I've done several different things as well, but not what AcesOyster is suggesting. I'll have to try that out. I've rigged up a charging station using a planter, harvester, aqueous accumulator and powered furnace to power steam dynamos. I use the planter to replant trees (preferably not oak as you have to set up a place to route the apples) and the harvest obviously cuts the down when grown. Using pipes from thermal expansion I route all of the saplings back into the planter and the logs to the powered furnace to be smelted into charcoal, which then is routed to the dynamo. The aqueous accumulator is used to supply endless water to the dynamo. One steam dynamo powered all of the machines as well as charged a couple of hardened energy cells.
I also have created an infinite bone meal source by using a pulverizor and cyclic assembler and white wool. The bone meal can be used in bioreactor to create biofuel for the biofuel generator. You could aslo set up a skeleton grinder and use the bones from that as well, but I wanted something more compact and less noisy.