TreeHugger has shown a number of different schemes for transmitting natural sunlight into interior spaces. There are real benefits; sunlight is free, and our bodies are tuned to it, relying on the changes in colour throughout the day to regulate our body clocks. Sunportal is a new system developed in South Korea that claims to be better than the others.
Our patented SUNPORTAL technology allows the best natural daylight to reach and illuminate any indoor environment, including deep plan building spaces that no other conventional daylighting systems can deliver.
It actively captures and effectively transports maximum sunlight from a heliostat with a unique parabolic dish concentrator to a luminaire via a series of special optical relay lenses, providing the highest transmission rates over any long distances and in any directions.
I wonder whether this makes any sense. You have a big heliostat shining on one end, a big expensive glass pipe, a series of lenses and diffusers along the way yet the light never seems to get dimmer as you get further from the source. It has a backup LED lighting system for when the sun doesn't shine; wouldn't it be more sensible just to put solar panels on the roof, pipe the electricity instead of the light, and just run the LEDs?
The embodied energy of making all that glass piping will take a hundred years to pay back in energy savings. It's all too much.