I looked into those during the past year. It is amazing that CHP (combined heat and power units) from that manufacturer were showing up on the surplus market that were pulled early in their life. See: http://www.globalmicroturbine.com/Site/ ... rbine.html
It "seemed" that the units were not "that" commercially viable. I called for pricing on the "surplus" units... you need a high pressure natural gas compressor that was almost the price and size of the CHP unit. My personal conclusion was that it wasn't ready for prime time investment with my $'s. Here is a reasonable write up of an installation of 10 Capstone CHP units at a landfill: http://www.ornl.gov/sci/de_materials/Mc ... tation.pps
Note it closed on ROI in less than three years, but that was with VERY substantial subsidies for installation and free fuel from the landfill. Your mileage may vary.
I have been a firm believer in CHP since around 1978. My calcs from the 70's reinforced my revised calcs during the past year from doing a life cycle financial analysis, the ROI (return on investment) isn't there yet. Maintenance $'s per run hour is always the killer in the calc for small scale Co-Gen or CHP mini plants. The capstone turbines have some very expensive/exotic high temperature materials in them to get the efficiency up. Before this economic catastrophe I was consulting a bit with a developer on a residential cluster development with a centralized CHP infrastructure... but he is currently in dire financial straights, so that dream will never see reality in my lifetime.
It is my feeling that CHP is viable at around the 7,000KW range and very viable around 25,000KW in a commercial/industrial environment. I have never been able to make the ROI close for a residential application where you must pay residential rates for the fuel, and pay for maintenance.
bigMoose's electronic pieces & parts (GENUINE IRFB4110Pbf's, Nomex 410, AntiCorrosion Grease, Current Sensors) available HERE.
Thanks to Justin ebikes.ca
for securing the board then setting us FREE! Tech Tips in the WiKi: http://endless-sphere.com/w "Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God..." all the best, Dave