Stirling Manufacturers

STM Power Inc.

"STM Power Inc. is a developer of on-site, electricity and cogeneration systems using a proprietary Stirling-cycle (external combustion) engine. The Company refers to its products as PowerUnits which it believes produce electricity and heat more economically than other energy conversion technologies competing in the distributed generation market (fuel cells, microturbines and photovoltaic systems). The Company's first product, a 25 kW PowerUnit, began testing in December 1999. A renewable DG product, the SunDish Solar system, has already been installed in five test facilities.

To date, STM Power have sold its assets to Stirling Biopower, Inc." ... Stirling Biopower

"For nearly a quarter of a century, Infinia has pioneered new ways to meet the world's needs for electricity, heating and cooling. We work in a spirit of partnership with our customers, partners, employees, investors, and the wider community. The site tells you more about who we are, what we are doing and how we do it."... more

The Cyclone Engine

"The Cyclone Engine is a Rankine Cycle heat regenerative external combustion engine, otherwise known as a 'Schoell Cycle' engine. It creates mechanical energy by heating and cooling water in a closed-loop, piston-based engine system. The process looks like this:

HEAT PROCESS
  1 Fuel is atomized and injected into the patented centrifugal combustion chamber (shown as lifted off the engine block for better viewing), where a spark ignites the fuel-air mixture into a flame that spins around the heat coils. Thermocouples (not pictured) control the duration of combustion to keep the heat in the combustion chamber at a constant temperature.
  2 Water contained in the coils becomes super-heated steam (up to 1200°F) in as little as 5 seconds from start up which is (a) piped to the cylinders, (b) where it enters through a patent-pending valve system (not pictured). Note, valve timing mechanisms regulate how much steam enters the cylinders - the longer the cut-off the greater the torque and acceleration.

MECHANICAL PROCESS
Steam enters the six radial-configured cylinders under pressures up to 3200 psi to push the pistons down in sequence. Note, no motor oil is used - water is both the working fluid and engine lubricant. Also, because of the valve design, the engine starts without the need of a starter motor." more

"Stirling Technology, Inc

Stirling Technology, Inc are committed to the development of sustainable, environmentally friendly technologies. Since 1984 Stirling Technology have been designing Stirling cycle engines for field use. In 1989 are developed a patented Rotary Core Heat Exchanger based on the knowledge of high heat transfer requirements of Stirling engines. Stirling Technology have since been working to perfect the products through the use of high grade modern materials, and by simplifying the designs. Unlike the motors in an original units, the RecoupAerators®of today feature an unique single-motor belt driven system, which uses less energy and functions better than our earlier designs and those still used by PV Technologies of Energy Recovery and Heat Recovery Ventilators.

The ST-5 is a multipurpose external-combustion engine designed for those who either cannot obtain grid electricity easily and economically or have realized the uncertainty of total dependence on utilities to supply their power needs. Virtually any combustible material is a suitable fuel for the ST-5. Among various acceptable fuels are wood, wood pellets, husks and chaff, peanut shells, weeds and hay, cotton waste, other agro-byproducts, and natural gas.

Rugged and reliable, the ST-5 has no spark plugs, carburetor or fuel injectors and is much quieter than an internal combustion" ... more

"Cleanergy is unique by having accumulated 20 years of Stirling engine experience with unrivalled independently verified performance credentials.

The gas powered version of Cleanergy's Stirling engine has accumulated over two million operating hours from over 100 sites, making Cleanergy the premiere Stirling engine provider in the world.

Cleanergy
"Cleanergy is the world's leading provider of Stirling based climate friendly energy solutions

Technical concept
Invented as early as 1816, the Stirling engine has been developed and tested in multiple applications including radio transceivers, mining equipment, submarines, and most importantly for stationary power production. The basic principle of the Stirling engine is that by providing cyclic compression and expansion of a working gas at different temperatures a net conversion of heat power can be converted to mechanical and electrical work. In contrast to internal combustion engines, Stirling engines can run on any available heat source, not just one produced by combustion. The engine mechanisms of Stirling engines are also relatively simple and do not include valves to control variable shaft speeds. These basic features of the Stirling engine enable the design of engines with very long service intervals and technical life lengths.

Cleanergy Solar Stirling Unit
Stirling-Dish Systems are small power generation sets which generate electricity by using direct solar radiation. The capacity of a single unit is 10 kW electric power. The modularity of the Cleanergy solar stirling units qualify the Dish-Stirling system for very flexible applications. They are ideal for standalone or other decentralized applications as well as clusters with a capacity of up to several 100 megawatts.

