This document discusses reciprocating engines and natural gas engine generators. It notes that reciprocating engines can provide 10 MW of power capacity with a 20-40% capacity factor, good part load heat rate, black start capability within 5 minutes, and reactive power and frequency support. It lists some manufacturers that make natural gas engine generators between 3.6-9.3 MW. Reciprocating engines are needed because the sun doesn't always shine and the wind doesn't always blow. Benefits of natural gas engine power projects include multiple shafts, minimal degradation from air temperature or altitude, near zero water usage with radiator cooling, and combined heat and power potential. Examples of large scale natural gas reciprocating engine plants are shown on