Slashdot Mirror
Sunlight in a Tube
Elitist_Phoenix writes "Scientists are developing a technology to save energy by transmitting sunlight into buildings through tubes. Indoor electric lighting is the largest consumer of electricity in commercial buildings. Their new system. called hybrid solar lighting, would reduce this energy usage with fixtures that supplement or completely replace electric light with sunlight, at times when its available. The system is called hybrid solar lighting (Google)."
From the article:
In the system, a rooftop collector concentrates and sends sunlight through optical fibers, tubes made of special, high-purity material that transmit light by reflecting it down their inner walls.
Environmental Building News, Volume 8, Number 10 - October 1999
Imagine a device that sits on the roof of a building and focuses sunlight into cables the size of electrical wire. These cables are run through walls and ceiling plenums into light fixtures that beam natural, full spectrum daylight deep into a building's interior."
it's called Hybrid Lighting or Daylighting. Been around for a looooooong time.
my karma will be here long after I'm gone
Actually, this is different than simple redirected light. Check out this link for more information. Basically, it runs the sunlight through fiberoptic cables to light fixtures that work much like our current light bulbs. These means that you won't have to have serious architectural redesigns of buildings to get the same effect. It also will generate electricity that can be used for other applications (powering computers?). It is basically a hybrid approach to lighting.
I believe in de-evolution. God made the world perfect, man fell, and its been going downhill ever since!
All of you who are immediately attacking the idea saying "haven't we done this before" are missing the point. This is not just redirected light. It is transporting the light through fiberoptic cables and transferring that energy through regular light fixtures. This would allow solar power to light internal rooms that don't have windows. It also will generate electricity for other internal applications beyond light.
This technology would allow businesses to retrofit their buildings with solar light without having to do heavy remodelling to add skylights (the old way of doing it). This can be especially difficult for multi-floored buildings with internal rooms. Please read about the technology before immediately dismissing it as "nothing new".
I believe in de-evolution. God made the world perfect, man fell, and its been going downhill ever since!
Not the same thing at all. Your link requires a big tube, which is impractical in office buildings. This uses fiber optics, or really little tubes.
"Indoor electric lighting is the largest consumer of electricity in commercial buildings."
Where is this true? I worked as a stationary engineer in commercial buildings for years. HVAC was, I thought, always the biggest consumption of power. Of course, I'm in Las Vegas where in the summer the power bills are 4 times in the summer what they are in the fall.
Sailing ships used compact prisms to convey light to interior rooms without the need for large areas of fragile glass.
And 3M had a material called SOLF, a vaguely Scotchlite-like material with tiny prism that could be made into tubes with highly efficient nearly-total internal reflection, that could carry light in, say, six-inch pipes over distances of many yards with negligible loss. Not terribly expensive, either.
"How to Do Nothing," kids activities, back in print!
The prevailing opinion here seems to be that this is a stupid story, because light pipes are old news. Two people have even been moderated up to +5 for posting links to light pipe vendors.
Light pipes are NOT the story here. Hybrid lighting is a NEW lighting system which separates the visible and IR components of sunlight, directing the visible components to room lighting and the IR components to thermo-voltaic generator, which stores electrical energy to light the room after the sun has gone down. Ordinary light pipes do not do that.
From the U.S. Department of Energy Solar FAQ:
Q:How does a hybrid solar lighting (HSL) system work?
A:Imagine being able to light your home or office most of the day, and on most days, with sunlight, but not the kind that comes through the windows. That's what hybrid solar lighting (or HSL) systems are being developed to do. Prototype HSL systems are made up of roof-mounted concentrators that collect and separate the visible and infrared portions of sunlight. The visible portion of the light is distributed through large-diameter optical fibers to hybrid luminaires. (Hybrid luminaires are lighting fixtures that contain both electric lamps and fiber optics to distribute sunlight directly.) Unlike conventional electric lamps, the solar component of HSL produces little heat.
The remaining "invisible" energy in the sunlight, mostly infrared radiation, is directed to a concentrating thermo-photovoltaic (solar) cell that very efficiently converts infrared radiation into electricity. The resulting electric power can be directed to other uses in a building. When sunlight is plentiful, the fiber optics in the luminaires can provide all or most of the light needed in a particular area. But when there is little or no sunlight, sensor-controlled electric lamps turn on to maintain the desired illumination level.
Independent cost and performance models suggest the overall affordability of solar energy could be doubled or tripled by using this new hybrid approach. The multidisciplinary R&D effort involved in developing HSL includes several industrial and university partners. Other Resources:
Ceci n'est pas une signature.
William Wheeler invented a system to light up buildings with light pipes in 1880.
These Existing Solar Tube of systems are great for Houses, but they lose a lot of light per metre so there value in using them to pipe light to the lower floor of even a two storey house is limited. also they lack flexibility as the collector needs to basically be above the area the light is wanted.
The System from the article is not that new either, the basic idea has been around for a while. Although the cost of the Optic Fibre (vs. under priced electric power) has always been a factor limiting the deployment of systems such as the one in the article.
The Advantage of and Optic Fibre System is that optic fibre can carry light at much lower loss levels per metre. This means a fibre system is good for multi-storey work, like commercial office buildings.
Where we are trying to push the light 7-8m(21-26ft) horizontally into the building. Vertically allow say +3m(10-12ft) per floor. In an 8 storey building you need to be able to push light around 40m and around many corners.
An the advantages of using natural light are more than just the power saving. Using Natural light can vastly improve the health of the building. Enclosed areas like fire stairs, toilets, plant rooms will all stay cleaner if lit with natural light.
"Call us when the New age is old enough to drink" Beck