Help please, my maths is terrible!

ANGLICANPAT

Hi
Im just looking at the accounts for daughters service charge for her flat. The total bill for 3x150ww lights in the communal hall is, for 12 months, is nearly £200. Trying to calculate if this is reasonable. The lights switch off automatically about five minutes after they are activated . I think Im vastly overestimating in allowing that the lights might be on 12 hrs a day overall.
Ive tried to work out on that basis what wattage would be being paid for, but Im now in the millions so Ive gone wrong somewhere. No calculator available, what would be an average expected cost for my scenario please?

notbritishgas

Using your figures and times.
0.45kw used each hour,
0.45x12hours=5.4kwh
5.4x31days=167.4kwh
167.4x9months=1506.6kwh
Assuming electric is 10p perkwh then total cost =£150.60.

However, is the sevice cost just for the communal lights and is your daughter paying all of it. Is 12 hours per day a lot for the lights to be on?

Ah I see you have just edited your post to 12 months so
167.4 x 12months =2008.8
So cost at 10p per kwh = £200.80.

JimmyTheWig

So in 12 months it would use 1971kWh.

British Gas' Standard tarriff for my postcode is 23.022p per kWh for the first 670 kWh per quarter. All of this, therefore, would be charged at this rate and so they would charge 1971 x 23.022p = £454.

In which case £200 is a bargain!
(Assuming that this is what the management company are paying for electricity, not what your daughter is being asked to pay.)

Premier_2

ANGLICANPAT wrote: »

Hi
Im just looking at the accounts for daughters service charge for her flat. The total bill for 3x150ww lights in the communal hall is, for 12 months, is nearly £200. Trying to calculate if this is reasonable. The lights switch off automatically about five minutes after they are activated . I think Im vastly overestimating in allowing that the lights might be on 12 hrs a day overall.
Ive tried to work out on that basis what wattage would be being paid for, but Im now in the millions so Ive gone wrong somewhere. No calculator available, what would be an average expected cost for my scenario please?

Are you sure that is all the communal electricity is used for?

Typically there may be sockets that cleaners access for cleaning communal hallways and/or other electrical appliances such as television signal amplifiers/distribution systems, smoke/fire alarms systems, entry phones systems, etc.

What you are asking for (the wattage consumed) should be something the management company should be prepared to provide on request (it may include a catch up amount based on previous estimated bills)

Whilst your requesting the info, I would suggest you also request the unit charge(s) the management company pay, whether or not it is on a residential or business tariff (you may have an opportunity to challenge this if not residential), any standing charge that may apply ... in fact all details of the tariff involved.

Actually, communal lighting is a good example of when an E7 tariff may be a better solution. (depending on how much you think they are on during the off peak period) - when I lived in a flat, the communal lights were on continuously (no movement sensors) from dusk to dawn and E7 saved us a fortune.


Edit: actually, in your case, if you think the lights are on 12 hours per day with movement sensors, then it sounds like they probably come on any time of the day (no windows?). In which case it may be prudent to suggest the bulbs are replaced by energy saving bulbs. Currently, most are not suitable for use with movement sensors, so perhaps get that over-ridden - even if the lights are kept on 24hours per day, with energy saving bulbs buy could reasonably expect electricity consumption to fall by 60% compared to being on just 12 hours per day currently.

notbritishgas

JimmyTheWig wrote: »

So in 12 months it would use 1971kWh.

British Gas' Standard tarriff for my postcode is 23.022p per kWh for the first 670 kWh per quarter. All of this, therefore, would be charged at this rate and so they would charge 1971 x 23.022p = £454.

In which case £200 is a bargain!
(Assuming that this is what the management company are paying for electricity, not what your daughter is being asked to pay.)

Normally Bg charge the first 125 per qtr at the high rate for electricity.
The gas charge is for 670kwh per qtr.
When I assumed 10p per kwh I thought other electricity would be used to use up the high units.

ANGLICANPAT

Thanks nbg Jimmy and Premier . Looks like the amount might be around right then. I did think 12 hrs a day that I 'allowed' was well over the top as none of the flats do comings and goings between 11pm and 6am , and theres not that much activity the rest of the day either really, but on the other hand , I had forgotten about sockets - yes the cleaner access one just once a week, and I also forgot the fire alarm - and have no idea about TV's and stuff. My daughter pays one third of this, so looks like the bill is ok. Will ask for more info from manager next time.
Thanks again.

Owain_Moneysaver

Bear in mind that some building factors have a tendency towards supplying lightbulbs at a rather inflated resale value.

Tesco have energy saving bulbs for 10p each at the moment. 450W in a communal hall is obscene. You could light a tower block for that.

ANGLICANPAT

Hi Owain - I should have been clearer, the three lights are on three different sections of communal areas .