The near future is solar energy and - perhaps in a far future - the fusion of light nuclei. Energy storage ist the keystone of the solar powered near future of energy supply.

A lot of articles were written about efficiency of light sources and there power consumption. But what are the essentials of light? Yes, it's quality in terms of rendering or spatial distribution. And it's quantity well choosen for different tasks.

Ever thought to reduce the energy demand by a thoughtful optimization of your house or flat? This will reduce future costs and the energy demand. O.k., you are right. You have to invest some money. But this is meant by "thoughtful".

Check the balance between investment and benefit for different measures and different options to find the optimum package!

The big question is: Which light source provides the higher light output per watt of electricity? Many believe that flourescent lamps have a 5 times higher light output per watt. That is true with standard light bulbs. But it is not true for modern state of the art light bulbs.