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The following case studies indicate ways DG is being used by energy providers today. Additional case studies may be found within various DG publications and presentations in our DG library, such as the use of fuel cells in an Omaha bank, cogeneration in a semiconductor plant, and interconnection case studies. We have also profiled a number of applications and installations that occurred during 2000-2002 in DG Monitor articles.
Wisconsin Gas is part of the WICOR Energy Group, a $1 billion diversified holding company based in Milwaukee, WI. Wisconsin Energy Corporation (the parent of Wisconsin Electric) and WICOR Inc. are in a merger process.
The combined company will serve approximately 921,000 gas customers and more than one million electric customers in Wisconsin and Michigan's Upper Peninsula. It will operate more than 16,500 miles of gas main and 30,000 miles of electrical transmission and distribution wires. The combined company will have approximately 9,000 employees. After the merger is complete, Wisconsin Gas's backup power program will complement, instead of compete with, Wisconsin Electric's services.
Power Now (PN) is a DG program offered by Wisconsin Gas (WG) with Generac as a partner. They provide Generac natural gas fueled power generators to existing residential and small commercial gas customers. This is a small business program venture - the first new business area explored by Wisconsin Gas to expand its customer outreach. As currently offered, PN is a pilot experiment with only 2 staff members working full-time on the program. The initial program during the second half of 1999 covered eleven counties in Wisconsin, with a residential focus, in an effort to work out the program's bugs and to learn more about the market.
The program was established in response to consumer market research, which indicated that many consumers expect very high reliability. Wisconsin Electric has suffered several severe storms in recent years, with outages, creating a demand for a viable backup power option.
The program offers generators ranging from 5kW to 25kW, ranging in price from $6,495 to $14,995. The purchase price includes site preparation, generator installation, gas piping, installation of all electrical components, generator start-up and testing, a one year warranty and first year preventive maintenance. Security system, pump, heating and refrigeration backup is available with all the packages, with additional well pump, lighting, air conditioning and smaller appliance backup becoming available with the more expensive units. All units require a 10 second engine warm-up, a 1 minute engine cool-down, and provide an auto engine exerciser self-test.
Outreach for PN relies on the internet and existing gas customer mailings. WG is already acquiring commercial customers without marketing to them. When they do expand from the residential market to the commercial market, the focus will be on promoting reliability. Wisconsin Gas will probably offer a 200kW machine for this market segment. Example key niches that they expect to target include: hospital units, assisted living centers, doctor and dentist offices, and grocery stores (note the health care theme). As larger units are necessary in the commercial and light industrial sectors, other DG technologies may be used. For example, microturbines might be marketed to commercial customers the same way PowerNow now distributes reciprocating engines to residential customers.
The main strategy is to sell reliability at an affordable cost from a company with a brand name consumers know and trust.
A key issue is financing. PowerNow works with commercial banks to arrange customer financing. The customer owns the unit even as Generac and Wisconsin Gas provide maintenance and support. This is different than some competitors who believe any consumer out-of-pocket cost is a major deterrent to a DG program; such competitors lease DG equipment to consumers.
ComEd Relies on Distributed Generation for Reliability
Back
to Top of PageSummary of an
article written by Joseph Fiorito
Senior
Purchasing Specialist, ComEd
The summer of 2000 marked the third consecutive year that ComEd (A Unicom Company) used diesel generators for peak shaving, applying distributed generation in the Chicago area.
It began back in 1997, when the effects of El Niño were forecasting increased temperatures throughout the nation. Research began to try and determine what alternatives existed to provide extra power capacity on a temporary basis. After reviewing data from portable diesel generator suppliers, it was determined that is was feasible to supply generation on an as needed basis. With that, a plan was put into place to provide temporary, regional distributed generation to critical areas in the territory. ComEd contracted to rent 90 megawatt’s of portable diesel generation during the months of June through August. Although the running hours were limited, the project was viewed as a success. This success shed light as to the possibilities of providing a quick and cost effective means of local, peak shaving generation.
