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DG Update:News & views on distributed generation

Issue 4 and Volume 104.

SOFC Reaches Milestone

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Siemens Westinghouse Power Corp.’s 100 kW solid oxide fuel cell (SOFC) power system, the world’s largest, has completed one year of total operating time, a record for a fuel cell of this type and size. The milestone is the halfway point in a two-year demonstration program.

The system is installed at a cogeneration plant in Westervoort, the Netherlands. It is one of several cells being developed by Siemens Westinghouse under a jointly funded $196 million program with the National Energy Technology Laboratory, part of the DOE Office of Fossil Energy.

The test unit has operated for almost 9,000 hours, supplying 110 kW to the local grid, plus hot water for the area’s district heating system. The unit’s fuel-to-electricity efficiency has been 46 percent to date.

The company plans to begin commercial production of solid oxide fuel cells in the 250 kW to 1,000 kW range in 2004.

The Dutch demonstration will be followed by more tests at different scales and in different market applications. A 250 kW fuel cell and gas turbine hybrid system in California was slated to enter service this spring. Ontario Hydro will be the next North American host for a 250 kW demonstration system later this year. All the demonstrations use natural gas.

IEEE Announces PV Connection Standards

An IEEE-sponsored working group has developed an interconnection standard that will simplify the process of interconnecting photovoltaic systems (PV) with an electric utility. This standard is the first IEEE standard of its kind for allowing utility interconnections of non-utility-owned distributed generation equipment. The unique aspects of this standard include tightly-defined requirements for the interconnecting hardware that can be tested by an independent test laboratory such as Underwriters Laboratories, which is expected to remove former barriers to PV use throughout the country.

It required a little over three years from initial announcement of the project to final approval by the IEEE Standards Board. PV interconnection hardware can now be designed to meet the standard, eliminating the need for specialized hardware for different utility jurisdictions. The standard includes very specific requirements for systems of up to 10 kW, but it covers systems of all sizes. The IEEE PV interconnection standard, identified as IEEE Std 929-2000, is known informally as IEEE 929.

The standard actually applies to the PV inverter, the device that converts the PV dc energy into utility-compatible ac energy. Similar inverters are used in other distributed generation systems such as fuel cells and microturbines. Many of the requirements for interconnection that are described in IEEE 929 might also be adopted for these other technologies.

IEEE 929 provides guidance for operating voltage and frequency windows, trip times for excursions outside these windows, requirements for waveform distortion, as well as defining a non-islanding inverter. A parallel effort was performed at Underwriters Laboratories.

Briefly Noted

Acetex Energy subsidiary Mingo Junction Energy Center LLC has purchased the blast furnace, gas-fired cogeneraton plant supplying steam and power to the Wheeling-Pittsburgh Steel Corp. plant in Mingo Junction, Ohio. The $60 million facility was previously owned and operated by Air Liquide America Corp. The facility produces 500,000 pounds of steam per hour and up to 35 MW of electricity for the steel plant’s use.

KeySpan Technologies Inc. has agreed to purchase 30 fuel cells from GE MicroGen. The residential, natural gas-powered fuel cells are manufactured by Plug Power and will be tested in New York City and Long Island.

Ballard Power Systems recently unveiled a next-generation fuel cell stack, the Mark 900, which generates 75 kW of power. It is half the size of Ballard’s previous cell and weighs one-third less. The Mark 900 uses UCAR Graph-Tech’s flexible graphite materials and is designed for automotive use. Ballard has also joined forces with Coleman Powermate Inc. to develop co-branded portable and standby power products using Ballard fuel cells.

Concurrent Technologies Corp. (CTC) is collaborating with the U.S. Army Engineer Research and Development Center Corps of Engineers Construction Engineering Research Laboratory to provide testing and evaluation of fuel cell systems for military and commercial applications. CTC will test fuel cell systems ranging in size from 1 kW to 300 kW.

Modesto Energy Limited Partnership is closing its 14 MW waste tire-to-energy facility in Westley, Calif. It has disposed of more than 66 million scrap tires since it entered operation in 1987.

Aggreko has opened a new facility in Sarnia, Ontario, Canada to provide equipment, engineering consultation and planning services.

Vericor Power Systems has opened new corporate headquarters in Alpharetta, Ga.

Thermal Loop System Heats Downtown

Conectiv is building a thermal loop heating and cooling facility for the New Castle County Courthouse in Wilmington, Del. The Courthouse is the first customer to sign on to the system. Conectiv Thermal Systems is building the system to handle additional large customers in the area.

