The running costs for 10 normal light bulbs running 4 hours a day will be £102.20 per year in electricity. 10 of our LED light bulbs running 4 hours a day will cost £8.17 per year in electricity, whats more our LED light bulbs last 20 times longer than normal bulbs & all come with a 5 year warranty.Take a look at www.ledwholesaleuk.co.uk.