Commons Capital


Protonex, Inc.

Protonex, Inc. is a developer of PEM (proton exchange membrane) fuel cell stacks and systems, with unique, proprietary designs and manufacturing methods. The company’s technology increases the useable stack volume, dramatically reduces the stack size and cost, and virtually eliminates the problem of leakage faced by other manufacturers. The company is targeting a variety of low-power portable and remote applications, and has won several government R&D grants.

Location: Marlborough, Massachusetts

Commons Capital's co-investors include:
Conduit Ventures, Massachusetts Green Energy Fund, Parker Hannifin, Solstice Capital, and Silicon Alley Seed Investors


Healthcare Claros Diagnostics
  CodeRyte, Inc.
  Combinent BioMedical Systems
  HistoRx, Inc.
  Medical Metrix Solutions, Inc.
  Teladoc, Inc.
Energy CTP Hydrogen
  H2Gen Innovations
  Pelamis Wave Power Ltd.
  Protonex, Inc.
Education Apex Learning, Inc.
  OutStart Inc.
Environment Niman Ranch
  Passport Systems, Inc.
  Sun & Earth, Inc.
Other Solstice Capital II LP



  | Home | The Fund | Team | Portfolio | Global Health | News | Contact