原创 Green Home Lighting

Worldwide, there has been a push to use CFL lighting instead of incandescent lighting. However, with CFL lighting, we will have to think of how the bulbs would be disposed off after use. Heavy metals like mercury, xenon, sodium, etc. should not contaminate the water source.
The next best alternative is LED lighting. Just like the CFLs, LED lighting needs specific powering schemes since they cannot use AC source that is routed around the house. Just to compare, 60W Incandescent is equivalent to about 14 Watts CFL and is equivalent to about 6W of white LED lighting. Though in the beginning the initial cost of ownership is high, the long term savings completely offset the upfront investment.
Please check the link below for a good comparison of different kinds of lighting.
http://www.scribd.com/doc/3222967/Incandescent-vs-CFL-vs-LED-Savings
I propose two different schemes for use of LED lighting at home:

1. Centralised AC-DC power supply: The total power consumption of the home is calculated and then multiple DC secondary rails are routed around the home. The DC wiring has to be done at the time of construction of the house. If the current AC wiring is used, one may have a larger drop than needed and hence the power loss. Some local power conversion is needed in order to provide dimming and motion sensor based ON/OFF control. This scheme however lends itself well to having either a solar or battery back up for lighting.
   
2. Point of Load AC-DC: Discontinuous mode flyback at the point of load. This offers one single complete solution at the point of use. AC-DC conversion, motion sensor interface plus Dimming option can all be in one single unit.

Both have their advantages and disadvantages. First one has to be thought off at the beginning of any construction but the second one can be implemented as an afterthought.
Any thoughts?