Doing the Math on LED Lightbulbs, part 2
In my previous journal entry I showed example calculations of how much money LED bulbs save in electricity costs versus traditional, incandescent bulbs. Depending on assumptions about how often lights in the house are used, the savings could be anywhere from several tens of dollars to a few hundred dollars per year. That's a fair chunk of change. But there's more to consider before rushing to buy LEDs to replace all the lightbulbs in the house.
One big factor is the cost of bulbs. LED bulbs cost more than incandescent bulbs. Thankfully the cost differential is not as severe as it used to be. A few years ago LEDs were 5-10x the price of incadescents. The wisdom about buying LEDs was that it would take years of using the bulb to save enough on electricity costs break even on its purchase cost. Indeed, the math I showed yesterday bears that out. When 6 bulbs cost $100 to purchase and save just $22/year used 1 hour/day, you break even after 4.5 years. Today the cost differential is 2-3x, which is a lot easier to swallow- and a lot quicker to break even on.
But even break-even time is not the end of the story. While LED bulbs do still cost more to purchase initially they last a heck of a lot longer. The bulbs we installed are rated at 25,000 hours lifetime versus 2,000 for the bulbs they replaced. While LEDs cost 2-3x initially each could last as long as 10-12 incandescent bulbs. That makes LEDs a purchase-price bargain in addition to being a cost-of-electricity bargain. It's a win-win. It's just that both wins add up only in the long term.
Finally there's the question of whether we rush out now to replace all the bulbs in the house. We could save money on our electrical bills by doing so, but the amount doesn't seem that compelling. Then too, throwing away incadescent bulbs that still work is not necessarily a good thing for the environment. It seems more prudent simply to swap in LEDs for the old bulbs as they wear out.
One big factor is the cost of bulbs. LED bulbs cost more than incandescent bulbs. Thankfully the cost differential is not as severe as it used to be. A few years ago LEDs were 5-10x the price of incadescents. The wisdom about buying LEDs was that it would take years of using the bulb to save enough on electricity costs break even on its purchase cost. Indeed, the math I showed yesterday bears that out. When 6 bulbs cost $100 to purchase and save just $22/year used 1 hour/day, you break even after 4.5 years. Today the cost differential is 2-3x, which is a lot easier to swallow- and a lot quicker to break even on.
But even break-even time is not the end of the story. While LED bulbs do still cost more to purchase initially they last a heck of a lot longer. The bulbs we installed are rated at 25,000 hours lifetime versus 2,000 for the bulbs they replaced. While LEDs cost 2-3x initially each could last as long as 10-12 incandescent bulbs. That makes LEDs a purchase-price bargain in addition to being a cost-of-electricity bargain. It's a win-win. It's just that both wins add up only in the long term.
Finally there's the question of whether we rush out now to replace all the bulbs in the house. We could save money on our electrical bills by doing so, but the amount doesn't seem that compelling. Then too, throwing away incadescent bulbs that still work is not necessarily a good thing for the environment. It seems more prudent simply to swap in LEDs for the old bulbs as they wear out.