Technology Comparison

The SCHMID Group cooperates closely with reliable suppliers on a national and international basis and makes sure that only high quality materials are used to manufacture the EverFlow® energy storage systems.

Comparison with other batteries

Compared to other batteries such as lead-acid batteries,  lithium-ion, sodium-sulfur or sodium-nickel chloride batteries the VRFB shows decisive advantages:

  • Lasting value – electrolyte lifetime of up to 40 years
  • Environmentally friendly: no emissions
  • Non-hazardous because non-flammable and non-explosive
  • Flexible scalability -> performance and energy corresponding to your requirement
  • High cyclical resistance (typically up to 10,000 full cycles)
  • Island capable and mains parallel capability due to integrated inverter
  • No self-discharging in the tanks
  • Integrated real time monitoring and self-diagnosis
  • Low maintenance
  • Compatible with all renewable energy sources
  • Intrinsically safe – design measures ensure highest safety possible.
  • Eco design: repairable
  • Easy to install
  • Real time measuring of charging status
  • Same electrolyte in both tanks: vanadium
  • 100% recyclable
  • Reversible charging and discharging process within the electrolyte
  • 100% deep discharge capability without consequences
  • Developed and manufactured by SCHMID in Freudenstadt, Germany

Off-to-on peak intermittent shifting and firmingCharge at the site of off peak renewable and/or intermittent energy sources; discharge energy into the grid during on speak periods
On-peak intermittent energy smoothing and shapingCharge/discharge seconds to minutes to smooth intermittent generation and/or charge/discharge minutes to hours to shape energy profile
Ancillary service provisionProvide ancillary service capacity in day ahead markets and respond to ISO signaling in real time
Black start provision
Unit sits fully charged, discharging when black start capability is required
Transmission infrastructureUse an energy storage device to defer upgrades in transmission
Distribution infrastructureUse an energy storage device to defer upgrades in distribution
Transportable distribution-level outage mitigationUse a transportable storage unit to provide supplemental power to end users during outages due to short term distribution overload situations
Peak load shifting downstream of distribution system
Charge device during off peak downstream of the distribution system (below secondary transformer); discharge during 2-4 hour daily peak
Intermittent distributed generation integrationCharge/Discharge device to balance local energy use with generation. Sited between the distributed and generation and distribution grid to defer otherwise necessary distribution infrastructure upgrades
End-user time-of-use rate optimization
Charge device when retail TOU prices are low and discharge when prices are high
Uninterruptible power supply
End user deploys energy storage to improve power quality and/or provide back up power during outages
Micro grid formation
Energy storage is deployed in conjunction with local generation to separate from the grid, creating an islanded micro-grid


Definite suitability for application ; Possible use for application ; Unsuitable for application

Source: Grid Energy Storage. U.S. Department of Energy, Dec. 2013