I am waiting for advanced machines for tekkit 2.0 too.
HV solar arrays are not overpowered, really only cost less tin, 16*32 solar and 16*32 tin cables is nor problem if you need 80 stacks of iron to create that.
If someone think that HV arrays are overpowered, so what about 1800EU/t Mark I nuclear reactor? http://www.youtube.com/watch?v=bboQThQxCtI&feature=related
Greetings