Every Home Can Use Solar Stirling Engine For Free Energy
The second main category of Stirling engine is a version in which the piston floats freely within a hermetically sealed cylinder thus without an external linkage to drive a generator. This elegant development of the Stirling principle is even more silent than the previous examples and is ideal for domestic use. Sunpower Inc., a US company, plans to introduce a system to the UK in 2007 which is based on a Stirling engine which incorporates an alternator within the cylinder which produces 1 kW of electricity at 50 cycles. This makes it compatible with the grid. The top of the cylinder is heated in the conventional way. The base is cooled by return water from a radiator system which is sufficiently cool to create the pressure difference needed to power the piston. It will be marketed in the UK by Microgen and promises to be an attractive alternative to a conventional domestic boiler (see Fig. 9.10). The UK is a particularly favourable market for this technology for several reasons Figure...
Rather than using electricity to power the compressor and fans, there is the prospect that natural gas or biofuel could be used to heat a Stirling engine to work the compressor and generate electricity for the fans. The excess heat could heat the building or provide domestic hot water. Rather than using electricity to power the compressor and fans, there is the prospect that natural gas or biofuel could be used to heat a Stirling engine to work the compressor and generate electricity for the fans. The excess heat could heat the building or provide domestic hot water.
The alternative system that is already on the market is a micro-CHP (combined heat and power) unit based on the Stirling engine. The UK government is increasingly promoting micro-CHP as part of its strategy to reduce CO2 emissions, especially in the domestic sector. It is interesting how two nineteenth century technologies, the fuel cell and the Stirling engine, are only now coming into their own. Invented by Robert Stirling in 1816, the eponymous machine is an 'external combustion engine' because the heat is applied to the outside of the cylinder. It is a viable technology because of advances in piston technology and The operational principle of the Stirling engine is that a fixed amount of gas is sealed within the chamber of the engine, usually helium, nitrogen or hydrogen. The Stirling engine works on the basis that when heated the gas will expand. Heat is applied to one end of the chamber using a possible variety of fuels to 750-800OC. The increased pressure within the cylinder...
As stated earlier there is already an alpha-type Stirling engine on the market in the UK known as WhisperGen, producing 5 kW as heat and 800 W of electricity. On the verge of being market-ready is a 1 kWe, 15 kWth home CHP package based on a 'free-piston' Stirling engine under the name 'Microgen' (pp. 104 and 106).
The Industrial Revolution introduced water and steam power to power hoists the most primitive form reserved for mine shafts was termed a 'man engine'. This comprised a single pole of connected timbers with platforms at regular intervals (Figure 11.1b). The up and down action was operated by a steam piston engine with the miners having to adroitly jump on and off the fixed platforms at the side of the shaft. Conventional elevators that used passenger cages and guide cables were water powered in those days. Such patterns were in common use until the 1870s and relied upon hydraulic rams to raise and lower the platform, not unlike 'Oildraulic' powered machinery today.
Solar energy offers one of the most abundant sources of electrolysed hydrogen. Deserts flanking the Mediterranean have already been mentioned as the ideal location for parabolic trough or parabolic dish reflectors to produce high-pressure steam to power steam turbines or Stirling engines to create the power to split water. The export of PV and solar hydrogen could transform the economies of some developing countries.
Combined systems that produce both heat and electrical power (combined heat and power, or CHP) are attractive, given the high primary energy value of electricity. Because of their high investment costs they are not interesting for high-performance single family houses because their demand for heat is too small. Where buildings and loads can be aggregated, over a micro heating network to create a greater heating demand, such systems become plausible. Example systems include small natural gas engines or Stirling engines coupled to a heat pump and electrical generator. The fuel cells technology for residential applications, which is now in a pilot phase, is promising.
Solar Stirling Engine Basics Explained
The solar Stirling engine is progressively becoming a viable alternative to solar panels for its higher efficiency. Stirling engines might be the best way to harvest the power provided by the sun. This is an easy-to-understand explanation of how Stirling engines work, the different types, and why they are more efficient than steam engines.