I have no idea how you arrived at $2.6, when i do the same calculation i end up with $6,48
45W for a month is 32.85 KWh (452430.4/1000), so i rounded up to 33 KWh.
Electricity where i live is currently averaging about €0.54/KWh, though this winter has seen prices as high as €1.14/KWh. Normal price is around €0.3.
33 * 0.54 = 17,8 ~= €18