Having had no power for 24 hours looking at generators, the one below
is probably fairly typical of portable generators:-


"Sealey Petrol Generator 800w 2hp 2 Stroke Engine

Compact and lightweight unit capable of running small tools and lights
etc. makes it ideal for roadside, building sites or leisure use.
Powerful and reliable generator fitted with maintenance free brushless
alternator. Fitted with 12V battery charging outlet and 230V 3-pin
socket.

Model No: G950
Motor Power: 2hp
Motor Type: 2-Stroke
Output: 230V - 50Hz /12V DC
Current Rating: 3A /8.1A
Cont. Power Rating: 650W
Max Power Rating: 800W"

Now, a fridge or freezer is only about 200W but I read this:-
"http://www.powersaving.co.za/index.php?q=con,50,%20misc"
The compressor (fridge) is a highly reactive load because when its
running the VA shoots up to more than twice the value of the watts
consumed. The relationship between real power (Watts) and apparant
power (VA), is defined by the ratio between them called the power
factor (which reached a minimum of 42% in this test). Unfortunately
this concept is fairly technical. The significance of the much larger
value of VA for the average home owner is that if you are selecting an
alternative source of power you need to check that it can provide
sufficient VA over and above its power rating in Watts or kilo Watts
(in this case the maximum values recorded were 145W vs 295VA).

this whistled over my head with a big WHOOSH, anyone know if the
example generator is likely to be powerful enough?
--
Mike