The parabolic concentrator reflects the incoming solar radiation onto a cavity receiver which is located at the concentrator's focal point. The solar radiation is absorbed by the heat exchanger and thus heats the working gas of the Stirling engine to temperatures of about 650°C. This heat is converted into mechanical energy by the Stirling engine. An electrical generator, directly connected to the crankshaft of the engine, converts the mechanical energy into electricity (AC). To constantly keep the reflected radiation at the focal point during the day, a sun-tracking system rotates the solar concentrator continuously around two axes to follow the daily path of the sun. The Stirling cycle is the most efficient thermodynamic cycle to transform heat into mechanical or electrical energy." ... more

"Kockums is at the forefront of maritime and naval technology - above and below the surface. We design, build and maintain submarines and naval surface ships that are tailored for the littoral zone and incorporate the most advanced stealth technology. Other successful products include our Stirling air independent propulsion (AIP) system, mine countermeasures (MCM), submarine rescue systems and advanced composite material technology."

Kockums, a World-leading Submarine Programme
Kockums designs, builds and maintains advanced non-nuclear sub-marines for operations in both extreme littoral zones and blue waters. Leading technology built into these vessel include our innovative Air-Independent Propulsion (AIP) system based on the Stirling engine.

Stirling AIP eliminates surfacing for regular battery charging, and our submarines can therefore remain under water for weeks rather than days. In combination with superior stealth technology, extreme shock resistance and a powerful combat system, the Stirling AIP system makes Kockums product an exceptional non-nuclear submarine... " more

The Stirling engine is a heat engine
In a Stirling engine heat is produced in a combustion chamber separated from the actual engine. The heat is tranferred to the engine's working gas, operating in a completely closed system. The working gas forces the pistons in the engine to move, thus producing mechanical energy. All that the Stirling engine needs is heat and it does not matter how the heat is produced. It can come from sun radiation or from anything that burns: oil, diesel, petrol or gas. In addition, the Stirling engine is flexible, silent and virtually vibration-free. All these characteristics open a wide field of applications.

Stirling and the environment - Ripasso Energy
The practically unlimited choice of fuel makes the Stirling engine extremely flexible. Furthermore, the fact that the Stirling external-combustion engine is one of the cleanest engines in the world makes it a very interesting alternative for the future.

In 2009 Kockums entered into a licence agreement with Ripasso Energy AB regarding concentra-ted solar energy solutions based on Kockums Stirling engine." ... more about Kockums

Ripasso Energy

"Ripasso Energy is a private company, which was founded in 2008. We have access to state of the art stirling technology and work close with partners having excellent professional capabilities in volume production and supply chain management. Ripasso Energy is committed to become a major global player in providing cost efficient and reliable products for electricity generation to challenge the global climate change.

Ripasso Energy develops and delivers highly efficient and reliable energy solutions for electricity generation on the global market. Our Concentrated Solar Power systems are delivered to utility companies and power systems suppliers on the global market.

We use our competence, strengthened through partnership, to create innovative cost-efficient products, services and processes of professional excellence to create substantial values for our customers and investors.

A unique stirling engine knowledge
Kockums, an important partner to Ripasso Energy, has developed stirling engines for almost fifty years. To date it is the only company that continuously and successfully has commercialized stirling engines with power output exceeding 10 kW.

Agreement with Kockums guarantees us the latest technology
Based on Kockums stirling technology, Ripasso Energy has signed a license agreement to develop, market, manufacture and sell energy systems on the global market. That agreement also includes provisions for mutual exchange of technologies emanating from current and future developments." ... more

"Single-Phase Power (SPP) was founded 2006 to supply solutions for profitable energy recycling, through high temperature heat pumps and waste heat powerplants.

Single-Phase Power AS is registred in Røyrvik in the county of Nord-Trøndelag in Norway, where the engines are produced and serviced."

Technology
Single-Phase Power uses a combination of reliable engine technology and results from recent academic research into low temperature heat engines. The result is a cutting-edge solution for heat pumping and power generation.

The high temperature heat pump from Single-Phase Power is based on a single-phase process. The process is independent of working pressures and boiling points. This means that the heat pump works perfectly for all temperatures (up to approximately 200°C / 400°F - higher temperatures are possible by modifying specific components). The whole process is confined inside the heat pump, and the working medium is less than 2 kg of helium, an environmentally friendly, non-toxic and not flammable gas.

The process is based on the stirling cycle, which have been used for producing liquid nitrogen and other cryogenic applications. It was not until 1980 that professor Ivo Kolin at the university in Zagreb demonstrated that the process could be optimised for small temperature differences. The process was gradually better understood and documented, and Single-Phase Power are one of the few companies that have made large scale industrial heat pumps based on the process.
Products
High temperature heat pump
Single-Phase Power's heat pumps can lift heat from any temperatures up to about 200°C (even higher temperatures are possible.)

