I want to know the answer to the following question:
When did Tucson's main power plant begin operation?
All the background I'm provided with is that "Tucson's primary electrical power source is a coal and natural gas power-plant managed by Tucson Electric Power that is situated within the city limits on the south-western boundary of Davis-Monthan Air-force base adjacent to Interstate-10.". Is that enough to answer the question?
Answer: no