Multiple industries produce biogas as part of routine operational process. In most instances, the value potential of this by product is not being realised. The gas can be used for a multitude of applications that can all add value in the right circumstance.
Recently Bluefield performed a feasibility study for a client to assess if the gas produced could be used for onsite power generation and grid buffering.
Equivalent Unit Cost (EUC) analysis was completed to determine if an investment in a power generation system utilising the produced biogas could be justified. This also allows an even option comparison.
Multiple system arrangements were investigated with total cost of ownership and the expected power generated used as the criteria to identify feasible options. The initial option selection focused on a low assumed gas production rate of 2000m3 per day.
Analysis included Micro Turbine and Reciprocating Engine systems with both capital purchase and power purchase only options.
Additional hybrid systems were investigated however the high capital cost and site objectives excluded these options and the analysis focused on mechanical generation. In this instance, for an option to be considered feasible it needed to be at a minimum of neutral cost the business over the life of the asset.
The process included a zero base cost build up for a prime power unit using expected capital, operation/ maintenance and project execution and power reduction costs of each option over the defined life of the asset.
The below table identifies the EUC outcome comparison criteria for each of the feasible options.
The below graph identifies the Net Present cash flow and payback periods for each of the feasible options.
The feasible options identify a net present value to the business of $12,000 to $174,000 over nine years with a total payback period of between 3.5 to 8.5 years.
The below table identifies the status of each option analysed, the feasible options are identified in green.