Uses of the ST-5

The ST-5 has been designed for long periods of stationary use for residential and small-scale agricultural and industrial purposes. Any application which requires a long life prime mover and continuous hours of operation is a good candidate for the ST-5. Recommended uses are electricity generation, water-pumping and powering of small scale implements, compressors, etc.

The ST-5 is ideal for powering a rotary electric generator producing up to 3.5 kW o felectricity, either AC or DC. The engine has been designed so that it can operate at full output for extended periods of time. This is why the ST-5, despite being only a 5-plus hp prime mover, is sufficient for a 3 kW generator which would use a 7 or 8 horsepower IC engine to power it. The engine's speed is governed to operate at 650 RPM so that the electric frequency can be maintained at 60 hertz, but slight variations are inevitable. A voltage regulator would be required for appliances such as television sets and computers. Incorporating the ST-5 into a gen-set configuration requires a radiator, an engine-driven radiator fan and a suitable generator matched to the engine with pulleys, belts or gears to provide for required frequency output. Examples of the appliances which can be operated with 3kW of electricity, along with the constant and surge (starting) loads for each are shown below.

Note: These are averages. Check your equipment for exact wattage. The starting loads on some equipment may be considerably higher. Check your equipment for individual starting loads.

For water pumping, the ST-5 requires only a suitable centrifugal water pump, as the cooling for the engine is supplied by the water being pumped. The amount of water pumped will depend on the efficiency of the pump and on the depth from which the water is pumped. The graph below assumes that the water pump is 60% efficient; i.e. 60% of the 5 hp put out by the engine is converted into pumped water.

Compressors, small machines such as shredders, log splitters and grinders, like the generator, require the addition of a radiator and fan, and pulleys or gears to match the engine speed to the load. Among applications currently being examined are oil jacks for wells less than 3,000 feet in depth where the ST-5 runs directly off the impure natural gas or crude oil found at well sites, a small scale rice milling system using part of the waste husk as fuel and small scale milk condensing plants, utilizing the heat from the engine as well as the mechanical power.

Useable Heat - A Stirling Phenomenon
The burner of the ST-5 behaves like a high quality biomass-burning stove. As a result, a tremendous amount of clean heat is available for use. In addition to the burner heat which is easily recovered, the cooling water of the engine also provides useable heat.

By the use of simple heat exchangers, this heat can be used for space heating of your house, dairy or greenhouse as well as supplying your domestic hot water needs. At full output, the engine produces over 25kW of recoverable heat - far in excess of the needs of an average house.

The ST-5 makes cogeneration - recovering this heat for space and domestic water heating while simultaneously generating electricity - practical.