Answer:
coal
Step-by-step explanation:
Frank Schuman's solar power invention to create steam that will drive the turbine to generate electricity was not accepted in the United State back then because coal, a non-renewable energy source, was available for cheap and can easily be burned to generate steam.
Since the coal was readily available for cheap and back then, the deposit was huge to the extent that no one was thinking that it could get exhausted one day or the environmental pollution created through its burning, the invention of Schuman did not get the desired attention.