The development of the $15 million Wilmington District Thermal Energy Center can provide strong incentive for other businesses considering locating in Wilmington, according to Tom Shaw, Conectiv executive vice president for energy. Governor Thomas R. Carper expects the system to help revitalize the southern end of the city’s central business district.

“The key to development of a thermal loop is the customers requiring new and upgraded facilities and our ability to provide thermal energy at a cost less than a customer can do it themselves,” Shaw said.

District heating, with a central plant serving many nearby buildings, has been available for 100 years, but district cooling has only been available for the last 10 years.

“There is a good fit between this technology and the need for efficient and economical heating and cooling systems for mid-sized buildings,” said Frank E. DiCola, Conectiv Thermal Systems vice president and general manager. “People are always favorable to ideas that will help them cut costs. It goes down to the economics.” He estimates that customers who already have heating and cooling equipment can save 5 to 10 percent with district heating and cooling, but customers building new facilities can save up to 30 percent.

Construction is under way, with completion expected by April 2001. The existing heating and cooling equipment at Conectiv Corporate headquarters on King Street will be replaced with new hot and chilled water equipment. A 10-inch hot water line will provide 200 F water to heat the 12-story courthouse while a 24-inch line will carry 39 F water to the courthouse’s air conditioners. The Conectiv building will also be heated and cooled by the new system.

“The courthouse will use about 30 to 35 percent of the capacity we can build at King Street,” DiCola said. “If we ever sold out our capacity at King Street, we could build a second facility in the area and integrate the King Street facility with the new facility.” The system was originally designed for expansion and integration in the future.

Water chillers will be housed in the basement of the Conectiv building, which had been a parking garage, and heaters will be sited in the penthouse.

DWSD Installs Generators

The City of Detroit Water & Sewage Department (DWSD) has installed 44 diesel generators to supply its service area health and safety protection in the event of a power outage.

“The loss of our ability to treat and distribute potable water because of a power outage could have grave effects on the system,” said Kathleen Leavy, deputy director. “As for water, an interruption in pumping would create air pockets in the pipes that could permit pipeline contamination from groundwater. Sewage could back up into basements and surface waters. The consequences to the environment, our health and the machinery in our plants could be devastating.”

DWSD operates a water system serving 126 communities and covering 1,000 square miles with a pumping capacity of 1.5 billion gallons per day. The utility operates five water treatment plants and 22 water pumping stations and maintains 3,650 miles of water mains. The sewage system serves 78 communities, spans 858 square miles and pumps 1.2 billion gallons of sewage daily. The utility maintains 14 sewage pumping stations and 3,500 miles of sewer lines.

DWSD will run the 2 MW generators approximately 500 hours annually. “In the end this helps the department’s bottom line and our customers,” said K.V. Ramachandran, DWSD head engineer. “This will go a long way toward offsetting the cost of implementation.”

A-55, Wartsila Testing Fuels

A-55 Inc., the Reno-based developer of A-55 Clean Fuels, and Helsinki-based Wartsila NSD Corp., a medium- and low-speed diesel engine manufacturer, have announced a development agreement aimed at providing low-cost, clean electric power globally.

The program calls for a 12-month development of A-55 fuels in medium-speed Wartsila engines to focus on using less expensive heavy oils as the petroleum base for the fuel, and combusting it under a variety of conditions to determine its compatibility, performance and emissions in diesel engines.

A-55 fuels are emulsions of 20-to-30 percent water and 70-to-80 percent petroleum, bound together by a proprietary additive. The fuel, which has been burned in boilers and combustion turbines, reduces NOx and PM emissions.

Mariah Using Capstone Turbines in CHP Package

Mariah Energy Corp. of Alberta, Canada, has announced a marketing agreement to incorporate Capstone MicroTurbine power systems into its combined heat and power (CHP) systems. Mariah’s CHP systems will combine heat exchangers, load management equipment and electronic controls with Capstone’s low-emission microturbines to produce heat and electricity. The integrated systems will achieve 70 percent to 80 percent thermal efficiency, according to Mariah’s figures.

One of the first installations for the CHP system will be in a combined commercial and residential building in Calgary.

“Developers and building managers tend not to be interested in technology,” said Paul Liddy, Mariah Energy president. “They are interested in cost control and the payback on capital investment instead. They find the promise of reliable back-up power for a building complex and guaranteed competitive rates for heat and power with little or no initial capital outlay really attractive.”