In the wake of extreme weather conditions and accompanying devastation of our built environment, our society has begun taking another look at the way we generate and distribute electricity. It’s a fact that replacing the existing power grid would be an impossible task. However, creating a means to supplement the grid by relieving stress on its infrastructure while simultaneously building resiliency has shown to be a more practical goal. Experts are calling this supplemental design “the Micro Grid.”
Micro Grids are being used as localized electrical distribution systems that combine proven technologies capable of operating with or without grid assistance. Many of these designs incorporate Cogeneration or Combined Heat and Power (CHP) as a central plant.
To understand its benefits, we should acknowledge that CHP is not a new technology. In fact, it’s the oldest form of electrical distribution in recorded history. CHP was created more than a century ago by Thomas Edison and is poised once again to have its day.
Thomas Edison – A Brief History
Thomas Alva Edison was a prolific inventor who lived from 1847 to 1931. He was known by many as “The Wizard of Menlo Park” and would become an American icon in the history of our nation. During his life, Edison had more than one thousand patents in the United Stated and Europe revolutionizing technologies like the phonograph, motion pictures, and eventually electrical generation. He began demonstrating the potential of his electrical experiments in 1879.
Edison wasn’t the first to discover or harness electricity, but he was the first to revolutionize it. By 1879, electricity had already been installed around the world. Having been extensively researched by Benjamin Franklin more than a century before, electrical theory had since been applied in Edison’s time. One experimental installation was the illuminating of electrical arc lamps along the Avenue de l’ Opera in Paris a year earlier, in 1878. These lamps gave off an offensive light that was disturbing to passersby. Edison felt he could change what was already applied and benefit mankind on a more substantial level.
After hundreds of failed attempts, the solution was finally discovered at Edison’s industrialized research lab in Menlo Park, NJ. It was there Edison and his team discovered a carbon filament lightbulb burning in a vacuum that could last longer than other versions of the time and make home lighting more than a dream. It was dubbed the Edison Lamp. This invention got the attention of wealthy businessmen and gained financial backing by the likes of J.P. Morgan and the Vanderbilt family.
The Edison Illuminating Company
Morgan had a vision of the future when seeing the Edison Lamp for the first time. He asked if the inventor’s electrical experiments could be applied on a larger scale. Edison was confident, and in 1880 the two men would establish the Edison Electric Illuminating Company of New York to build the world’s first electrical generating station of its kind.
While designing his first set of Distributed Generation (DG) power stations, Edison’s early clients were wealthy families who could afford this newfangled technology, but with Morgan’s backing, electricity wouldn’t be just a luxury applied to expensive homes for very long.
Edison’s preferred method of electric power transmission was in the form of Direct Current (DC). DC uses a lower voltage and has the best results when distributed over shorter distances. To put things into perspective by today’s terms, DC is commonly found in many extra-low voltage applications and some low-voltage applications. For example most electronic circuits require a DC supply. More especially electronics that are powered by batteries.
DC is easily applied to solar power systems, since solar cells can produce only DC. It’s also used in most automobiles. Although the alternator in a car engine is an AC device, it still uses a rectifier to produce DC. Applications using fuel cells or small Cogeneration plants also produce DC.
The Pearl Street Station
Edison’s first operational station was at 255-257 Pearl Street, Manhattan. It would be the blueprint for his greatest contribution to modern industrialized society. From there, Edison would design and build a small network of districts or grids, each with a central distribution plant. These grids would provide both heat and power to the buildings nearby.
The Con Edison website details the construction of the plant on their History of Electricity page. “At the Pearl Street station in lower Manhattan, Edison’s team installed the largest dynamos ever built. Each dynamo weighed about 27 tons and had an output of 100 kilowatts — enough to power more than 1,100 lights. Each of the six dynamos was driven by a steam engine, which received steam from boilers located in another part of the plant.”
