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.
You should check the name plate on the stove to find out the wattage of the stove. If this is not feasible then look in the manual that you got with the stove. Then use the formula, Watts = amps x volts. Amps = Watts/Volts. The voltage going to a stove is usually 240 volts.10 AWG 3 wires + ground. Most electrical codes require a dedicated 50 ampere 240 volt circuit for a kitchen electrical range (#6/3 cable).A 30 ampere circuit would be suitable for a series of outlets that powered cooking appliances such as microwave oven, counter top toaster oven, electric roaster, etc..ou should check the name plate on the stove to find out the wattage of the stove. If this is not feasible then look in the manual that you got with the stove. Then use the formula, Watts = amps x volts. Amps = Watts/Volts. The voltage going to a stove is usually 240 volts.