Electrical power consumption in buildings may be reduced considerably by more efficient use of sunlight for indoor lighting. A stack of luminescent solar concentrator sheets has been developed, which utilises three different coloured fluorescent dyes to produce a concentrated near-white light source to be coupled into flexible polymer sheets and transported up to 10m. Thus in clear sky conditions a remote room with neither walls nor roof in direct contact with the sun, can be illuminated by over 1000 lm of natural light with a luminous efficacy of over 300 lm/W, regardless of the sun's position. (C) 2004 Elsevier B.V. All rights reserved.