Anaerobic Digestion – Highlights of Successful Project Feasibility Studies


Feasibility studies are a form of decision-making tool that require research, data collection and analysis to evaluate investments in new technology or projects. They answer key questions about a project’s technical and financial viability, including project structure and organization and the costs, benefits, and risks involved. The analyses completed are so important that many grant programs require feasibility studies before making project grant awards. Financial investors and banks commonly may require the most rigorous form of feasibility study prior to making any investment.

What did we do?             

To develop a catalog of steps needed to perform a successful feasibility study, we reviewed the literature on feasibility studies, as well as dozens of studies done on the subject of anaerobic digestion. We also talked with a range of experts in project development.

What have we learned?

General Assessment Study or Screening—Most basic feasibility studies assess the viability of different opportunities within a defined industry or geographic area. On a project level, a general assessment determines if a potential project meets basic criteria thresholds to support more in-depth analysis?

Project-Based, Techno-Economic Study—A higher level of research and analysis is used to establish project viability. These studies consider the costs, benefits, and risks of building a specific type of project, with specific technology, on a specific site. For this purpose the study might incorporate readily available data about technology choices and make assumed adjustments about how it would perform under site-specific conditions. This level of analysis forces project advocates to put their ideas and assumptions on paper and test whether the conclusion is sound and realistic.

Investment-Grade Study—The most rigorous feasibility study is used to validate the marketability of a specific project from an investment perspective. It would look beyond basic techno-economic viability to establish the actual planned inputs and outputs of a project. It can include detailed equipment specifications and estimates, as well as detailed mass, energy, and water balance calculations. It may also identify key providers of feedstocks as well as potential end users. Detailed scheduling may be required to complete financial analyses accurately. With a detailed proforma showing financial analyses of cash flow and return on investment, this high level of feasibility study is sometimes termed “investment-grade.” These types of studies often include sensitivity analyses to explore the impact on a project’s viability from changes to one or more key assumptions. Sensitivity analyses can clarify which of the many assumptions made are most critical to project success.

Getting the best, most reliable and accurate data is perhaps the most critical element of a successful feasibility study. Typical steps observed in many feasibility studies:

  •  Define project goals and scope
  •  Establish the project criteria necessary for success
  •  Inputs: potential feedstocks from measured results, existing data, or surveys of sources
  •  Outputs, calculated from inputs: biogas, liquid and solid effluents and nutrients, and environmental attributes
  •  Financial costs: capital expenses, including cost of money, and ongoing operation and maintenance expenses
  •  Revenues (10 or more): methane energy power or fuel, surplus thermal energy, tip fees, value of solids, liquids-water, liquids-nutrients, environmental attributes, ecosystem services (e.g., GHG offsets, water quality/quantity benefits), carbon dioxide, and/or bioplastics.
  •  Cost offsets as revenues: e.g., rainwater diversion, reduction in manure handling/spreading, odor reduction, avoided disposal, etc.
  •  Financial analyses: cash flow, simple payback, EBITA (earnings before interest, taxes and amortization), net present value, return on investment, sensitivity analyses, life-cycle analyses
  •  Project finance: grants and loan guarantees, debt, and equity
  •  Project ownership and liabilities: including design, build, own, operate, maintain

Future Plans      

We will continue to evaluate methods to add value and publish the full results in a Anaerobic Digestion technology brief on this topic.


Jim Jensen, Sr Bioenergy & Alt Fuel Specialist, Washington State University Energy Program

Craig Frear, Chad Kruger, and Georgine Yorgey, Center for Sustaining Agriculture and Natural Resources, Washington State University

Additional information         


This research was supported by Biomass Research Funds from the WSU Agricultural Research Center; and by the Washington State Department of Commerce.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.