Question: how much do christmas lights increase electric bill?
Answer: A comparable string of C9 LEDs, by contrast, uses just 2.4 watts and costs 21 cents to run over the same period. The price differential for the smaller mini-bulbs is less extreme but still significant: 100 incandescent minis will cost about $3.53 to run for one season, while LED minis will cost just 41 cents.