Gas Turbines

Gas turbines typically have high temperature exhaust in the 500-700C (932-1292F) range and represent 60% of the energy input that goes into the turbine. This high quantity, high temperature heat makes turbines excellent CHP candidates. These high temperature exhaust is why so many systems use heat recovery steam generators to power a heat recovery steam generator (HRSG) that can drive a turbine generator or provide steam to a district heating network. Gas turbines can range in output size from 10MW to 500+ MW of electrical output. GE has put together a good list where you can see the specs of the exhaust profiles and output for a bunch of different sizes.

The simple cycle gas turbine is the least efficient arrangement since there is no recovery of heat in the exhaust gas. Hot exhaust gas can be used directly in a process or by adding a heat recovery steam generator (HRSG), exhaust heat can generate steam or hot water. Gas turbines are frequently used in district steam heating systems since their high quality thermal output can be used for most medium pressure steam systems.  (US DOE)

For larger gas turbine installations, combined cycles become economical, achieving approximately 60% electric generation efficiencies using the most advanced utility-class gas turbines. In a combined cycle setup, the exhaust gas heat is used to convert water to steam that is passed through a steam turbine, which adds additional electrical capacity for the same amount of fuel. Organic Rankine Cycle units can also be used with gas turbines to create a combined cycle. Although they are generally less efficient that steam cycle units, they are more adaptable to load changes with the gas turbine and generally do not require makeup water. GE has a whole line of products dedicated to the gas turbine + ORC arrangement

Microturbines

Microturbines are essentially small versions of the gas turbines. Several manufacturers are have competing engines in the 25-250 kW range, however, multiple units can be integrated to produce higher electrical output while providing additional reliability.

Hot exhaust gas from the turbine section is available for CHP applications. However, most designs incorporate a recuperator in the turbine, which utilizes some of the exhaust heat, making it available in lower quantities and temperatures than traditional gas turbines. However, recovered heat can still be used for hot water heating or low pressure steam applications.