Why it’s really not worth arguing over leaving the lights on
Wasted energy doesn't always result in much larger bills
Lauren Almeida,
SENIOR MONEY REPORTER
18 January 2024 • 2:40pm
Leaving lights on in empty rooms is the most common argument that families have over their household bills, despite the energy-wasting habit costing less than £2 extra each year...
That's a bit deceptive. I quickly checked and got a figure of around £25.
So working backwards, I had to assume the lights weren't on during the day(light). Are switched off over night. And we are really just talking about room lights left on as folk move from room to room.
So I got 2hrs per day (when the room light is on, but nobody in there), a single 9W LED, = 6.57kWh pa, and leccy at about 30p/kWh = £1.97.
But that is per room.
8.7kWp PV [2.12kWp SSW + 4.61kWp ESE PV + 2.0kWp WNW PV]
Two BEV's.
Two small A2A heatpumps.
20kWh Battery storage.
Mart wrote: ↑Fri Jan 19, 2024 5:57 pm
That's a bit deceptive. I quickly checked and got a figure of around £25.
So working backwards, I had to assume the lights weren't on during the day(light). Are switched off over night. And we are really just talking about room lights left on as folk move from room to room.
So I got 2hrs per day (when the room light is on, but nobody in there), a single 9W LED, = 6.57kWh pa, and leccy at about 30p/kWh = £1.97.
But that is per room.
I remember Nowty posted a good while back regarding the negligent cost of lights. It kind of hit me as I'm very much from the school of turn it off.
Got 6 lights running in family room, big lounge and hall. Run the Dubai similars @ 4W per. Combining with IO @ 7.5p per KWh and a 14hr Winter day we are .0.075x1000x24x14=????
2 52p per 14hrs across 3 rooms. That can't be right?
£9.22 on a leap year across three room lighting.
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
Bugtownboy wrote: ↑Fri Jan 19, 2024 6:24 pm
But, isn’t it a principle of if you’re not using/needing it, switch it off ?
Sure there are times where ‘switching off’ is not the best option , but surely, with LED’s, it has to be the right approach ?
Otherwise, it’s one less grump for the more mature male.
Indeed but my 2 beer rejoinder would be something like this, "Winter is miserable, isn't it nice to have Casa lighted well".
Just a thought...
As another thought, we had a 2kWh PV day today. A bit of panel clearance in the morning, good fun. That wee amount of PV input would fuel the 6 light combo for 595 hours. can't get my head around that!
Last edited by Joeboy on Fri Jan 19, 2024 6:36 pm, edited 1 time in total.
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
Bugtownboy wrote: ↑Fri Jan 19, 2024 6:24 pm
But, isn’t it a principle of if you’re not using/needing it, switch it off ?
Sure there are times where ‘switching off’ is not the best option , but surely, with LED’s, it has to be the right approach ?
Otherwise, it’s one less grump for the more mature male.
I thought that incandescent lights ought to be switched off whenever not needed (but at least the wasted energy does heat the house a bit - albeit expensively) but LEDs use so little power that shortening their lives by repeated switching was an own goal, both in respect of price and embodied energy?
2.0 kW/4.62 MWh pa in Ripples, 4.5 kWp W-facing pv, 9.5 kWh batt
30 solar thermal tubes, 2MWh pa in Stockport, plus Congleton and Kinlochbervie Hydros,
Most travel by bike, walking or bus/train. Veg, fruit - and Bees!
MoD’s £10-a-shot laser beam which will ‘revolutionise warfare’ fired for first time
The DragonFire weapon is being developed to hit missiles and drones, and was successfully fired at aerial targets during a trial
How much Dooo the MoD pay for 1 kwh
How many kwh is there in £10
can't get my head around that!
