High Performance Free-Piston Stirling EnginesUnrivalled Performance | Energy Efficient | Compact | Robust | Long-Lived

Experience the Benefits of Unique Free-Piston Stirling Technology

Benefits of Patented Sunpower Technology Over Kinematic or OtherFree-Piston DesignsSunpower free-piston Stirling engines are based on patented design features which have evolved into today’s technology and an array of available prototypes.

Sunpower designs are highly differentiated from conventionalkinematic Stirling engines.Also, because Sunpower engines operate on gas bearings, use compact linear alternators and have a simple mechanical configuration, they offer significant benefits over other free-piston designs.

By comparison, kinematic Stirling engines are complicated and expensive to build, and require a lubricant, seals and mechanical bearings which combine to restrict performance and limit life. Also, power output is difficult to change in the kinematic design.Sunpower’s unique combination of gas bearings, compliance and compact linear alternator delivers the highest efficiency,lowest mass free-piston Stirling engines available.Sunpower free-piston Stirling engine technology is protected by more than 30 United States patents and 80 international patents.

Product Development SupportSunpower’s free-piston Stirling engine manufacturing organization is supported by a vibrant R&D group who work closely with customers to develop new solutions or engineer SunpowerÕs engines into new products. Sunpower also maintains a healthy intellectual property/licensing businesswhich can offer customers unique and exclusive positions to our intellectual property.

Sunpower’s free-piston technology is being applied in areas such as cryocoolers and linear compressors, power generationand household refrigeration. Some applications include theworld’s most efficient refrigerator on sale internationally; naturalgas-fueled household cogeneration systems scheduled to enter the market in 2007; and nuclear space power systems.

The commercialization of innovative new technologies enabling unique products requires partnerships and collabora-tion. For any new product, Sunpower’s engineering team is available to work directly with partners at all stages, from proof-of-concept demonstration to design for manufacturer and manufacturing start-up.

EE-35 42We 2.7 32% Electric Heater Air/Water Cooling No 1.4 kg 52 x 157

EE-35-H 42We 2.7 32% Propane/JP-8 Air/Water Cooling Yes 0.6 kg 50 x 142Burner

EE-80 95We 3.0 36% Electric Heater/ Air/Water Cooling No 3.7 kg 69 x 193Propane Burner

EE-80-H(*) 95We 3.0 36% TBD Air/Water Cooling Yes 1.0 kg 65 x 186

EG-1000 1000We 2.7 32% Propane Burner Water Cooling No 35 kg 270 x 435

Source: SY Kim., James Huth, James G.Wood; Performance Characterization of Sunpower Free-Piston Stirling Engines, Sunpower Inc.(*) Projected Values.

Power(nominal) Efficiency

HermeticallySealed Mass

Sunpower Free-Piston Stirling Engine Prototype Availability

PrototypeModel

TemperatureRatio (Th/Tc) Heat Source Heat Rejection

Dimensions,Diameter x Length

in mm (nominal)

For the latest information on Sunpower products, services, corporate news and our online library,

visit our Web site at www.sunpower.com.

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EE-35 engine with pressure vessel removed

Measured Performance, EE-35 and EE-35-H

Measured Performance, EE-80 and EE-80-H

EG-1000 engine with non-recuperative propane burner

Measured Performance, EG-1000

EE-80 engines, opposed pair

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Patented, non-contact gas bearing compliant design

—Compliant displacer floats on gas bearings,allowing non-contact operation

—Eliminates lubrication

—Uses space-efficient planar spring

—Reduces number of critical alignments

—Simplifies manufacturing

—Improves efficiency

—Piston support on gas bearings enables non-contact operation

Highly efficient, low-mass linear alternator with permanent magnet for direct AC output

—Reduced weight through use of efficient copper coil with no end turns and zero mean lamination flux

—Minimal power loss because moving magnets never leave poles

Lightweight, compact size

—Workplace diameter is independent of displacer spring

Unmatched power-to-mass ratio

Configurable to a variety of heat sources depending on application requirements

New designs can be developed and engineered into unique new products

Current commercial, military and aerospace applications use three different prototypes that are available for purchase

