is what it's called
www.nyseg.com/nysegweb/main.nsf/doc/prodflood

would cover both spots and floods, and (I assume) the remaining context would cover the fact that less lighting is actually being wasted, lighting up the sky rather than the target.

schlicht und einfach.
Siehe auch eurodicautom...wo Strahler = emitter (radionuclear) radiator (heating) or lamp (lighting)

... is what I would say here. I think David and Tina are on the right track in being general. Here's how I understand the sentence: They managed to decrease energy consumption 20% (to 80% of its previous value), even though they had 7 times the number of (individual) lights.

Normally I would say spot light but I think they're being very general here, not specifying whether spot, flood, or whatever.

My problem with "illumination" is, how do you work the 7-fach in? I do think they're talking about individual lighting units, not the total number of lumens achieved, which makes "ilumination" hard to quantize.

"Lamps" sounds too German to me; makes me think of reading lamps like this
http://www.sgoosie.com/images/lamp-2.jpg

"Strahler" may mean any type of lamp, there are no more definite indication in this context.

The whole sentence:

While illuminating the object (name of monument) using these lamps (or way of illumination) the energy balance could be lowered in 80% including 7-times lowering of energy balance in lamps theirself.

I suppose, the energy consumption is compared with the case of using other lamps or other way of illumination.

We obtain 7-times win in a lamp itself and 80% win in total.

I think Strahler refers to a lamp that illuminates a defined circular area - a spot light.

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Note added at 8 hrs 13 mins (2003-07-01 20:20:17 GMT)
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I\'m withdrawing my answer. This is wrong, e-rich got it right.