Using two types of fuels (e.g., electricity and natural gas) to perform work.

In the case of combined electric and natural gas pumping facilities, several types of configurations are possible:

    • One pump connected to a gas engine and an electric motor using a combination drive;


    • A natural gas engine and a electric motor connected to individual pumps but drawing from the same sump or water source; or


    • One engine with both diesel and natural gas flowing into the same engine.[1]


[Source: Southern California Gas Company, 2013]