best libre webserver

hello i run 2 webservers both on raspberry pi's (raspbian with the non-free and contrid repo's disabled)
and as the pi uses non-free software to boot
i am trying to find a alternative

dose anyone know of a computer similair to the pi?
that has low power consumption and is around as powerfull?

the main reason i was using it was they only cost £3.60 a year
to run.