Hull based Ciralight is wringing a bit more from the UK’s overcast skies now it is sole supplier of the US developed ‘Active Skylight’, which tracks the sun’s  movement to optimise internal lighting levels for large spaces, reducing the need for electric lighting. The skylight is housed in a rooftop plastic dome and uses a GPS controller and a microprocessor to calculate and track the position of the sun. It reflects sunlight via a mirror array down into the space via a highly reflective integral light well. Called the ‘Suntracker’ in the US, the firm sadly felt that low UK expectations of the weather meant that name could be successfully marketed here. Instead, it hopes the energy-saving potential of its revolving rooflight will turn heads and turn off lights.