The energy cost is dependent on the operating hours and the thermal efficiency. The thermal efficency of the engine is strongly dependent on the temperature difference between the heat source and sink, but a Coefficient of Perfomance (COP) of 60% of the theoretical maximum is a good first approximation. For instance the first commercial installation operates with sink and source temperatures of 120°C and 0° respectively, and has a hot side COP of 2 and a thermal power of 400 kW heat (200 kW cooling) with higher COP at off-design.

Power from low temperature heat sources
The engines used for generating power from low temperture heat sources are similar to the heat pumps and have the same requirements with resepect to installations. The installations comes with advanced power electronics to ensure that the power that is fed to the grid is of high quality.

The engines have been tested on temperature differences of down to 40°C, but for the installation to be economically feasible temperature differences should be at least 70°C. " ... more

Stirling DK

In contrast to traditional internal combustion engines, requiring refined fuels such as oil or gas to operate, a Stirling engine runs on heat from an external source e.g. an external combustion of biomass. In principle, Stirling DK's engines can generate electricity from any high-temperature source. Possible fuel types include e.g. wood chips, biological oil and fat, biogas, and a range of other fuels.

Stirling DK's technology is state-of-the-art and the Stirling engine technology is considered the most promising technology for the production of power from biomass in small-scale applications.

Customers for this technology include district heating plants, municipalities, industries with need for process heat, and in principle any residential owner/real estate administrator of large buildings such as schools, nurseries, apartment complexes, hospitals, office buildings, etc.

In addition, the technology can substitute diesel generators in remote regions all over the world which are not connected to the electrical grid. The technology provides customers with the possibility to use locally sourced, carbon-neutral fuel resources instead of relying on imported fossil fuels." ... more

Sunpower Inc.
"Sunpower is the world leader in free-piston Stirling technology. Our reputation for producing reliable and efficient Stirling engines and cryocoolers is known world-wide.

Sunpower's engineering services include prototype design, development and fabrication of free-piston Stirling engines. The CryoTel line of cryocoolers has outstanding performance, manufacturing accuracy, and quality.

Since the invention of the free-piston Stirling engine in the early 1960’s, Sunpower’s extensive research and development has been applied to the following Sunpower core technologies:
  - Stirling engines that produce power from any heat source
  - Stirling cryocoolers that use power to move heat

Sunpower Engines
Sunpower is a recognized world leader in state-of-the-art, highly efficient, low mass, reliable Stirling machines. Since 1974, Sunpower, the originator of the free-piston Stirling engine (FPSE), has developed and delivered fully engineered engine prototypes and preproduction units for a variety of fields of use in aerospace, military, household appliance and research industries at power levels ranging from 35 We to 7.5 kWe

Sunpower Cryocoolers
CryoTel® cryocoolers, Sunpower's Stirling cryocoolers, are the result of over thirty years of technical leadership, innovation and evolution in free-piston Stirling technology.

With Sunpower's reputation for quality and performance, the CryoTel® family of cryocoolers is increasingly used in the medical, instrumentation, security, astronomy, telecommunications, and pharmaceuticals markets. Sunpower's cryocoolers integrate with and support technologies such as high temperature superconductivity, radiation detection, optics, CCD, LNA, gas liquefaction, and more...

Sunpower linear alternator
Sunpower's linear alternator is a unique device designed by Sunpower specifically for our free-piston technology. It is a key component that converts the linear motion of the engine's piston to electricity, or vice versa." ... more

Sunvention GmbH
"Sunvention GmbH has been developing efficient solar systems for decades. The systems are intended for rural self-sufficiency applications in sun-rich countries. The first systems are now ready to enter production. Due to their simple construction they can be produced locally, creating local employment as a foundation of a healthy regional economy.

The following machines will enter series production during 2011/2012 for delivery as a construction kit to workshops which will perform final assembly for the end-user: the Energy Power Greenhouse (EPG), the SunPulse Water solar thermal water pump, the SunPulse Electric solar thermal electrical generator and the CleanPhoton solar drinking water disinfection system.

Future product development: a solar thermal storage system, a solar cooker, a solar 'stand-alone' system (see fact sheet SunPulse Electric), a solar dryer, a solar cooling system, a fixed-focus solar concentrator and a compact multiple-application low-temperature Stirling engine (the Y-Machine).

