Total Energy Independence

The ST-5 has been 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. If you need electricity at remote locations where grid power is not a feasible proposition; have experienced the inconvenience of grid power failure; wish to avoid the predicted utility "rate shock"; have found the internal combustion engine an undesirable backup for your wind or photovoltaic system; actively seek alternative sources of energy for your security and peace of mind, or if you simply desire an Independent Home Energy System for your home or greenhouse, the ST-5 may be the solution you have been looking for.

The ST-5
The ST-5 is a rugged engine designed to produce over 5 hp of mechanical power reliably and on demand, directly from a variety of renewable and gaseous fuels. Its external combustion Stirling cycle eliminates spark-plugs, fuel-injection systems, mufflers, noxious fumes and, very noticeably, the noise of internal combustion engines. This lack of complexity coupled with the use of high quality sealed bearings and long life Teflon impregnated seals, eliminates the need for messy oil changes and makes possible a long, trouble-free engine life. The ST-5 has been designed to be user serviceable with a minimum of basic hand tools.

Most important of all, 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. This wide variety of suitable fuels ensures that you are able to produce your own fuel on your own land.

The ST-5 System and Operation
The ST-5 system comprises two main components - the ST-5 (engine) and the burner. The function of the burner is to provide heat to the heater head of the ST-5, which is inserted into the burner. Two burner options are now available for the ST-5. One is a cyclone burner for small particle fuels such as sawdust or other shredded biomass. The second is a two stage wood burner. The fuel is fed into the burner either manually, as is the case with the wood burner or through a hopper, if one is using small particle fuel. Gaseous fuels may be used in the cyclone burner by modifying the intake orifice. The wood burner can hold enough fuel to run the engine at full output for two to four hours (depending on the wood used).

 In order to obtain the high temperatures necessary to run the engine, both burners have a forced air blower. Once the engine is started, the blower is operated by the ST-5 itself. Before the engine can be started, however, the blower needs to be operated for 10 minutes either by a battery or by hand cranking until the desired heater head temperature is reached. Once the temperature is high enough (the ST-5 will start at temperatures around 950o F), an easy pull on the flywheel starts the engine. Once up to temperature this engine is an easy and sure start, eliminating the need for multiple pulls on a recoil rope as is often experienced with conventional engines.

Just as the ST-5 takes a few minutes from the time you fire it up until the time you start it, it also takes a while to come to a stop even after the fuel supply has been cut off. This is because the heat retained in the heater head is sufficient for it to operate for 10 to 15 minutes, although at decreasing power output.

The cooling loop works like any automotive cooling system. A small pump, operated by the engine, circulates the cooling liquid (water or water and glycol) through an automotive radiator, while a fan mounted on the flywheel blows air across the radiator and dumps the unused heat into the atmosphere.