For more information contact:
Dr. Paul Yelvington
Energy Conversion
Technology Leader

Phone: 321-631-3550

Energy Conversion

Worldwide energy consumption is immense and growing. Efficient energy conversion devices (e.g., diesel engines, biomass-to-fuels processes) help minimize losses and preserve natural resources. At Mainstream, we are developing an array of energy conversion solutions that cover the spectrum from a few watts (e.g., fuel cells for unattended sensors) to many kilowatts (e.g., diesel engine generators). These energy conversion devices are pushing the boundaries to ever higher efficiency, power density, and reliability.

Research Areas

In addition to our internally funded research, we perform sponsored research for government and industry clients. Our research sponsors include the Army, Navy, Air Force, Marines, the Defense Advanced Research Projects Agency (DARPA), the Department of Energy (DOE), the Department of Agriculture (USDA), and others.

Our energy conversion R&D is focused in the following three areas:

Diesel and Alternative Fuel Engines AMD-45 Engine

  • Purpose-built diesel engines for demanding, niche applications
  • Custom diesel electronic fuel injection (EFI) hardware and controls
  • Components for small unmanned aerial vehicle (UAV) engines
  • Biogas and other biofuel compatible engines

Thermochemical Biomass Conversion Pyrolysis Reactor

  • Portable fast pyrolysis reactors for conversion of waste biomass
  • Hydrothermal liquefaction of high-moisture feedstocks
  • Stabilization and upgrading of pyrolysis bio-oil
  • Techno-economic analysis of biomass options
  • Research-quantity sales of bio-oil

Portable Power Pyrolysis Reactor

  • Direct methanol fuel cells
  • Micro-combustors for micro-power generation
  • Thermoelectric generators (with Materials Science focus area)
  • Small mobile generators

Our Approach

At Mainstream, we focus on the R&D process rather than any particular "widget" or technology. Our research efforts start with getting a clear understanding of a user's needs and then considering all the available options. We approach each new challenge with a "blank sheet" and without bias toward our own previous inventions.

Engine FEA

We use small, focused design teams to address problems in a tight-knit setting that fosters creativity and effective communication. Computer-aided engineering (CAE) tools and rapid-prototyping are used extensively to speed development timelines.

Unlike most other small companies, Mainstream is engaged in all aspects of providing solutions from initial concept through final manufacturing, sales, and support. We encourage you to see for yourself at our Patents, Manufacturing, and Products pages.

Our Labs and Capabilities


Mainstream has a diverse set of capabilities for the development of energy conversion solutions including:

  • Piston engine design and testing
  • Chemical process design and pilot-scale testing
  • Motor and alternator design and testing
  • Fundamental analysis of fuel chemistry
  • Catalysts synthesis and testing

Control Desk

Mainstream's 85,000-ft² facility in Rockledge, FL includes extensive laboratories and supporting facilities. The facilities used most often for our energy conversion programs are:

  • Large-engine dynamometer test cell (120-hp AC dynamometer)
  • Small-engine dynamometer test cell (30-hp eddy-current dynamometer)
  • Biomass conversion laboratory (1 ton/day pilot-scale fast-pyrolysis reactor)
  • Analytical and wet chemistry laboratories (GC/MS, FTIR, UV-Vis, TGA, DSC, etc.)
  • CNC machine shop (5-axis CNC mill, several 4-axis mills and lathes)