The Y-Machine
Sunvention's SunPulse engines have proven that it is possible to efficiently transform solar radiation to mechanical and electrical energy at relatively low temperatures and small temperature differences. It has become possible to produce efficient machines with relatively simple technology.

So that these machines can be constructed in simple workshops and in the so-called Third World, normal air at atmospheric pressure was chosen as a working fluid. The resulting engines are relatively large, and run at low rotational frequency.

To achieve higher output power in the range of several 10s of kW, it is necessary to make the engine smaller. This means either increasing the pressure of the working fluid (air) and/or increasing the rotational frequency of the engine. The Y-Machine represents such a development of the SunPulse engine. A working pressure of 200 bar was chosen, which implies a 200-fold size reduction over the SunPulse engine at the same rotational frequency. The rotational frequency was deliberately kept low to achieve a very long engine lifetime and good thermodynamic transfer efficiency.

To do so, it was necessary to develop a novel heat exchange system for both the hot and cold sides, capable of effective heat transfer at temperatures below 100 degrees Celsius. This is very elegantly achieved through a combination of a liquid displacer piston and the use of a few quirks of physics." ... more

Microgen Engine Corporation
"Microgen Engine Corporation is developing and supplying Stirling Engines for the next generation in home heating systems and a range of applications.

We live in a changing world with governments and consumers seeking solutions to the challenges of climate change and increasing concerns over the security and cost of energy supplies. Microgen Engine Corporation is developing one solution that can help us address these challenges.

MEC is working with leading appliance manufacturers to integrate its unique Free-Piston Stirling generator technology into a range of innovative microCHP products. Together with major energy suppliers in target markets, these companies will collaborate to bring the benefits of Microgen technology to homes, small businesses and public buildings.

Microgen microCHP
The Microgen powered portfolio of domestic heating appliances are wall mounted high efficiency condensing boilers incorporating a MEC designed Stirling Engine Generator. With all the same features, benefits and functionality of modern condensing boilers but with the added value of electricity production they make an attractive alternative to traditional wall mounted or floor standing units.

They belong to the commonly used term of Micro Combined Heat and Power Appliance (microCHP)." ... more

Nye Thermodynamics Corp

"Nye Thermodynamics Corporation arose from our early turbocharger turbine development days. Way back in 1984 we realized that the jet engine from a turbocharger concept was viable as a prime mover for many applications. NTC really got rolling commercially back in 1996 when our first web page connected us with thousands of like minded and encouraging people. NTC has evolved and matured into a provider of custom turbine components and consulting. NTC continues to develop its reputation for being innovative and will continue to network and accrue various turbine related skills and technologies.

Most recently NTC has been focusing on it's Bio-Fueled Microturbine generator for distributed generation of combined heat and power.

NT6 Wood Burning Turbine, the worlds' first wood burning generator / Turbine wood-stove

NT/6 Highlights (proposed specifications)
  - self starting.
  - runs on wood, garbage or bio-mass (or anything else you can stuff into the combustor that burns and gives off good heat).
  - totally self sufficient - can be run in remote locations without gas or diesel fuel.
  - expected to produce around 2,000W continuous.
  - DC output: 24V @ 80A
  - AC output: 120 - 240V at 50-60Hz (AC output will depend upon battery and inverter capacity)
  - excellent source of warmth.
  - fuel wood consumption: TBA.
  - easy to maintain, (change the oil every few months)
  - reliable, turbos are simple and last a long time." ... more

Whisper Tech Limited
"Innovation, environmental responsibility, and uncompromising high quality are the standards that drive Whisper Tech Limited. We are committed to the design, development and implementation of our innovative on-grid and off-grid heat and power systems for international distribution.

Whisper Tech Limited was formed in 1995 and currently has its head office, along with its research and development and some manufacturing facilities, based in Christchurch, New Zealand.

Technology
The core innovative technology behind the success of the WhisperGen heat and power system is a Stirling external combustion engine.

The four cylinder Stirling WhisperGen^TM heat and power system, first released commercially in 1998, produces electricity and hot water suitable for household use or space heating. A patented mechanism, the Wobble Yoke, transfers the vertical motion of the pistons to the rotary motion of the alternator.

The heat to the engine is provided by a burner. Various burners, developed by Whisper Tech Limited specifically for the WhisperGen^TM heat and power system, allow different models to operate on specific fuels including diesel, kerosene and natural gas.

Products
We have offered two innovative products that share the same core Stirling technology; one an on-grid heat-demand led WhisperGen microCHP system designed for domestic home use and the other an electricity-demand led off-grid WhisperGen^TM heat and power system that is ideal for marine and/or small off-grid/remote dwellings and applications." ... more