Background
Gas/diesel generators are widely used for mid-to-high power generation for remote railroad wayside applications (control points, interlockings, telecom base stations, etc.) due to their high power, mass market availability and low initial cost. What’s often overlooked is the on-going maintenance needs and associated costs to keep gas/diesel generators operational. You have to change the oil every 25-100 hours, rebuild the engine or even replace the generator entirely after 1,000 to 3,000 hours of service.
Wouldn’t it be nice if there is a power generating solution that could run intermittently or continuously for 60,000+ hours with little to no maintenance? Pioneered in space, Free-Piston Stirling Engines (FPSE) are designed to do just that, providing reliable electrical power supply to the most demanding and mission-critical locations.
How It Works?
Free-Piston Stirling Engine (FPSE) generators can transform virtually any heat source (propane, natural gas, ethane, biogas into electricity. Once heat is applied to the FPSE the heat exchangers maintain a temperature differential across the engine causing the helium to shuttle back-and-forth inside the engine, expanding and contracting. The oscilating helium drives the linear reciprocating motion of the piston, which by means of an integral linear alternator, directly converts the reciprocating motion of the piston into electrical power.
FPSEs have fewer moving parts than traditional kinematic stirling engines, and no direct-contact points that cause wear and require lubrication. FPSEs are truly a maintenance-free technology that offers long-life performance.
Proven Longevity
Free-Piston Stirling Engine have unparalled reliability. Over the past two decades, space agencies have tested multiple engines. Free-Piston Stirling Engines have demonstrated a world record for heat-engines by running in excess of 110,000 hours (more than 12 years) of cumulative undisturbed
operation!
*Qnergy’s PowerGen Free-Piston Stirling Engines are conservatively estimated to provide 60,000 hours of service life.
Rail Applications
- Prime Power (Remote Off-Grid): Suitable as a prime power generator for remote off-grid locations where a standard utility power connection is unavailable and/or too costly. The
PowerGen is capable of cycle charging or running continuously. - Backup Power: Can be used as a backup power system for locations with AC utility power connection. A transfer switch can signal the PowerGen to start and provide power during an AC power outage. Unlike some other power generation technologies (ex: fuel cells), the PowerGen has no start/stop cycle limitations.
- Hybrid Power: Well suited to provide supplemental power to new or existing solar & wind systems. During periods of insufficient solar or wind production (ex: storms, winter months), the PowerGen can be signaled to start and provide charging power. Fueling requirements can be reduced as the PowerGen is only called upon periodically.
PowerGen Advantages
- Variety of Fuel Sources: Can operate seamlessly with a variety of fuel supplies including propane, natural gas, ethane, bio-gas, as well as multiple associated gas streams at
differing caloric values. - ZERO Maintenance: The PowerGen has few moving parts and no direct contact points that cause wear and lubrication (no oil changes).
- Multiple Output Configurations: By means of its flexible and modular design, the PowerGen can be tailored to provide a broad range of power output architectures (standard 120/240 VAC, 24/48VDC optional via PIP Interface) to meet the electrical requirements of
each specific site load. - Long & Simple Operating Life: The PowerGen uses advanced combustion capabilities to quietly and efficiently transform fuel into steady, dependable power from 1.2kW to 5.6kW. Unlike other technologies (ex: fuel cells, generators) there is no reduction in life for multiple start-stops or continuous operation. Design life for the PowerGen is conservatively estimated at 60,000 hours.
Proven Deployment
RedHawk Energy is a leader in the development and deployment of Free-Piston Stirling Engines to the rail signaling and communications market. Since 2017, we’ve deployed several hundred Qnergy’s PowerGen Stirling Engine Generators to rail customers across the United States and Canada looking for reliable backup power.
About US
RedHawk Energy Systems, LLC is a value-added manufacturing subsidiary of the Arthur N. Ulrich Company. Since the early 1980’s, we’ve helped commercial and industrial customers tackle their critical prime and back-up power challenges with innovative solutions ranging from a few watts to several kilowatts. Over the years, RedHawk has been a leader on the deployment of advanced energy systems (solar & wind, fuel cells, thermoelectric generators, stirling engines, and more) for rail wayside power requirements.
Our customers include virtually every Class 1 railroad in North America, shortline railroads, transit agencies, midstream, upstream and downstream oil & gas companies, telecommunication companies, shipping companies, government agencies, Fortune 500 & 1000 corporations, and many others.
Click here to download the Stirling Engine Application Note.