Energy conservation arguably is the most important aspect to environmental preservation from the perspective of electrical generation. Electricity generation attributes to nearly half of carbon emissions in the US. The process produces more pollution than any other industry in the country. This issue has been getting more attention as of late, and with the mention of it being a matter of national security, you can bet it will shape the engineering of a future economy. To find an answer we must take a trip back in time to consider a process called “Cogeneration.”
The History of Cogeneration
Cogeneration began in the early days of electrical generation when Thomas Edison was the head of the Edison Illumination Company. He had vast resources in those days compared to his competition. Edison, and presumably his very talented team, in 1882 created the world’s first commercial power facility at Pearl Street Station in Manhattan. The facility was used to create a combined utility of heat and power. The facility provided this utility to the local neighborhood with electricity and thermal energy to heat the buildings.
This process also proved to be an effective means to operate industrial facilities. The cogeneration process was easily adapted to the various processes associated with these facilities. The heat energy enabled on-demand thermal heat generation to condition buildings, with the added bonus of a steady heat source to run industrial processes.
The introduction of large steam engines to the industry greatly contributed to the decline of cogeneration uses throughout the 20th Century. However, advancements in modern technology have positioned cogeneration to have its renaissance in the marketplace, showing steady growth in one of the most competitive cities in the world.
How CHP Works
Cogeneration is defined as a process of combined heat and power or (CHP). The process uses a fuel source to thermodynamically capture useful waste heat while simultaneously generating electricity. CHP was refined by the invention of the oil-free and low-maintenance MicroTurbine and high efficiency reciprocating engines. The new twist on CHP systems allows variable speed control over the generation of electricity and thus the production of thermal energy. When demand is low, the system is designed to release excess heat into the atmosphere via condensers or stacks like you’d find at traditional power plants. On the flip side, capturing the majority of this excess heat or flue gas enables CHP plants to run at efficiencies near or above 80%, and when combined with an absorption chiller to provide cooling, efficiencies can rise above 90%. Traditional power plants, such as nuclear facilities, run at efficiencies around 30%. The benefits of recent advancements are astounding.
Current Status of CHP
As with any new technology or method, there is no better test subject than New York City. The construction diversity of the high-rise buildings and overall density of the five boroughs create a need for additional utility resources that can have a negative impact on businesses. Power outages are a problem. Clients are finding that grid connection has its drawbacks. So how do we solve these issues? CHP has become a proven formula to address these issues and strengthen urban-based corporations toward a position of energy independence.
The International Energy Agency launched the International CHP/DHC Collaborative in March 2007 to help evaluate global lessons. A year later they did a study on the viability of CHP in the Big Apple. Their research showed less than 140 small-scale CHP systems were installed, having a total capacity of 118 megawatts of electricity (MWe).
Mayor Bloomberg announced a goal of reducing local greenhouse gas emissions by 30% by 2030. Because of the high efficiency of CHP systems, more widespread use could help reduce emissions associated with power and thermal energy production. During these years, NYC officials established policy with a target of 800 MWe for local CHP deployment by 2030.
Currently New York’s Distributed Energy Resources (DER) generation portfolio consists of 122 MW (57 percent) CHP, 41 percent (89 MW) solar/ PV, and two percent (5 MW) energy storage. Setting a baseline of 118 MW by the CHP/DHC Collaborative compared to the DER data shows New York City to have a 3.3% growth in the CHP industry since 2008.
Cost is an issue to get some projects off the ground. As the cost steadily declines for CHP, more installations go on the books for distributors. To drive down costs, some utility companies offer lease-to-own and other financial packages while other units are sold based on an energy payback period coupled with various incentive packages.
CHP and Resilience
Another advantage of having CHP on-site is to aid critical buildings in the event of a blackout. In 2012, Hurricane Sandy devastated the Northeastern US. One critical site that was hit hard by the storm was a data center on West 17th Street in New York City known as Public Interest. Public Interest has a dual mode MicroTurbine that worked to seamlessly pick up the data center load when the utility power shut down. The servers never went down, and the site has run continuously thanks to the availability of CHP on-demand in the building.
CHP and Cost Savings
As the 2030 target date nears for having 800 MWe of local CHP deployment, and as businesses are ignoring the politics and realizing the need to reduce carbon emissions, the biggest payoff is money. The estimated savings of using less utility-generated electricity is a continued benefit and a wise business decision.