When it comes to summer peak capacity and power reliability, the city of Chicago is trying to beat the heat this summer. The city installed an emergency power system featuring on-site distributed generation equipment.

Now complete, the installation allows the police department's backup emergency generators, each producing nearly 1MW of power, to be remotely dispatched, monitored and controlled. If Chicago experiences power shortages this year, the police department can easily switch from utility-supplied to on-site generated power. The advantages are no downtime, no 911 glitches and no additional costs for expensive peak electricity.

Chicago built its own 10MW power plant, linking scattered backup generators from eight police stations and three senior citizen cooling centers in order to generate enough electricity to power roughly 4,000 homes.

The $400,000 system was inspired by Chicago's failure to keep the lights on in the Loop during the summer of 1999. Encorp, a Windsor, Colo.-based technology company, worked with project contractor Siemens Building Technology Inc. to retrofit six critical emergency backup generators — four at police stations and two at senior citizen cooling centers. The system will help Chicago curtail costly energy demand, said Scott Castelaz, Encorp's vice president of corporate development and external affairs.

Commonwealth Edison (ComEd), Chicago's main supplier of electric energy, spearheaded the effort to contract for negotiable interruptible power, which provides the utility and Chicago with economic savings during times of peak power demand. In addition, generators retrofitted with Encorp equipment can run independent of the ComEd power grid, thus ensuring the police department's critical equipment, such as telephones and computers, are supplied electrical power even during a power outage. The Encorp control equipment enables the Chicago Police Department to monitor and control its on-site power generation system remotely.

Chicago's Preparedness Campaign fueled the decision for future conversion of the police department's natural gas standby generation units to an interconnected grid system.

A goal of the city's recently announced Energy Plan is to provide 1.3 billion kWh of distributed generation to the electrical grid by 2010 — roughly the amount of energy used by 25,000 homes in a year.

Distributed generation is a key component of the Energy Plan, which states: “Chicago is creating the equivalent of a 10MW power plant by amassing the capability of emergency backup generators located at critical city facilities such as police stations and cooling centers. Chicago's energy plan focuses on building virtual power plants through smart energy management, using modern technologies, employing economically meaningful efficiencies and building both a local supply and demand for renewable power.”

After the terrorist attacks of Sept. 11 and concerns about energy security, the city's power plant took on a greater significance. Rather than relying on engineers at each location to switch on the on-site generators, the power plant links all the generators with the flick of a switch from one central spot.

The power plant idea sprang from Chicago Mayor Daley's 2001 Energy Plan — a call to action for how to generate power in the future. The energy blueprint calls for using distributed generation to add 1.5 billion kWh of electricity to the city's power grid by 2010. The energy would be roughly enough to power 25,000 homes. The idea is to link as many independent generators as possible to expand the city's power capabilities.

According to the Chicago Tribune, the concept of distributed power is a major shift in electricity generation. Generally, electricity is dispersed from large plants to homes and businesses. Distributed power makes homes and businesses producers as well as consumers of electricity. Electrons flow on a two-way street. The scheme is called a virtual power plant. Distributed generation can also use newer technologies such as solar cells and wind turbines.


This article originated from Encorp, Windsor, Colo.