Automotive pre-warmer, battery charger Gasoline, diesel

Autonomous consumer and commercial appliances Natural gas, LPG, propane

Electric generation, biomass Wood pellets, unprocessed biomass

Electric generation, distributed, grid connected Natural gas, LPG, propane

Electric generation, off-grid Natural gas, LPG, propane

Electric generation, solar thermal Solar, solar/natural gas hybrid

Fuel-fired battery Butane, propane, methanol, kerosene/diesel

Fuel-fired UPS (uninterruptible power supply) Butane, propane, kerosene/diesel

Heat pump, biomass fueled Wood pellets, unprocessed biomass

Heat pump, residential Natural gas, LPG, propane

Vehicle APU (auxiliary power supply) Gasoline, diesel

Sunpower free-piston Stirling engines now in use or in process offer many product development opportunities in diverse markets using a variety of fuels.

Product Development Potential Fuel Source

Sunpower Advantages Over Conventional Kinematic and Other Free-Piston Designs

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Sunpower Products and Fuel Source Alternatives

For more than 30 years Sunpower, Inc.,

the originator of free-piston Stirling engines, has developed

and delivered fully engineered prototypes and preproduction engines

for a variety of applications in aerospace, military, household

appliance and research industries.

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William Beale invents the free-piston Stirling engine and is awarded U.S. Patent 3,552,120

RE-1000, the first mature free-piston Stirling engine; delivered

Design, development and testing of machines from 35W to 7.5kW,and proven operation on numerous heat sources including solar, gaseous

and liquid fossil fuels, biomass and heat pipes

First demonstration of a tuned dynamic vibration absorber

Demonstration of stand-alone diesel fueled free-piston Stirling engine generator to the US Army, First use of a heat pipe heater head

Demonstration of high-frequency engine operation (115Hz)

Demonstration of balanced opposed configuration engine arrangement

First successful application of on-sun solar powered free-piston Stirling engine (development units run through 1994)

Licensee completes field trial for first free-piston Stirling engine-based household cogeneration appliance

Manufactured cryocooler launched on the 2002 RHESSI mission

Demonstration of and improvement on highest efficiency of small free-piston Stirling engine achieved to date

Demonstration of and improvement on the highest power per unit mass of small free-piston Stirling engine achieved to date

Receipt of NASA funded program to develop next generation Advanced Stirling Convertor (ASC)

Free-piston linear alternator technology available in household refrigerators

Demonstration of dual opposed, low vibration free-piston Stirling engine configuration at Space Technology and Applications International Forum

Free-piston Stirling cooler technology commercially available

Demonstration of 20% efficiency of JP-8 to electric power out in a prototype Wearable Power Supply for the US Department of Defense (DoD)

Milestones in Free-Piston Stirling Engine Development at Sunpower

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'2005 Sunpower Inc. 09/05 OW7743

Working with SunpowerSunpower’s free-piston Stirling engine prototypes, R&D services and intellectual property are sold direct from our corporate development center in Athens, Ohio USA. Evaluation prototypes for selected products are available to qualified customers.For information please contact Sunpower, Inc.

182 Mill Street,Athens, Ohio 45701 USA | P: 740-594-2221 | F: 740-593-7531 | www.sunpower.com | info@sunpower.com

Sunpower products are precision manufactured and tested in a modern production facility adjacent to our research, development and administrative center in Athens, OhioUSA. Manufacturing proximity provides our customers with the highest level of flexibility to meet customization demands.

Sunpower is a world-leading developer of energy efficient, environmentally friendly, free-piston machines for power generation and cooling.These machines include free-pistonStirling engines and cryocoolers, pulse tube cryocoolers, and linear compressors.The company is comprised of manufacturing, contract R&D, and intellectual property licensingdepartments. Sunpower is privately held and is situated in Athens, Ohio USA.

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