From RimWorld Wiki
While the refinery is selected, click "Bills" then "Add Bill" to add an order to produce chemfuel:
- Make chemfuel from wood: Turns 70 wood logs into 35 chemfuel.
- Make chemfuel from organics: Turns 3.5 nutrition worth of food ingredients in 35 chemfuel.
- Hay is not accepted.
- Most raw ingredients have a nutrition value of 0.05. For such ingredients, 3.5 nutrition requires 70 units, which is the same quantity required of wood.
- Meals provide 0.9 nutrition each, so 4 meals is enough to "Make chemfuel from organics". This costs only 40 units of raw food, but requires extra cooking labor.
- Nutrient Paste meals are even more efficient (4 meals requiring only 24 raw food), and can be produced in bulk.
- Since chemfuel powered generators use only 4 fuel per day, it is very easy to achieve net power from a closed system. (A farm can easily fuel its own Sunlamps and still provide a surplus of food)