Yes, that's £0.36 per day. Incidentally, you brits sure pay a lot for electricity. Here in the states, it's less than half that.

250 watts = 0.25 kilowatts, NOT 0.25 kilowatt hours. big difference. kilowatts are a unit of power, like watts. kilowatt hours are a unit of energy. power is the rate at which energy is used.

Unless you have a really crappy ballast, it probably generates about 50 watts of heat, making your total lamp usage more like 300 watts. This makes the cost more like £0.43 per day.
khronik Reviewed by khronik on . help please hi all, 250w hps 12 hours @ £0.12kwh will cost £0.36 (250w x 12 =3kw x 0.12kwh= 0.36) are my calculations correct????????????please can someone tell me!!!!! i heard on other posts a 250w actually consumes 450w or something is this true.......i was told 250w is 0.25kwh so im really confused and would really appreciate any help morning glory Rating: 5