February 7, 2013

LED Light Bulbs Now Cheaper than CFLs in Long Run

For quite a while LED bulbs have been too expensive to warrant the purchase and not really cost effective over CFLs.   When I looked at LED light bulbs last spring I concluded that LED bulbs were still too expensive.   At that point the LED bulb I looked at was 'under $19'     But today that same bulb is $16.09.   As I assumed in that article over time prices for LED bulbs are coming down.   There are also LED bulbs cheaper than that in the $11 range depending on size and application.   With LED prices coming down I decided to take another look and see how they compare to CFLs (compact fluorescent lamps).   

I'll look at three different applications.   To compare the costs I'll first just add up the cost of the bulbs and the cost of electricity assuming 10¢ per kWh.  I'll also then do a NPV (net present value) comparison.  I will ignore inflation so this isn't a perfect analysis but good enough to get a basic idea of the numbers.

First lets look at a standard 60W equivalent bulb 

CFL :GE 13-Watt Energy SmartTM - 8 Pack - 60 watt replacement
Cost : $1.49, Watts : 13, Life : 8,000 hr
LED :Lighting EVER 7W A19 LED Bulb, High Performance Samsung LED, Daylight White, 60W Incandescent Bulb Replacement
Cost : $10.88, Watts : 7 : Life : 30,000 hr

To make the math a little easier lets assume 7500 life on the CFL and assume you need 4 of them to last as long as the LED.

CFL : 4 bulbs x $1.49 +  30000 hr x 13 W / 1000 kW/W x $0.10 kWh = $44.96
LED : 1 bulb x $10.88 + 30000 hr x 7 W / 1000 kW/W x $0.10 kWh = $31.88

Now I also did a NPV calculation assuming 4% discount rate and came out with NPV of $26.89 for the LED and $35.35 for the CFLs.    This is because you're spending more of the money today with the LED so its not quite as favorable when you look at present versus future costs of money.   But I did a simple figure and didn't account for inflation of electricity or bulb costs so its not perfect.

Lets compare candelabra bulbs.

CFL :GE Cfl Candelabra Bulb (00373)
Cost $6.75, Watts 5, Lifetime 6000 hrs

LED : 2 Pack Ge 1.8-watt Led Candelabra Base 75-lumen Decorative Bent Tip Light Bulb, Clear
Cost : $14.55, Watts 1.8, Lifetime 12000 hrs

If you want 12,000 of light then you can buy 2 x CFL or 1 x LED.   Total costs would be :

CFL : 2 bulbs x $6.75 + 12000 hours x 5 watts / 1000 kw/W x $0.10 /kWh = $19.50
LED = 1 bulb x $14.55 + 12000 hr x 1.8 W / 1000 kw/W x $0.1 /kWh = $16.71

For this example the LED is cheaper in total cost.

NPV would be $15.68 for the LED and $16.31 for the CFLs.   LED still wins.

Now let us compare flood lights for recessed can lighting

CFL :GE Energy Smart CFL 72984 15-Watt, 750-Lumen R30 Floodlight Bulb with Medium Base, 2-Pack
Cost : $7.99, Watts 15 : lifetime : 10,000
LED : LED Light Bulb, 900 Lumen, Warm White, 9 Watt (65W Replacement) by G7 Power 
Cost : $16.09, Watts : 9, lifetime : 30,000 hr

CFL = 3x $7.99 + 30,000 hr x 15W / 1000 W/kW X $0.10 kWh = $68.97
LED : 16.09 + 30000 hr x 9W / 1000 x 0.1 = $43.09

NPV numbers are $52.54 for the CFL and $35.48 for the LED.

Note these bulbs are not exactly the same in shape and size.  However the LED specs. claim its a replacement for recessed lighting and R20 size bulbs.  It will be a little smaller than the CFL version, but I couldn't find a direct equivalent CFL to LED for this application.

In both cases the LED's are cheaper over the life of the bulbs.

In all three cases I looked at here the LED comes out on top.   However if you change any details then the CFLs could easily be cheaper, it still depends on the specifics.   It seems if you are willing to take the leap to LEDs then it is worth it financially.    I think I'll still wait on buying LEDs until they're a little more proven.   They claim long lifetimes and I expect thats realistic given LED technology but I think I'd like to wait and make sure the technology is proven.   Plus if I wait a little longer I expect LED prices will drop even further.

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