If you look back over my posts from this summer, you’ll find energy has been a theme. I’ve talked about electric cars vs gas ones, I’ve discussed electricity vs gas and diesel, I’ve talked about different units for measuring power, etc.<\/p>\n
To someone gaining interest about the general topic of energy, an inevitable question is, “What is the energy use of a given device in my home? What does it cost to run?”<\/p>\n
I’ve chosen a couple of devices pursuant to this discussion: my little laptop computer (which uses low power), and my wife’s hairdryer (which uses much more power).<\/p>\n
The power supply attached to the laptop says 65W, which is 0.065kW. Therefore, running it for an hour uses 0.065kWh. BC Hydro,<\/a> which is the electrical utility here, has a stepped rate: over a two month period, you are billed as follows:<\/p>\n Usage above 1350kWh is billed at 11.27 cents\/kWh.\n<\/ol>\n Assuming I’m within my first 1350kWh this billing cycle, running my laptop for an hour will cost (0.065)(7.52)=0.4888 cents: about half a cent. Running the computer non-stop for 30 days will cost about $3.50. It’s only on about 4 to 8 hours per day; let’s call it 6 hours. Then the monthly cost is about 90 cents. BC Hydro’s billing cycle is two months, leading to $1.80 on the bill due to laptop use. <\/p>\n Now, let’s check out the hairdryer. It uses a whopping 1875W, or 1.875kW. Using it for an hour costs 14.1 cents. (This assumes, once again, I’m within the first 1350kWh.) Using it non-stop for 30 days would cost about $101.50. I’d say my wife actually does use it about 4 hours per month; for that, we’re on the hook for about 56 cents: $1.12 for a two-month period.<\/p>\n With a bill of $1.80 +$1.12=$2.92 for the laptop and hairdryer, one starts to get a picture of where the money is going. Note the computer, while it uses only about 1\/29 the power of the hairdryer, actually costs more to run per month because of usage habits.<\/p>\n For more about household energy consumption, and the divergent topics to which it might lead, please come visit again:)<\/p>\n\nFor the first 1350kWh you use, the rate is 7.52 cents\/kWh.<\/p>\n