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The MODE Power System: A Better Biogas Generator Set for Anaerobic Digesters

The MODE (Modular On-Demand Energy) Power System is ready to meet the specific demands of electricity generation from biogas. This new engine-generator set is durable, compact and low-maintenance. The MODE Power System has a proprietary engine, tolerant of hydrogen sulfide (H2S) contamination and is designed for small and mid-sized farms and waste-water treatment plants with anaerobic digesters that wish to generate power for use on-site or sale to the grid. System configurations are available between 16kW and 1 MW+, and installable with heat exchangers for biogas CHP (combined heat and power).

Is Your Farm or Waste-Water Treatment Plant a MODE Power System candidate?

Duryea is currently developing MODE pilot sites. Please read more below about product features and specifications below and contact us if you have additional questions.

MODE Power System Features:
  • Limited moving parts
  • No oil acidification
  • Reduced oil change frequency
  • Liquid-to-liquid heat exchange
  • Top-notch materials and surface treatments for corrosion resistance
  • Integrated compression
  • Highly efficient and durable Duryea (BLDC) brushless generators
  • Ease of grid connection with standard inverter
  • Engine is optimized to decrease emissions and boost fuel efficiency at a fixed low RPM

Durability and Reliability:

Generating electricity from biogas can mitigate the high capital costs of an anaerobic digester. However, when selecting a genset for biogas CHP, farms face a dilemma; invest in a costly gas scrubbing system, or pay increased operations and maintenance costs. Biogas is contaminated with moisture and corrosive hydrogen sulfide, causing increased engine parts wear and necessitating frequent oil changes. Most problems occur when engine oil becomes acidified through contact with combustion gases.

Therefore, the MODE Power System employs a proprietary non-piston engine design, which includes two separate lubrication systems. The oil in the sealed combustion chamber does not migrate to other parts; the combustion process immediately consumes it. Acidification is irrelevant because the limited surfaces in contact with biogas are corrosion resistant. Importantly, the MODE's engine is comprised of less than a tenth of the parts of a conventional piston engine, making parts replacement and overhauls simple and infrequent.

The MODE's robust primary lubrication system has no exposure to combustion gases. It also doubles as a cooling system for superior digester warming via liquid-to-liquid heat exchange. Because there is no combustion contamination, this oil does not get changed outside of major service or overhauls.


Biogas power should be reliable and this is best achieved with a modular system like the MODE. Each compact 2.5’ x 1.5’ unit includes a small, power dense engine and brushless generators, producing 15-18 KW (depending on biogas quality). Duryea packages every MODE Power System unit with a dedicated grid synchronized inverter and integrated compression, further increasing failsafe redundancy.

The MODE Power System is scalable to suit the amount of gas available; the installation is easily expandable by adding additional units until the desired output is achieved - well into the megawatts while maintaining a small footprint. In multiple unit MODE Power Systems, the entirety of biogas electricity production is never off-line; modules are serviced individually while their counterparts continue to generate electricity and keep the digester warm.

Biogas production can fluctuate, and at times the quantity is insufficient for a large conventional piston biogas genset to achieve its nameplate rated output. However, throttling an engine down decreases fuel efficiency and increases emissions as well as the engine’s rate of wear. A multi-unit MODE Power System solves this problem. Individual MODE biogas generator modules are paralleled and synchronized, powering on and off as biogas supply allows. This superior method of operation assures that each small engine module is either operating at its most fuel-efficient RPM or resting and not accruing running hours, maximizing equipment life. The multi-unit system ramps quickly; the engines respond instantaneously to changes in biogas availability.


The MODE Power System comes with Duryea (BLDC) brushless generators and can utilize any standard grid-synchronized inverter, such as commercial three-phase solar string inverters. Interconnection is simplified, and the high-quality output protects on-site electrical equipment.

Duryea BLDC generators are among the most efficient in their class and generate little waste heat, making them extremely durable. Originally developed for hybrid vehicles, they excel at efficient battery charging for off-grid farms.

NO External compressor required:

Integrated compression means a MODE Power System runs lean and fuel-efficient on low-methane and low-pressure biogas. Importantly, no energy-draining external compressor is needed. The necessary compression is achieved with minimal parasitic losses and adjusts electronically to changes in biogas quality, leaving your farm with more electricity to sell to the grid.

Current MODE Power System pilot site candidates are:
  • Farms and WWTPs with anaerobic digesters that need power generation.

  • Farms and WWTPs that have a biogas genset, but still flare excess biogas because their engine has insufficient capacity: Add MODE units to your current system and utilize all available biogas, starting with a minimum excess of 8,000 cubic feet of biogas/day (5.5 SCFM).

  • Farms and WTTPs that cannot export power to the grid or have reached their utility’s KW interconnection limit, but want to reduce kilowatts hours purchased from the utility: Anaerobic digester sites are large consumers of electricity with continuously operational pumps, stirrers and conveyers. Use the MODE to directly power these energy hogs with a VFD and without a grid interconnection.

  • Off-grid farms with anaerobic digesters producing biogas OR with access to propane or natural gas: The MODE Power System, with (BLDC) brushless generators, is ideal for 24/7 reliable power and charging battery banks.

 All product appearance, pricing, availability and technical details are subject to constant change and the information listed on our website may not be current.  Please confirm product specifications with our sales or engineering team before you place your order.

Please contact us if you have additional questions, are interested in an on-site evaluation with a project engineer, or your company would like to install/distribute the MODE Power System.