When the electrical power grid was first devised, it was Direct Current or DC based. Supply voltage was limited. So was the distance between the generator and the user. As Alternating Current or AC grids began to be used, electricity could be transmitted over greater distances. Economies of scale in generation increased power output of the generation units. These factors led to the huge transmission and distribution grids and gigantic generation plants we have today.
But today's power grids have aged. Reliability is becoming an issue. The long distance generating plants of today also are an environmental concern. We're seeing need for a less intrusive electrical backup system. This need has drawn our attention back to those early, more localized micro-grids.
When the generating equipment is placed at or near the users' site we call it distributed generation. Distributed generation can provide power to an onsite user or feed a wider distribution grid.
Distributed generation technologies can be gasoline engines, fuel cells and photovoltaic systems. But there's one technology that's been around since the 19th Century that's a natural for distributed generation. It's called the Stirling Engine. The Stirling is an external heat engine that drives an internal piston much like an internal combustion engine does. But the Stirling has no internal combustion. That means heat is applied to the outside of the engine. When the gases inside heat up, they drive the piston.
So? So that means this engine runs on virtually any combustable fuel, not gasoline. You can build a bonfire under the thing and the piston will start moving. When the piston moves, it turns a shaft. When the shaft turns, it drives an electrical generator. The generator produces electrical current for one, or a dozen nearby users.
So? So this engine can use bio-fuels or even geothermal or solar heat to generate electricity. It's moderate cost and fuel versatility makes it perfect for distributed generation. It can provide power for a single family dwelling or an entire village. Unused power even can be fed onto the main power grid to produce additional revenue.
So? So Detroit's having problems with the grid and public lighting. Maybe a few of these Stirling generators salted around the city would provide a dependable backup for local residents. Ultimately, the entire Metro area could have a distributed generation backup system in place. As inclement weather strips through the urban landscape, carrying with it much of the main grid's infrastructure, the secondary system springs to life in minutes.
And you know what? Detroit has a major supplier of these Stirling Engine generators right next door. An outfit called Stirling Biopower is headquartered in Ann Arbor. They've been developing these distributed generation systems for decades. They even offer a solar powered system.
Interested? Here's a link to their site. http://www.stirlingbiopower.com/STIRLING/BASSE.swf
The Stirling Engine is a technology that was invented by a Scotsman, Robert Stirling in 1816. Now, here in the 21st Century, it's becoming a leading edge technology.
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