When the station was running at full capacity, the excess steam would be vented through tall stacks. Regardless of his system achieving the desired outcome, there was perfectly good steam going to waste. This factor was a thorn in Edison’s side from the beginning and would eventually lead him to bigger things. The Pearl Street Station was a success per design. It delivered power to surrounding buildings at an affordable rate when compared to natural gas.
Early Micro Grids
The results of Edison’s work became what we know today as Micro Grids. He built central plants that only served small portions of the city. This method was effective because if one grid went down the others would still be operational. As a result of Edison’s success, more plants were built. Soon after, the competition would rise to increase the size of the market and produce his biggest competitor from within his own shop.
Edison was a proponent of DC. His early apprentice and later rival, Nicola Tesla, supported the countering method of Alternating Current (AC). Both are important to modern electrical generation and distribution. However, early on DC was king. DC had its best results when used within closer vicinities, whereas AC could distribute electricity over much longer distances with minimal disruption.
Edison’s vision was to set up small grids across New York. This would supply portions of the city with power. His plan worked, but not without inspiring adversity. Competition had begun rising all over the city in the form of AC distribution. Morgan and Edison would do everything in their power to corner the market – exhibitions displaying the dangers of AC notwithstanding.
Since his first experiments with electricity and the Edison Lamp, his plans for the Pearl Street Station had been an ever evolving theory. Edison’s design to create power generated an exorbitant amount of wasted heat from the coal fueled plants. Edison felt there had to be a use for all this excess energy and his further exploration into the benefits of heat transfer would provide a viable solution to solve this problem. His experiments with converting waste heat to steam eventually led to the DG technology we know today as CHP.
The Pearl Street Station was a CHP plant, and so were all the other plants Edison Illumination Company designed and built. CHP had its day in the early 20th century. These stations ran large process plants while providing heat and power to both the central facility and the neighboring buildings. Its prominence in the market and eventual decline was inevitable. The downfall of CHP can be attributed the rise of the atom.
The Modern Electrical Grid
Nuclear power when combined with AC can create enough energy to power large areas while having enough range for distribution to millions of homes and businesses with minimal disruptions in service. The nuclear power plants were behemoths of epic proportions compared to Edison’s DG plants, each having a lifecycle of 50 years or more. Edison’s DG plants were mothballed and dismantled one by one, leaving only a few scattered about in manufacturing facilities and process plants. The stations that once provided nearly 100% of electrical generation and distribution had fallen to only a minor portion of the market share. As of 2014, CHP plants accounted for a mere 8% of the utilities market.
Weaknesses in our electrical grid were realized during Hurricane Sandy when New York City and much of the greater metropolitan area completely lost grid power for a number of weeks. Following the blackout was the disruption in oil deliveries used to power generators. The loss of our main source of power and its most common back-up has become a hard pill for many to swallow. This problem has created a major dilemma for our society and has since gained the attention of big business and politicians alike.
Current Micro Grid Support
The Offices of Governor Andrew M. Cuomo and Governor Chris Christie have been aggressively pursuing alternative means of affordable electrical generation that would withstand super-storms like Sandy, while maintaining power within much smaller districts: Re-enter the Micro Grid.
Micro Grids in modern time haven’t lost much in the base design of Thomas Edison. Combined heat and power generated using a fuel, in this case natural gas, is a very practical means of providing comfort to those when they need it most.
The programs established by the both Offices look to use CHP as an independent parallel utility, meaning when the main Grid drops out the Micro Grid would still power a large portion of the buildings supplied.
When installing CHP as a central plant then using other DG technologies as ancillary sources of power (solar, wind, battery back-up, electric vehicles, etc.) the results can far outweigh the alternative means, which maintains the status quo. CHP is again proving to be a sound choice in making our energy infrastructure more resilient while providing a first line of defense in the event of extreme weather. It has also become a smart solution to provide utility diversity to infrastructure congested or resource starved areas. Maybe only Thomas Edison himself could have predicted his technology coming full circle more than a century after its conception.