In 1998, ComEd researched the market for temporary
power alternatives. Areas
that were covered included, power barges, 3-5MW diesels on railcars, and
small jet turbines. Once
again the diesels won out and were contracted for the project.
Only this time, the scope was raised to 210MW’s.
As in the prior year, the performance of the portable units were
put to the test on days where ambient temperatures exceeded 100 °F
and heat indexes above 150. The
units provided substantive power to the tune of 21,420 MWH’s during the
summer months. These needed
MWH’s were especially appreciated when spot market pricing reached
levels in excess of $7000 per MWH.
So where does that put ComEd for the new millenium? This year’s scope has been ramped up to provide 300MW’s of peak shaving, distributed generation. Performance-based contracts have been awarded to the two suppliers from previous years. Patten Power Systems and Aggreko will be challenged once again for the project. These two suppliers have proven themselves over the last two years and will be called upon to deliver the MW’s. Patten Power Systems, the local Caterpillar dealer, will be providing the lion’s share with 160 power modules, producing 240 MW’s at 8 locations. Aggreko’s portion will be supported by 60 power modules generating 60 MW’s at 2 locations.
The Patten Power Systems’ sites typically consist of 20, Caterpillar 1750 kW, utility-grade power modules, each one tied to a single 2500 kVA transformer, then paralleled together into a substation. After extensive planning and coordinating, it will take about a month to set and place the generators, fuel tanks and cabling at all 8 sites. Mechanically, the equipment is installed by dedicated crews utilizing cranes, lift trucks, and tractors. There are over 21 miles of power leads alone. Electrically, the power from each module is delivered through 4, 535 MCM leads per phase. For system protection, each generator is wired with specific safety trips that can be activated both from the substation and the control cabinet within the power module. Examples of those safety measures include reverse power, over-speed, over/under voltage, over/under frequency, and ground/electrical fault.
Similarly, the Aggreko sites include 30, 1250 kW, utility-grade power modules paired to a single 2500 kVA transformer, then paralleled into a substation. Due in part to the unique containerized design of the Aggreko components, they are able to set up a typical site within a week’s time.
As with last year, fuel capacity and consumption shall be a major factor. During a critical operation, fuel was being burned at a rate of 18,000 gallons per hour for more than 15 hours a day. Each site’s generators are paired to a single, external, fuel storage tank. The fuel tanks vary in capacity from 2300 to 2500 gallons, and are certified, double steel wall construction to prevent spillage and leaks. Total site storage capacity was 285,000 gallons. As one might expect, keeping the individual fuel storage tanks filled in the heat of a Chicago summer day, became a monumental task.
ComEd’s contracted fuel supplier Bell Fuels, managed to keeps the trucks running. Their efforts will be challenged once more to keep the units filled. With the increase in scope of the project, the fuel deliveries could reach 70 truckloads a day to keep the generators running. The on site storage this year has been increased to 430,000 gallons to accommodate the additional gensets and anticipated consumption.
Additional lessons learned from the previous years have included derating of the gensets. Given the extreme operating conditions that the generators will be running, each generator will be derated 250 kW. This will give a comfortable operating margin for Aggreko at 25% and Caterpillar with 17%. These margins will yield 1000 kW and 1500 kW for Aggreko and Caterpillar respectfully. At the same time, both Patten Power Systems and Aggreko have incentives built into their contracts to produce additional power at the direction of ComEd.
Where does it go from here? ComEd’s distributed generation project this year is the largest of its kind. With the increased demand for power and physical limitations of existing transmission and distribution systems, distributed generation has the ability to get the power where it’s needed most. The marketplace is emerging, providing many alternatives for localized power production. As deregulation occurs throughout the nation and the call for competitive solutions continues, OEMs and utilities will be pushed to provide answers. The large diesel engine manufacturers have been forthcoming by developing diesel engines with lower sound and exhaust emissions. Combine that with their relative small size per kW and the ease of installation, and the diesel generators have carved their way as the clear, low-cost provider for peak shaving, distributed generation for ComEd.
