The engineering context
What the assignment needs to resolve
A feasibility study should answer whether a particular site, supply catchment and gas market can support the proposed plant. Starting with a desired tonnes-per-day output and working backwards to a single optimistic feedstock assumption can hide the main investment risk. The study needs a clear distinction between measured facts, supplier statements and assumptions still awaiting confirmation.
The detailed project report connects that evidence to the process basis, project cost, operating model and finance schedule. It should be possible to trace every major revenue or cost line back to a physical quantity, an operating assumption or a documented commercial term. A model that balances mathematically can still be impractical if its feedstock, working capital or delivery assumptions cannot be executed.
What a decision-ready feasibility study must establish
| Workstream | Evidence to examine | Decision it supports |
|---|---|---|
| Feedstock | Supplier locations, seasonality, sample results, competing use and delivered cost | Sustainable plant loading and procurement radius |
| Site and utilities | Usable land, ground levels, access, water and electrical interface | Layout, civil scope and connection costs |
| Gas market | Buyer, delivery point, gas specification and supply schedule | Upgrading, storage, compression and logistics |
| Digestate | Product quality, storage volume, nearby demand and dispatch cost | Handling scope and defensible net realisation |
| Project economics | Package boundaries, operating hours, debt terms and contingency | Base case, downside case and funding requirement |
Altpreneur scope
How we approach the work
Feedstock and catchment
Assess sources, seasonal availability, competing buyers, sample quality, storage losses and delivered cost. Translate the findings into a credible operating feed mix.
Site and infrastructure
Review access, land use, ground levels, drainage, water availability, grid connection, neighbouring receptors and the space needed for storage and vehicle movement.
Process and utilities
Develop the mass-balance basis, gas-production assumptions, digestion concept, purification duty, electricity demand, water balance and digestate handling strategy.
Offtake and finance
Compare gas delivery routes and buyer interfaces. Build CAPEX, OPEX, working-capital and sensitivity cases with an explicit basis for incentives and financing assumptions.
Decisions worth getting right
Test combinations, not one variable at a time
A poor crop year may reduce available feed and increase purchase cost together. The downside case should reflect this relationship instead of assuming all other conditions remain ideal.
Separate project support from cash availability
An announced incentive, an eligibility assessment and an actual sanctioned payment are different stages. Record application, commissioning and disbursement dependencies in the funding schedule.
Keep the conclusion actionable
A useful report ends with a proceed, revise or defer recommendation and the evidence needed to close the remaining gaps. Unresolved conditions should have an owner and a proposed verification step.
Assignment outputs
What you receive
- Site and feedstock findings with a risk register
- Design basis and indicative mass balance
- Equipment and civil scope with budget assumptions
- Financial sensitivities and implementation roadmap
- DPR documentation to the agreed lender or investor format
To begin
Useful starting information
- Proposed location and available land details
- Promoter objectives and indicative investment range
- Any feedstock, buyer or utility information already available
Scope and responsibility
Bank sanction, laboratory fees, geotechnical investigation, statutory charges and detailed engineering are included only when expressly agreed. A feasibility assessment does not guarantee gas yield, subsidy approval or loan sanction.
Common questions
Can we start before choosing plant capacity?
Yes. Capacity should follow a realistic feedstock and offtake assessment. An early study can compare alternatives before selecting the design basis.
Is a DPR the same as a field survey?
No. A field survey establishes site and supply facts. The DPR brings those findings together with process, cost, financing and implementation assumptions.
Evidence & further reading
Source material
- US EPA AgSTAR: Project Development Handbook
- IEA: Sustainable potential and cost of biogas feedstocks
- Cabinet / PIB: Unified GOBARdhan scheme, 6 August 2026
Technical references inform the discussion. Final design, operating limits and policy eligibility depend on the project and applicable current documents.