Výmluvné jsou ale i~úryvky z~archivu DarkSky-listu o~nápravě osvětlovací soustavy v~Calgary:
Calgary's decision is unique among recent light-pollution initiatives. It calls for the changing of all residential street lighting immediately; most cities replace their fixtures gradually, as the old ones malfunction. But what the city spends now it will recover later -- government officials project that each year Calgary can expect to save $2.1 million Canadian ($1.4 million US) in electricity. Even if energy prices drop to their previous levels, it will take only 6.5 years to recoup the project's $7.8 million ($5.2 million US) cost.
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You note that Calgary, Alberta, has embarked on a~program to convert all streetlights to fully shielded types and simultaneously reduce wattage by half. A~memorandum prepared by the Calgary Police Service reached this conclusion: "It may have been argued that common sense dictated that greater lighting translated into greater safety. However, we now know this is not true."