When we moved into our current place the electric bill (‘hydro’ bill here in Canada) was unpleasantly high, nearly twice what we had previously been paying.
It turned out this 1.5x as large house had pretty much nothing but incandescent and halogen bulbs. A clean, well-lighted, but very inefficient space. So we have slowly but steadily been replacing the bulbs, especially the big BR40 bulb can lights, with LEDs.
This is not, actually, the smartest maneuver. Each of those bulbs costs $25, and you can run an inefficient bulb a loooong time for that much money. And, from an environmental point of view, it costs a lot more energy to make an LED than to just keep using the already-existing incandescent or halogen. If the embedded energy in the new bulb is, say, 500 kilowatts (this is just a random number; the actual energy costs from building the mining equipment to the extensive packaging to the costs of shipping are probably higher) then the new bulb (which uses 9w) has to run roughly 7 692 hours in normal use in order to save as much energy as it cost to build, when compared with the previous 75w bulb.
Another comparison is how much a kilowatt costs me. My rate supposedly is $0.0858 per kwhour. Since the new bulb is saving me 65w per hour, I save 1 kwhour for every 15.38461538 hours the new bulb is used. The cost of the lightbulb is equivalent to 291.37529138 kwhours. If I use the new bulb for only 4 482.69678912 hours then I will have saved as much money as the new bulb cost.
Unfortunately very few of these light bulbs are on more than a few hours a day. It will be three or four years, at least, before they break even for me, and another 5-10 years or more before they save as much energy as they cost to make. Clearly this whole project makes no sense!
Although the cost savings to me at the current rates will take many years to break even, the rate goes up every year so it will likely pay off faster than predicted. But part of the steady increase in electricity rates is to pay for system improvements to meet rising demand – but if I reduce my consumption (and the community on average also reduces consumption) then we might not need to have electricity rate rises so rapidly; that will ultimately save me even more money than just reducing my consumption now.
My metro region has seen population increases of around 3% annually for more than a decade. (The metro population nearly doubled, 197.75%, between 1981 and 2011 the most recent statistical year.) But the region’s electrical consumption has actually decreased slightly over the last decade as lighting, appliances, heating and insulation systems have become more efficient. When you think about it Vancouver is actually pretty mind-boggling – a growing city with near-stagnant energy consumption.
But, ultimately, my purchasing these light bulbs is an investment in the future of this house. And I do not own this house. I am not going to take all these bulbs with me when I move out, either – at least I sure hope I am never going to live in another barn of a house with a zillion big recessed can lights! The big benefit for me is the smaller electric bills for the remaining months I am here; I will never save enough to pay for this investment, but I will have more spare money then than I have now.