During the process of researching an article about green products on photovoltaic cell systems (solar panels), I came across another way to convert the sun's light into electricity. So let's take a look at another type of solar energy system.
The Stirling engine was originally invented and patented as an air engine by Robert Stirling in 1816. It may have been designed as a replacement for the steam engine, because the steam engines used in factories would explode frequently, causing many injuries and fatalities. These days, because of the cost of fuel and the environmental problems with coal, many new designs are incorporating the Stirling engine in solar power systems.
The Stirling engine has many different designs, some more efficient than others. Some designs use the two cylinder Alpha design, some the Beta single cylinder design and some the Gamma design (a variation of the beta for use in multiple cylinder applications). The beta Sterling design has a single chamber with two pistons and uses a highly efficient regenerator gas as the thermal conductor.
To operate the Stirling engine only an external heat source is required, which could be anything from solar heat to the heat produced by decaying plants. In one model, the heat from a human hand powers a small version of the Stirling engine!
The Stirling cycle is pretty simple. When a heat source is applied to the large end, it causes the air to expand which moves a piston. A flywheel is used to maintain movement between cycles and add a convenient place to tap the power from the engine. What is so amazing about this design is that the design is very scalable. Engines have been produced that are as small as your hand to a large as a car but the concepts remain the same.
The reason the Stirling engine works so well for a solar application is that heat from the sun can easily be concentrated to heat the hot chamber. A parabolic mirror much like that seen with the roof mounted satellite dishes is used to gather and focus the sunlight. With the sunlight focused onto the hot chamber of the engine, the temperature raises and the engine starts running. Connect the output shaft to a generator, and electricity is the product.
The engine and support equipment is contained in a package small enough to be suspended from the end of a metal arm, much like the design of satellite TV systems but on a much larger scale. Some systems are producing 25K watts of power and have been installed and operational for a couple of years.
I will compare the different solar technologies in a later article. For now, I need to lay a foundational understanding of each of the green products used to produce power so a comparison can be made.
Michael
The Stirling engine was originally invented and patented as an air engine by Robert Stirling in 1816. It may have been designed as a replacement for the steam engine, because the steam engines used in factories would explode frequently, causing many injuries and fatalities. These days, because of the cost of fuel and the environmental problems with coal, many new designs are incorporating the Stirling engine in solar power systems.
The Stirling engine has many different designs, some more efficient than others. Some designs use the two cylinder Alpha design, some the Beta single cylinder design and some the Gamma design (a variation of the beta for use in multiple cylinder applications). The beta Sterling design has a single chamber with two pistons and uses a highly efficient regenerator gas as the thermal conductor.
To operate the Stirling engine only an external heat source is required, which could be anything from solar heat to the heat produced by decaying plants. In one model, the heat from a human hand powers a small version of the Stirling engine!
The Stirling cycle is pretty simple. When a heat source is applied to the large end, it causes the air to expand which moves a piston. A flywheel is used to maintain movement between cycles and add a convenient place to tap the power from the engine. What is so amazing about this design is that the design is very scalable. Engines have been produced that are as small as your hand to a large as a car but the concepts remain the same.
The reason the Stirling engine works so well for a solar application is that heat from the sun can easily be concentrated to heat the hot chamber. A parabolic mirror much like that seen with the roof mounted satellite dishes is used to gather and focus the sunlight. With the sunlight focused onto the hot chamber of the engine, the temperature raises and the engine starts running. Connect the output shaft to a generator, and electricity is the product.
The engine and support equipment is contained in a package small enough to be suspended from the end of a metal arm, much like the design of satellite TV systems but on a much larger scale. Some systems are producing 25K watts of power and have been installed and operational for a couple of years.
I will compare the different solar technologies in a later article. For now, I need to lay a foundational understanding of each of the green products used to produce power so a comparison can be made.
Michael
About the Author:
About the author: Michael Edwards loves to write about green products. See more of his stuff at go green
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