Question about Solar LED lights

[emarie15]

I have been doing a lot of research about LED lights and Solar Panels and I am just not sold yet that Solar is worth the price of initial installation. My question is, Considering LED lights are great alternatives to previous light bulbs and they use almost half the energy how do they compare to each other? I mean is it really worth the expense of solar if I can just switch to all LED lights? Ideally I want to do both but my wallet is restricting me. I recently purchased my LED lights from Inpired LED and they work great, but part of me is still guilty for not trying harder to get some solar into my life.

What do you think?

[Naptown]

Considering lighting is a very small portion of your total electric consumption annually and LED's are not all that efficient for general lighting (CFL's are better)
probably not. It is however a first step. Do everything you can do to reduce your use. Have an energy audit done and follow their recommendations. Then think about solar.

[inetdog]

Considering lighting is a very small portion of your total electric consumption annually and LED's are not all that efficient for general lighting (CFL's are better)
probably not. It is however a first step. Do everything you can do to reduce your use. Have an energy audit done and follow their recommendations. Then think about solar.

I respectfully disagree with you there, given the newest crop of LED lamps. They have good color temperature, are easily dimmable, and are being made to fit more and more fixture types. I do expect it to be a very long time before they make either LED or CFL replacements for oven lights.

The prices are still on the high side, but other than cheap early designs like the ones Costco featured and then recalled a month later, I have not yet seen an LED lamp fail early, while most CFLs have gone well below their rated life for me. And their slow ramp up of light output is just not good where safety or security require immediate full intensity.

Finally, if you will be in a position to use 12 volt distribution wiring, LEDs have the advantage hands down, IMHO.

But at the bottom line, they are not the big power consumers except for some off-grid low tech environments.

BTW, they use a lot less than 1/2 of the power of incandescent, even halogen. And the reduced heat does also reduce A/C loading. But they are not better in luminous efficiency (light per watt) than CFLs yet.

[Sunking]

I respectfully disagree with you there, given the newest crop of LED lamps. They have good color temperature, are easily dimmable, and are being made to fit more and more fixture types. I do expect it to be a very long time before they make either LED or CFL replacements for oven lights.

I agree in part with you, but the fact remains once you take the total power consumed by both the driver and LED, narrow beam width vs Lumen output are not a whole lot better than plain ole Edison incandescent bulbs. Today the T5 is king in efficiency and color temp at around 105 L/W for indoor lighting. LED's are decent in specialized applications like landscape, flashlights, signal, display, accent, and task lighting but still have a long way to go.

If you have some late information I would like to see it.

[inetdog]

I agree in part with you, but the fact remains once you take the total power consumed by both the driver and LED, narrow beam width vs Lumen output are not a whole lot better than plain ole Edison incandescent bulbs. Today the T5 is king in efficiency and color temp at around 105 L/W for indoor lighting. LED's are decent in specialized applications like landscape, flashlights, signal, display, accent, and task lighting but still have a long way to go.

If you have some late information I would like to see it.

T5s I have no objection to, and I respect their efficiency. But they are not used in any CFLs that I have seen, and that was what you recommended.

The efficiency figures for LED lamps (as opposed to bare LEDs) are typically calculated to include the driver losses, just as they are for CFLs. Use of phosphors in conjunction with short wavelength LEDs helps both the beamwidth and the color accuracy problems, and allows the LEDs themselves to be chosen for highest conversion efficiency rather than best color rendering.

I am using some 40-watt-type-A-replacement LEDs which use 8 watts from 120 volts, 60 Hz. AC, deliver 430 initial lumens, have a "rated" life expectancy of 46 years at 3 hours per day (yes, I have trouble believing that last one too!) and color temperature of 3000K. I would prefer a bit higher color temperature for task lighting, but for general purpose interior they are just fine. (My favorite T12 lamps are Spec35 but they are used in such small volume that they are priced too high for me now.)

The translucent portion of the lamp is a little more than one hemisphere, and when looking at it from within that angle, it is indistinguishable from a 40 watt incandescent, with the exception that it has no logo visible at the center. The whole hemisphere looks uniformly illuminated, with a diffuse hot spot in the center from all (limited) angles, just as you see when looking at a Soft White incandescent.

I have high hopes for these lamps (at $9.00 each) and will keep you advised over the next 30 years how they work out.

Because of the weight of the conical driver section at the back where the base is attached, and the lack of light output in that direction, they are not suitable for base down use in table lamps. But there are a lot of fixtures, including pendants, where they work perfectly well.

They are instant-on and their dimming characteristics are a lot closer matched to those of an Edison bulb than any dimmable CFL (or for that matter T5 fixture) that I have ever seen. They work better with an ordinary residential dimmer than a fluorescent of any kind that I have seen with a dimming ballast using a solid state dimmer rated specifically for fluorescent use. With their use of phosphors, the strobe effect at 120 Hz. is reduced.

I am test using them for general lighting in ceiling fixtures, bowl reflector type torchieres, and in track lights designed for use with an A type lamp.

We shall see.

[Sunking]

I am using some 40-watt-type-A-replacement LEDs which use 8 watts from 120 volts, 60 Hz. AC, deliver 430 initial lumens,

Well that is what I was referring to about that their efficiency was not a lot to brag about @ 53 l/w. That is just about equal or slightly less than quality CFL, and 1/2 of T5.

I do a lot of lightning work and have been keeping my eye on LED's for some years know waiting for them to be able to compete with traditional florescent lighting. I am still waiting.

[inetdog]

Well that is what I was referring to about that their efficiency was not a lot to brag about @ 53 l/w. That is just about equal or slightly less than quality CFL, and 1/2 of T5.

I do a lot of lightning work and have been keeping my eye on LED's for some years know waiting for them to be able to compete with traditional florescent lighting. I am still waiting.

But even 53 lumens/watt is lot better than incandescent! And I am limited, for now, to using existing fixtures, so traditional fluorescent is not an option. Even quality CFLs irritate me severely for some uses. A balanced approach, using each type where it is at its best, is certainly the way to go, especially if designing from scratch. I think we agree on all of these points, and our differences are primarily in our decision criteria and the bias of our sweeping generalizations.

[Sunking]

But even 53 lumens/watt is lot better than incandescent!

I agree.

[IlzeGreene]

Do Solar Lights make sense?

The answer to your question is "it depends." You certainly don't have to feel guilty if you didn't buy it!

It's very unlikely that energy savings alone will off-set the cost of solar lights, much less actually save you money.

The payback for solar powered lighting comes mostly from avoided installation costs. No switchgear, trenching and conduit are required, so in commercial applications, where the wiring infrastructure isn't in place or isn't available, a solar powered street or parking lot lighting project can cost LESS than one with conventional grid-tied lighting. Once it's in place you will enjoy having no electric bill and you will have uninterrupted lighting during power failures!

If you already have easy access to power, it probably doesn't make sense.

That's not to say that we, as a country, don't use more than our share of energy for outdoor lighting. I recently read that electric consumption of outdoor lighting in the U.S. totaled about 200 TWh per year, that's about 150 Million Metric Tons of CO2 emissions per year.

So you can feel proud of your conversion to LED!