This time of year there seems to be a lot more power outages than normal, usually driven by weather extremes. Before and after xmas I found quite a few 'bargains' at the usual chain stores and electronic shops that would provide basic cooling and lighting systems as well as keeping laptops and mobile phones charged for example.
If you own a car than the $17 Car Powerpoint 150Watt 'can inverter' I picked up from Aldi just plugs in to the Acc socket. Run an extension lead into the house and hook a power strip on the end. Lots of portable fans and table lamps with CFL globes will run for hours off the car battery provided you keep it charged with a $30 car battery charger when the power is on.
A little further along the shelf I found a 600W inverter for $40. Now this needs a more serious battery like a 75-100Ah 12V SLA for $200. I fitted some heavy duty battery leads to mine to test it and it was able to run a hair dryer on low using 45 Amps, or 450W, for a few minutes no problem. A battery charger as before will keep it ready for use in blackouts and a single 40W floor fan and a 15W table lamp will use around 5 amps while running, which means at least 8 hours operation. A laptop could be kept charged as well.
Basically every 10 Watt device works out to around 1 Amp drawn from the 12V battery after inverter losses are taken into account. So if you ran 2 X 40W fans and 2 X 10 Watt CFL lamps you would have a total current draw of about 10 amps from a 12V battery. So even though the 150 Watt 'can inverter' would cope with these loads the poor old average car battery would probably last only 2-3 hours.
A 40Watt solar module is around $150 and a regulator to prevent overcharging should cost no more than $50 if you want an independent charging system. This charges the battery at around 2.5 Amps in full sun. It really is easy to do this these days.
