For sure you know the scene. You are stroll along on a plaza or promenade that shines and glitters with amazing colorful effect. Just beautiful! havent’t you asked yourself the question “who is paying the electricity bills for all this great lighting effects?”
Well, truth is – nobody – if the architects have been smart and environmental conscious…
Nobody paying for the electricity? How?
These lighting effects do not need electrical power, do not need cabling – they are powered by sunlight! They are Solar LED ground lights.
For sure you know about all the advantages of LED and LED lighting; low energy consumption, small size, long life…and for sure you have heard about Solar power. So why not combine these things into one beautiful looking Lighting fixture?
This is exactly what has been done with Solar LED ground lights.
What are Solar LED ground lights and how do they work?
With todays innovation solar cells become smaller and are able to deliver more power in smaller sizes. The solar cells for example deliver 100mA and this delivered energy from the sun is stored in in Ni-MH rechargeable batteries with up to 1800mAh capacity.
Alternatively can so called “super capacitors” be used to store the energy – the solar cell charges them and the store the energy like a battery – except they can hold more energy and their lifetime is much longer than the life time of a rechargeable battery. We come to this a a little later.
Back to the LED solar ground light.
After 1 sunny day their batteries are fully charged. The sun goes down and a built in light sensor switches the Solar LED ground light on. With 1 days charge these lights will run for about 12 hours, if the battery fully charged the can run for 3 nights!
Once daylight comes back, the light sensor switches the solar LED ground light off and the charging cycle starts again. Clever huh?
But how long will the solar LED ground lights last?
That depends besides other factors mainly on the type of battery used or the method how the energy is stored.
Nowadays available Ni-MH batteries go through 1,000 charging cycles if done right – this is almost 3 years. Using Supercaps is the even better (although a bit more expensive) option. Due its technology they offer Long life, with little degradation over hundreds of thousands of charge cycles. Of course nothing lasts forever but a lifetime of about 8 years is not unusal.
And this is what we have here – A light powered by the sun, switched on and off automatically with a lifetime of up to 8 years. No wiring, no maintenance but night after night a great and impressive looking outdoor lighting scene.
If this is not environmental friendly – then what is?