Friday, April 22, 2016

System Modeling Software for Isotherm's Hydrogen Energy Storage Architecture

Isotherm Energy is developing a suite of software tools to simulate, analyze and design systems based on its hydrogen energy storage architecture.  The software allows selection of various input energy sources, water sources, biomass and other inputs as shown in the screen shot below.

Subsequent screens allow the selection of options for hydrogen production, storage, byproducts, power generation, heat recovery, power output, excess hydrogen, and water management.  Once the architecture options are selected, the software generates a system model that incorporates all the chosen parameters.

Below is an example of one of these system models that incorporates wind, photovoltaics, saltwater, electrolytic hydrogen production, compressed gas storage, fuel cells, and potable water production.  Oxygen is also stored as a cryogenic liquid in this model permitting passive cooling of the compressed hydrogen for greater density storage and higher fuel cell efficiency.

The system model calculates all energy and mass flows between subsystems along with heat available for recovery and improved overall system performance.  Note that all system flows are driven by the load following function of the power management and distribution (PMAD) subsystem and calculated accordingly.

The above screenshot represents a daylight scenario where the combined wind and solar energy input is sufficient to meet the electrical load, so the excess energy is directed by the PMAD subsystem to the saltwater electrolyzer.  Hydrogen and oxygen are thereby produced to be stored for later use in the fuel cell when needed.  Commercially saleable chlorine and sodium hydroxide byproducts are also produced during the saltwater electrolysis process.

When solar energy is unavailable, the system must augment the wind power by consuming stored hydrogen along with ambient air (or oxygen in this case) in the fuel cell to meet the electrical load demand.  The screenshot below shows the system model in this night time scenario.  With appropriate material selection and design, potable water is produced when the fuel cell is operating (for drinking water, irrigation, humidity control, etc.).

The system model has an optional time stamp capability for the conditions being simulated.  When the “Save Conditions” button is clicked, all of the parameters associated with the time stamped simulation are stored for subsequent transient analysis.  In this manner, a sequence of simulated hours, days, weeks or a full year can be automatically generated and investigated.  Every parameter of the system can then be adjusted using built-in optimization tools to meet the performance goals over any timeframe of interest.

The software also provides complete flexibility in the selection of system variables such as electrical load and energy inputs.  These can be a constant number at a given timestamp, a statistical distribution over a time averaged period, a stochastic probabilistic algorithm (e.g. Monte Carlo), or some other user defined method.

New capabilities under development include: 

  • Detailed subsystem and component model
  • Drop-in capability for existing and emerging technologies
  • Comparison to other storage options (e.g. batteries, compressed air, pumped hydro, etc.)
  • Capital/operating expenditures, payback period, levelized cost of energy and other financials
  • Detailed design data, product selections, bill of materials, and more...

Isotherm Energy is developing this software to customize its hydrogen energy storage architecture for a wide range of applications in collaboration with its partners and clients.  Planned case studies will begin to explore grid connected and off-grid scenarios, particularly in markets where the benefits of the architecture uniquely address inherent key requirements and constraints (e.g. controlled environment agriculture).  Please contact us if your organization has interest in participating in these early stage studies.

Matt Moran is the Managing Member at Moran Innovation, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems since 1982. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been involved in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations.  More about Matt here