Passive Emergency Lighting
by TreeHugger on 04. 7.05
A New Zealand company, ecoglo, is by their own account becoming the world leader in passive emergency lighting. The patented ecoglo technology bakes a photoluminescent material into an aluminum extrusion. The product requires no energy to run, thus it can work in a complete power outage, and can be used to replace emergency lighting. They company thinks that their line of products can also significantly reduce construction costs, and they go the extra mile to make sure their products apply to legal codes around the world. Ecoglo has found a home in stadiums, theaters and other public arenas down under. *Their product is non-radioactive and non-toxic, and responds to both indoor and outdoor (sun) lighting. I think a good at home application might be to put it on the steps down to my grandmother's cellar. (*Special thanks to the comments section for making sure I'm on my toes) ::ecoglo [by T. McGee]
Products such as these are already in use in the United States and have been for quite sometime. Some typical examples are the emergency exit lighting and signage in parking garages. One typical complaint is that they do produce trace amounts of radiation. Not to bad these days but at their inseption, you didn't want to wait around if one happened to fall from its mounting.
Is this powered by baked in tritium? If so, what makes it "eco" glo? If its not tritium, might be cool to mix it in architecturally with some LiTraCon translucent concrete.
To Answer Your Questions::
The material appears to be based on a photo-luminescent 'pigment' (which is generally an organic molecule that absorbs a specific spectrum of light). It is 'powered' by light from the sun, fluorescent lamps, or metal halide lamps. The pigment 'stores' the electrons in an excited state as long as there is more energy input from surrounding light. As soon as the light is gone, the pigments continue a controlled release of their excited state down to their base state, in the process releasing photons at a certain wavelength of light...in this case probably around 510 nm (for Green light).
As for the radiation, this product is non-radioactive, and environmentally safe. In fact on their website they say:
"The pigment is non-radioactive, non-toxic, and responds to both solar and artificial light sources"
Also in the development of the product they were very concerned about the ecological footprint....and say:
"Environmental standards Eco-rating principles were developed taking into account the desirability of principles such as zero greenhouse effect, use of solar energy, recycling, use of biodegradable materials and durable materials."
Also interesting:
(http://www.ecoglo.com/index.cfm/Demonstration/Interactive_Demo)
So indeed this is not your fathers emergency (radioactive) exit lighting.
This seems like a "natural" application for school buses. The inside roof support beams or panels which can be added accoustics. In either case it might provide enough ambient light for a driver facing in the other direction to see some more of what the 70+ elementary students behind her are doing. Video might be easier too in the wee hours or those long after school athletic activity trips since sorm of our districts students have hour+ trips one-way daily.