Generator: 10 EU/t from fuel (coal 4000 EU, wood 750 EU).
Geothermal Generator: 20 EU/t from lava (bucket or 
Lava Cell = 10,000 EU).
Crafting Table3 × 3
1 × Generator
Crafting Table3 × 3
1 × Geothermal Generator
Solar Panel: 1 EU/t in daylight with open sky.
Wind Mill: higher and more open = more; rain and storms help.
Water Mill: surrounding water gives a little power, a water bucket in the GUI 1000 EU.
Radioisotope Thermoelectric Generator: 1–32 EU/t with 
pellets that never run out.
Crafting Table3 × 3
1 × Solar Panel
Crafting Table3 × 3
1 × Wind Mill
Crafting Table3 × 3
++++1 × Water Mill
Crafting Table3 × 3
1 × Radioisotope Thermoelectric GeneratorCompact solar arrays: 8 of one tier in a ring (centre empty) = 1 of the next tier.
Low Voltage Solar Array 8 EU/t (LV) · 
Medium Voltage Solar Array 64 EU/t (MV) · 
High Voltage Solar Array 512 EU/t (HV).
Like the solar panel: daylight, open sky, no rain. Careful: MV/HV output blows up LV machines — MV array → 
LV Transformer (128 → 32); HV array → 
MV Transformer (512 → 128), plus an LV one for LV machines; from 512 EU use gold, HV or glass fibre cable.
Crafting Table3 × 3
1 × Low Voltage Solar ArrayRequired materials
Solar Panel8 ×
Crafting Table3 × 3
1 × Medium Voltage Solar ArrayRequired materials
Crafting Table3 × 3
1 × High Voltage Solar ArrayRequired materials