Let's say that we have a space station orbiting the Earth around the equator at a speed of 360 degrees per 24 hours, always being roughly on the line between the centers of the Earth and the sun. From the point of view of those on the station, the Earth would always look fully illuminated. (In case it makes a huge difference, let's say that it orbits at the same height as the ISS.)
Now, let's say that the half of the station facing the Earth is a large, dome-shaped window, allowing the entire planet (well, the half of it facing the station) to be seen at the same time. It doesn't have any windows facing the sun, however.
If the power were to go out on the station (thus disabling all artificial illumination and leaving the light reflected off of the Earth the only source of light), how well-illuminated would the station be? Would there be enough light to find one's way around the station, perhaps even doing some repair work?
Here on Earth, we can still see somewhat with a full moon as our only source of light. Now, the Earth doesn't seem to reflect quite as much light, but it's several orders of magnitude closer to the station than the Earth is to the moon, so the question is whether or not it's enough to be a passable source of light.