Does 32GB of RAM significantly affect your power bill?

No, not in any way you’d notice. RAM is efficient—each stick draws 3-5 watts under load and less than a watt at idle. Jumping from 16GB to 32GB adds 2-4 watts when using that extra capacity, which is negligible compared to a CPU or GPU. On a laptop, the battery hit is 2-3% in real-world use; on a desktop, you’ll never see a difference on your electric bill.