This week we were shooting at a location without power readily available so looked to generators for a solution.
After some research on the web we decided it would be a bad idea to use any old generator for fear of voltage spikes and damaged flash heads.
I took 2 Bowens Gemini 500w heads along for us to test with. With both heads running at full power we were pulling roughly 13amps for a second or two whilst the heads recharged.
We then added extra load via a load bank to simulate the Apple G5 powermac and screen I wanted to use.
The upshot was that the generator handled 2 heads and the extra load with no problems at all.
During the shoot we were using the following kit from the generator with no issuse:
Bowens Gemini GM500 heads x2
Apple Mac G5 dual 2.3GB Pro tower
Apple 20" HD cinema monitor
Lacie External Hard-drive
Powered speakers
For the third flash head which was used at various points we used a Bowens Travelpak.
The generator was running from roughly 9.45am through to 18.00 with a sustained shooting time of roughly 3 hours. The generator only used half a full tank of fuel which was approximately £10.00.
It is advisable to use a generator only in a well ventilated area.
These are only my personal experience of using a generator with flash heads. Please ensure you test your kit thoroughly and always take advise from the manufacture when using equipment for purposes other than that it was intended for.
Below are the main images from the shoot:

Models (top to bottom)
Marita Oakes
Louise Birkhead
Monika Godlewska
Hair & Makeup
Emma Fairfield
Richard Beaumont
Wardrobe / Styling
Natasha Lyons
Special thanks to Guy Rusling for the use of the space.
Special thanks to 93ft Design for the use of their meeting room for make-up and hair.
Special thanks to Jonathan & Kevin for assisting.