When the sun goes down, the hydrogen powers a fuel cell that runs your home.

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Today, when the sun goes down in Africa, over 150 million homes will not turn on the lights.

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This fortress becomes crucial when the sun goes down and the undead rise.

FORBES: Connect

Since San Juan is largely without power, when the sun goes down darkness prevails, pierced only by the occasional flicker of candlelight.

BBC: Journey to Argentina's forgotten territory

It's starting to wonder why you so remind me, why you so remind me, of the same (unintelligible) when the sun goes down.

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When the sun goes down, crossing the line between the City of Light and the City of Darkness is eerie, almost post-apocalyptic: moving within minutes from the bright lights of Times Square to the narrow unlit streets of the Financial District with the looming outlines of skyscrapers towering overhead.

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When the device is aligned so that its pits are pointing straight at the sun, most of the incident radiation goes down them to their bottoms.

ECONOMIST: Solar power

From sandy riverbed campsites you can watch flocks of colourful parrots as the sun goes down, and the night becomes even more eerie when dingoes fill the darkness with their howls.

BBC: Walking through Australia��s pure desert heart