Well, the astronomy guys would really like it if you use low-pressure sodium lights, because they can filter out the sodium line. Anything resembling a white light pretty much blinds telescopes by lighting up the night sky.
I don't know if that's the sort of "innovation" you were looking for.
The minimum/maximum distance is calculated in relation to the height of the poles and fixtures. You need to define one of the variables in order to calculate the other, and all of this information should be based on the parametric specifications of the specific fixture.
Most lighting manufacturers provide this information for each fixture they have on the market for the design questions you are putting fourth in this forum. Often this information is available on the manufacturers web site, in the form of a .pdf file that can be downloaded. If the job is big enough, the manufacturers will usually be happy to assist you in design of your installation.
250W Metal Halides, in my experience, are usually coupled with 15'-20' poles. Commonly 20'.
A 23W CFL "lollipop", or spherical type globe fixture, is rarely placed above 10', as the low light output would be useless above this height (the fixture would glow, but not project useable path lighting).
Once you figure out how many fixtures will be needed and the total length of the run, total amperage, etc, you can calculate wire size, power requirements, number of circuits, control options, etc.
Re: Streetlighting Innovations?
#174158 01/28/0801:36 AM01/28/0801:36 AM
I don't have any links, but I recently read an article about the town of Holly, Colorado USA that was wiped out last year by a tornado. Town being rebuilt, and the power supplier XCEL is donating LED street lights. XCEL dosn't even supply power to this area, yet they are helping out.
A google search should turn up new ideas for streetlighting.