I know that sounds ridiculously small, but it's advantage is that when it runs with no load, it's using very little power.

The circuit I wanted to run from it is a few lights and these are CFLs.  I've checked the inverter with CFLs and it runs them witout any problems.  Because the CFLs are such low wattage, I can run quite a few (upto the 150w max) but I realise that it's not exact in that I can't run 15 x 10W.

Thanks for all the replies so far, a lot of very helpful stuff in there that has nade ne think about the issues.