Mpfana Manu is a mechatronic engineer who's working in green energy electronics products.
There was a time when fluorescent lambs were the new miracle in the world but now they're getting sprinted out in much of their applications by LED lambs.
In this article, you're going to learn various aspects of fluorescent lights and how they relate to different types of solar power systems.
You're going to learn how fluorescent lights work, how they die and how fit they're to be solar powered. Also, we'll get into which applications you should consider replacing them with LED lights and reasons why you should do so. Enough introductions already, lets dive in.
How fluorescent lights work
Almost all fluorescent lights are in the form of a tube that is often white in colour. The tubes come in different shapes too (circular, rectangular, straight, etc).
The tube will be having an electrode at each end of the tube. The tube will be containing mercury vapour and an inert gas, usually argon.
The wall of the the glass tube will be coated with a phosphor. In case you have no idea what a phosphor is, it is a substance that glows or emit light when electromagnetic radiation falls on it.
In this case, the radiation is ultraviolet light. There are many phosphors, they differ in the color of light they emit and the amount of ultraviolet radiation they need to emit the light.
So for a fluorescent lamb to light up, an external circuit sets a potential difference between the electrodes in the tube. There's a certain voltage at which an arc forms between the electrodes.
This arc energizes the electrons of the vapour in the tube which then emit ultraviolet radiation. This radiation is then absorbed by the phosphor at the walls of the tube and light is emitted from the walls. And that is how that angelic light is produced.
What causes fluorescent lights to fail/die?
If you've ever used a fluorescent light before, you know it can just suddenly stop lighting. What causes it to fail may be of use. In some cases, the lifespan of a fluorescent light may be extended if you know how to treat it and the places it is not supposed to be installed.
The average lifespan of a fluorescent light is 12,000hours to 20,000hours at 3 burning hours per start. Here are common causes of premature light failure and how you can counter them to protect your fluorescent lights so that it lasts for its standard lifespan.
The performance of these lights is affected by radio waves, especially from an AM radio antenna. The waves stimulate radio radiation to be produced in the light and the light may start glitching in phase with the radio waves. Just keep your lights from any radio aerial around. Glitching reduces the lifespan of the lamp.
Fluorescent lights perform at their best at a temperature range of 38-49°C, which is the operating temperature under ambient room temperatures of 21-27°C.
The efficiency drops steadily as temperature rises but it drops heavily as temperature decreases. So these lights are not fit to be installed outdoors, especially in areas with cold nights and hot days. The unsteady efficiency alters the lumen of the light and this also may cause premature failure.
Most fluorescent lights are not designed for dimming applications. However, there are specialized fluorescent lights with specialized ballasts that can be used for dimming applications but that would need you to get a light electrician to buy your lights for you. If the common ones are used, they're likely to start humming during operation and then finally fail prematurely.
Which solar power systems are best for fluorescent lights?
The design of fluorescent lights make them perform better with AC current than with DC current. AC current is supplied more effectively by grid-tied solar power systems.
Current that is drawn from the junction box of solar panels or from solar charged batteries is DC current, therefore it's not advisable to directly connect fluorescent lights to the panels or batteries.
However, a stand-alone solar power system can support fluorescent lights if the DC current generated or drawn from batteries is converted to AC current. In solar power , DC is converted to AC by means of an inverter.
The only downside of inverters is that they increase the resistance of the solar power system, making it less efficient.
So the best solar power system for fluorescent lighting is the grid-tied system. Any stand-alone system would need an inverter. Most modern stand-alone kits for home use have inverters but if yours doesn't, consider installing it if you're powering fluorescent lights.
Solar lighting applications you should consider replacing fluorescent lights
Outdoor solar lighting
As mentioned before, fluorescent lights are not very efficient in alternating temperatures so it would be better if your outdoor solar lights are LED lights. LEDs are not affected by alternating temperatures as much as fluorescents.
And also, LEDs consume less power yet delivering the same illumination. If less power is consumed from your solar system, your battery banks will last longer before getting exhausted.
Pavement/street solar lighting
Pavement lighting includes the overhead lights and embedded lights across/along your home pavements and roads. Modern solar lighting kits for pavements come with proximity sensors which give the lighting system an ability to serve you when you need it only.
Have you ever walked into those kind of street lights that are normally off but switch on when you walk close to them? Yes, that is the lighting system I'm talking about.
Fluorescent lights used to be employed with these systems (in garages, fields, etc) but now there are other more energy-effective and more lasting alternatives like LEDS. When such a lighting system is solar powered, its performance is mainly judged by how long it lasts.
The lifespan of fluorescents is longer when it's switched on for longer hours but it significantly drops when it keeps getting switched on and off more frequently. LED lights are not affected by that which makes them a better substitute to replace fluorescent lights.
Mpfana Manu (author) from Harare on January 18, 2020:
Patrick Kamau from Nairobi, Kenya on January 17, 2020:
Thanks for sharing. At least now I know why I have to keep buying bulbs. I have also noted that faulty bulb holders destroy bulbs more often.