If its struggling on Gas, it will be worse running on 12V or 240V. The main problem in Australia with 3 way fridges is they need to be T rated (Tropical). If they aren't then the cabinet insulation is not good enough at those temperatures. 12V compressor fridges are far better here in Australia with high temperatures. 2 main contenders for upright 12V fridges here are Waeco & Engel. I run an 80Liter Waeco upright fridge in my van off 100W Solar system, this will keep fridge temps under4Deg C, in amb temps of nearly 50deg C.