Shelley was a key member of a close circle of visionary poets and writers that included Lord Byron; Leigh Hunt; Thomas Love Peacock; and his own second wife, Mary Shelley, the author of Frankenstein.
If the 900 watts means the input power, then 1000 w inverter would be ok. If the microwave produces 900 w of cooking power, you will need a bit more, maybe 1200-1400 w if you don't know what the input power rating of the microwave is.
Multiple lights and most outlets can be run on a single circuit. But devices such as microwave ovens, cooktops, ovens and clothes dryers require a dedicated circuit. Here are a few rules of thumb when thinking about the electrical requirements in your house: 1. Wire size is counterintuitive.