there are 3 main options, Power cells from RFtools, Flux networks, and Dimensional transceiver from Ender IO, Power cells are a bit expensive, taking 4 redstone blocks, a diamond, an emerald, and 2 prismarine (which can be made from nether quarts at an atomic reconstructure) these can be linked together using a power cell card, they do have a small amount of power loss if they're not right next to each other, but it's small. they also act as storage for power, each one adding 1,000,000 RF collectively, next is Flux networks, these can transfer MEGATONS of power, however, using them enmass will cost you lots of ender pearls. dimensional transceivers are very expensive, but can also transfer items, so they're good for quarries or such.