulations governing regulated lending entities, borrowers are generally entitled to receive disclosures relating to:

• Loan-to-Value (LTV) assessment, where applicable
• Interest rate and interest computation methodology
• Processing fees and other applicable charges
• Repayment obligations and schedules
• Foreclosure and prepayment conditions
• Auction-related procedures for secured loans
• Borrower communication and grievance mechanisms

Borrowers should carefully review all loan documentation, disclosures, and product-specific terms before availing any financing facility.

Operational Benefits of a Dairy Farm Biogas Plant

A properly maintained renewable energy farm system may support dairy waste management and controlled energy utilisation for eligible agricultural operations.

Potential operational applications may include:

• Partial replacement of conventional fuel sources
• Controlled use of generated electricity for farm operations
• Organic slurry production for agricultural use
• Reduced unmanaged waste accumulation

The processed slurry generated through anaerobic digestion may be used as organic manure subject to local agricultural practices and handling standards.

The table below provides indicative operational reference values.

Operational performance depends on:

• Feedstock consistency
• Moisture management
• Digester maintenance
• Generator efficiency
• Seasonal conditions
• Plant utilisation practices

Project economics and capital recovery timelines vary significantly across installations and should be independently assessed through technical and financial evaluation before project execution.

Conclusion

Financing a biogas power plant may involve a combination of promoter capital, subsidies, business loans, and other funding solutions depending on project requirements and eligibility criteria. The suitability of any financing option depends on factors such as project size, repayment capacity, operational requirements, and lender assessment.

IIFL Finance offers financing solutions for eligible business and MSME borrowers, including business loans and gold loans, subject to applicable eligibility criteria, documentation requirements, credit assessment, and internal lending policies.

Disclaimer : The information in this blog is for general purposes only and may change without notice. It does not constitute legal, tax, or financial advice. Readers should seek professional guidance and make decisions at their own discretion. IIFL Finance is not liable for any reliance on this content. Read more