Extension pole - extra wide 380mm for rental property

Hi there. Our rental apartment has no window covering in the living room. I don't think we can expect the landlord to put up curtains or blinds. I'm happy to provide some kind of cheap window covering myself but I'm struggling to find a wide enough tension rod that won't damage the walls. Does anyone know if these are available? Just some fine lightweight voile or similar fabric would help block out the fierce Westerly afternoon sun.