Saving money with LED outdoor lighting

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Are you interested in ways you can save energy and money? With electricity prices rising and the switch away from inefficient incandescent light bulbs, it makes sense to consider alternatives.  However, switching to Compact Fluorescent Lamps (CFL) or LED bulbs isn't so simple or necessarily cheap.  These more efficient alternatives differ in a number of ways:

• CFL and LED bulbs cost more than incandescent bulbs (often a lot more) for the equivalent light output
• CFL and LED bulbs don't produce the same color or full spectrum of light as incandescent bulbs.
• CFL bulbs contain mercury, not a very environmentally friendly choice
• LED bulbs are usually more efficient than CFLs, but are also more expensive
• CFL and LED bulbs often do not work with dimmer circuits (or even day/night sensors - see below)
• CFLs and LED bulbs last longer (often much longer), but their expected life can vary quite a bit.
• LED bulbs currently don't put out as much light as incandescent bulbs can (e.g. beyond 75 Watt equivalent), so might not be a good choice when you need a lot of light.
• LED lighting is very directional with bulbs containing many individual LEDs.  This means you may have to choose a particular packaging that is appropriate for your application.

As my porch light had just burnt out and I was out of replacements, I thought I'd go green and switch to LED outdoor lighting.  Given the higher cost of CFL and LED lights, it made sense to me to start with my lights that are on the most.  My outdoor lights are on 8-12 hours per day (an obvious first choice even if they are fairly low wattage).

My goal was to fully recover the cost of the new lights in 1 year or less (I came close).  Given that the bulbs should last many years, I'll be saving a significant amount of money in the long run.  Plus, I'm immediately saving electricity.  It is nice when you can be green while saving green.

This turned into two different mini-projects.  I first replaced my porch light and then later converted all of my outdoor lighting.  I also learned a bit in the process.  I'll share how I did it and I have lots of pictures for you to enjoy.

Project #1:  Outdoor (120V) porch light

Lesson one:  LED bulbs (and also CFLs) don't like dimmers.  That is one of the first things that I read about when looking for a light for my porch.  I did have a day / night sensor on my porch light, but I assumed it would be okay (I was wrong!).

For my porch light, I looked for a bulb that would be a direct replacement for the 15 Watt incandescent bulbs I had been using (and replacing frequently).  I wanted a bulb that had a "warm white" look to the light (not the usual bluish light typical of LEDs).  I found this bulb from Lights of America which was perfect for the job and only uses 2 1/2 Watts

Well, after about a week the light bulb burnt out - not a good sign.  Good thing I had a spare!  After a second bulb burnt out, I wasn't feeling so smart. I had a feeling my day / night sensor might be at fault.

I read a bit about day / night sensors and learned that there are different types.  I had one that is wired in-line with the light.  With only two wires, it doesn't ever completely shut off the power for the light.  In fact, I noticed that the LED bulb would still glow slightly during the day time (my first clue).  Even when fully on, the bulb would buzz audibly (my second clue).  I suppose incandescent bulbs can take the abuse caused by the sensor, but an LED bulb apparently can't.

Note that they do sell dimmer compatible LED bulbs, but they are more expensive (and might not even help in this case).  The problem was the sensor, not the bulb.  Here is a picture of my old sensor:

What I needed was a day / night sensor that fully switched off the light (e.g. with a mechanical relay).  I found these sensors by searching for "fluorescent compatible dusk/dawn sensor" (they weren't otherwise easy to find).  This sensor should work for any type of bulb (both CFL and LED alike).  Since it was cheap (and easy) enough, I simply replaced by old sensor.

Of course, I could have also simply disabled the old sensor.  LED bulbs use so little electricity, this would only be a minor waste and cost.  With the new sensor I'll save money mostly by making the bulbs (hopefully) last longer.

Besides, after destroying two bulbs, it was now a matter of pride that I make it work!

The new sensor was a direct physical replacement for my old one, I just needed to enlarge the sensor hole a bit and rewire the circuit per the included instructions.  Note the three wires below:

I even moved the sensor to a "smarter" position on top of the fixture so that the light doesn't cause it to switch off / on accidentally:

Here is my new LED porch light on with an (incandescent) outdoor column light in the foreground for comparison.  Note that the color of the porch light is a bit whiter, but still acceptable (in my opinion).

Project #2:  Low voltage (12VAC) landscape lighting

With the porch light done, I thought I'd tackle the (hopefully easier) outdoor lighting for my housing complex.

We have a 12V AC (low voltage) system with 18 lights in total.  10 of the lights are 25 Watt column lights and the remaining 8 are 16 Watt stake lights.   This is a total of 378 Watts!

Even with our timer / light sensor, they are on about 8 hours a day and consume about 3 Kilowatt hours per day (very wasteful in hindsight!).

In order to replace these lights, I found a low voltage LED bulb that:

• Had a wedge base (compatible with our stake lights)
• Worked on 12V AC (some bulbs are DC only)
• Radiated light in all directions (just like the old bulbs)
• Had a warm color temperature (like my porch light)
• Long life (50,000 hours)
• Low power (2 Watts)
• Produced an equivalent amount of light (to the old bulbs)
• Cheap enough to make replacing 18 bulbs economical

The above link is a reference.  I actually found the bulbs cheaper elsewhere at about $5 per bulb here.

After installing these bulbs the actual measured total power (using my handy Kill-O-Watt meter) dropped from 370 to under 40 Watts (a huge difference)!  I figure this is going to save $75 per year.  And, as a bonus, they are in fact brighter than the bulbs that they replaced!

As far as color is concerned, they are definitely "whiter", but since I got the "warm white" version, they aren't bluish - white like many outdoor LED lights.  They also now perfectly match my porch light.

Installation pictures

Note: For the outdoor lights, I had two types of fixtures to deal with (column lights and stake lights).  Both types of lights are low voltage (12 V AC).

Column lights

Note that our column lights are a bit unusual in that they use a regular (medium base) 120 Volt light fixture.  This was a pain because I had to find low voltage bulbs that screwed into a medium base (shown above).

While it is possible to also find low voltage LED bulbs with a medium base, they are more expensive and you don't have as many choices (like wattage and light color).  I thought it would be better if I could find an adapter which would enable me to use the same bulbs as I do for our stake lights.

In case anyone is interested, I bought the adapters (shown installed above with the LED bulb) from Harrington Lights (product id R3-MED-T5-WEDGE).

Stake lights

Note that the replacement LED bulbs are a bit taller than the incandescent bulbs that they replaced.  Fortunately, they still fit in the stake lights (but it was a much tighter fit as you can see below).