Cogeneration & On-Site Power Production, May/June 2014, by Michael Devine.
http://www.cospp.com/articles/print/volume-15/issue-3/features/more-than-heat-and-power.html

"Cogeneration today goes well beyond simultaneously generating electricity and hot water or steam. Today's usable engine outputs can also include heated air, chilled water produced by absorption chillers, and carbon dioxide from purified exhaust. In other words, a single engine-generator can produce two, three or four useful outputs at once. With today's generating technologies, electrical efficiencies up to 45% and total resource efficiencies upwards of 90% are achievable. And cogeneration systems do not necessarily need to operate full-time at full load to be cost-effective–low-cost and low-intensity configurations can bring attractive returns in many settings."