Terms of the contract were not announced.
The plant will serve as a reference that will be used to provide a design package to power plant developers worldwide, the companies said in a joint statement.
Fluor said it would immediately begin studies on optimizing performance, construction and cost for eSolar's solar thermal technology.
eSolar's power plants use mirrors to reflect the sun's heat onto a tower where water is heated. Steam from the heated water powers a turbine to create electricity in much the same way conventional power plants do.
The Pasadena, California, company builds its power plants in prefabricated modules, allowing for the addition of more modules later.
eSolar opened its first 5 MW plant in Lancaster, California, earlier this month. The privately held company in February struck a deal with power plant owner NRG Energy Inc to develop 500 MW of solar thermal power plants.
Fluor, which is based in Irving, Texas, set up a renewable energy business line in May.