How Much is the Electricity to Run a Lightbulb?.
There are many factors to consider when giving an answer to that question: Size of Lightbulb, Type of Lightbulb, Energy Supplier, Do You have Solar Panels, etc.
This question came to mind today, while looking at my kitchen light, as my kitchen aspect is poor for natural light, and we have a lightbulb on for the majority of the time. I ended up wondering what it costs us per year, and should we install a ceiling skylight. (About $125 + fitting)
We have a 19w 2300 Lumen LED light, equivalent in output to about 150w in old style bulbs, and it runs for about 12 hours per day.
I calculated the power consumed at 12 hours per day, 365 days per year by 19w and that came to 83,220 watts per year, or 83.22 kWh.
Our 19w LED bulb used for 12 hours per day at standard QLD electricity rates (28c per kWh) would cost $23.30 per year.
Our 19w LED bulb used for 12 hours per day at Alinta Energy “paid on time” rates (20.2c per kWh) would cost $16.78 per year.
Our 19w LED bulb used for 12 hours per day with Solar Power and with Alinta Energy Solar Rebate (11c per kWh) would cost $12.97 per year.
A standard 150w bulb for 12 hours per day at standard QLD electricity rates (28c per kWh) would cost $183.96 per year.
A standard 150w bulb used for 12 hours per day at Alinta Energy “paid on time” rates (20.2c per kWh) would cost $132.45 per year.
A standard 150w bulb used for 12 hours per day with Solar Power and with Alinta Energy Solar Rebate (11c per kWh) would cost $102.36 per year.
The above Solar calculation assumes 6 hours in sunlight and 6 hours after the sun goes down, each day.
It also counts the lost sale of power to the provider, in my case at the 11 cents per kWh that they pay me for my excess power. I counted that as a cost to me of 11 cents per kWh.
So, for my Kitchen light, it is about $13 per year, but it would be half that, if we used a smaller bulb, such as 8w (or 75w old style)