I usually invest a weekend doing a bunch of chunks and I am good for quite a long time. I don't like doing it daily because of the sawdust. I use a table saw because I like to use construction debris and cut around the nails. There are some guys that have fabbed up simple
wood chunkers with pto's or using powerful electric motors. I made a V-8 powered chunker once but it scared me. I prefer to keep my arms attached to my body.
With a powered chunker setup expect to reinvest 10-12% of your
energy production back into
feed prep.
I find dead branches to be a fast source of feed prep. The greens have fallen off and nature already sized the diameter, now you just need to size the length.
This is an area that needs a definitive solution and I hope to put together a
workshop on it in the future because it deserves a book on the subject. For now, search "wood chunker" on youtube to see what others are doing.