Then you don't understand how power works.
All generators, machines, storage units take and receive power in "packets" of some variable size. Solar panels output packets of size 1, regular coal/charcoal/fuel generators output in packets of size 10. As packets travel down cables, they lose energy at a certain rate, but packets only carry integer-sized amounts of energy, so no reductions occur until you incur a single loss of 1 EU/p (or more). In the case of (insulated) copper cable, you lose .2 EU/p/b, which is to say that for every packet that travels through the cable, you lose .2EU per block of cable. Since Solar Panels output at 1EU/t (or 1EU/p, though do NOT confuse the two) the current is only able to travel 5 blocks in (insulated) copper cable before losing all of its power. If you want it to make it through the copper cable, you need to put a batbox in front of the panel first before it goes to the machines, and before the 5-cable limit at which point the resistance is too high for the current to make it. Once it makes it past the batbox, it will be in packets of size 32EU/p, which can easily bridge the length of cable you've provided.
Alternatively, use tin cable, which can handle the output from solar panels (it has a limit of 5EU/p, Solar Panels are only 1EU/p) but unlike copper cable, they only reduce .025EU/p/b, which means that a 1EU packet can travel 40 blocks before losing all its power. Tin cable can't handle charcoal generators though (10EU/p) so you'll have to experiment and find an appropriate solution.
One more thing: Don't use Solar panels without a storage unit. You need a way to store energy overnight when the panel isn't working, or else if it starts to rain on the server.