GE Microgen and its fuel cell supplier Plug Power (12 per cent owned by GE) expect their residential-size 7 kWe fuel cell power plants to be in commercial operation by late 2001 or 2002, according to Barry Glickman, GE Microgen president.

These initial commercial units would be 60 Hz natural-gas fuelled devices for use in “grid parallel” mode. In the following year, models with improved load-following capacity, ie capable of stand-alone grid-independent operation and able to use propane as fuel would become commercially available, as would 50 Hz units. 2002 would also see introduction of a commercial CHP version, the subject of a recent agreement signed with Vaillant.

Both GE and Plug Power say their relationship is still “intact” following realisation that the pre-commercial units which Plug Power is developing would not conform to every item in a detailed product specification originally agreed on with GE in February 1999. As a result GE was no longer contractually obligated to purchase 485 units on a take or pay basis as set forth in the original agreement.

Test and evaluation is currently underway on some 60 units installed at Plug Power’s facilities and various sites in New York State. These include several supplied to Long Island Power Authority, which has recently reported positive operating experience. Development efforts are currently focusing on improved compactness, improved reliability and better load following capability.

With an expected price tag in the region of $10 000, the GE MIcrogen/Plug Power product – called the HomeGen 7000 – will be initially targeted at niche markets, in particular a seemingly elite group GE calls “electronics consumers”, who own large quantities of computers and other electronics and are prepared to pay a premium for better power quality and reliability.

GE expects it will be 3-7 years before costs get down to “mass market” levels, ie around $500/kW. GE also sees huge potential for distributed power, including fuel cells, in the developing countries. The HomeGen 7000 uses PEM (proton exchange membrane) fuel cell technology. As well as 7 kWe continuous, other specifications include: a size of 75in long x 35in wide x 55in high; efficiency of 29 per cent at 7 kWe (simple cycle) and a cogeneration efficiency of over 75 per cent; fuel cell operating temperature of 160°F and exhaust temperature of 220°F; power quality IEEE 519 or better; NOx and SOx both less than 1 ppm; maintenance intervals of 8000 h (routine), 40 000 h (major components); design life of 15 years; and noise less than 65 dBa at 1 m.