Science and technology.Photoelectric cells.To dye for.A new type of cell may bring "solar" energy indoors.THE phrase "indoor solar power" sounds like an oxymoron. But there is growing interest in the idea of using photoelectric cells to run gadgets as well as power grids-and doing so even when those gadgets are inside buildings.Much of the light these cells used would, of necessity, come from incandescent bulbs, fluorescent tubes and light-emitting diodes (LEDs) rather than through the window from the sun.But if the right sorts of cells were available this could be cheaper than constantly replacing the batteries that currently power electronic gizmos.On April 8th G24 Innovations, a firm based in Wales, announced that it may have come up with just such a cell.The latest version of its special, dye-based photoelectric devices has set a new record for the conversion of light from bulbs into electricity: an efficiency of 26%, compared with the 15% which previous ones can manage.That lifts dye-based cells to the point where they might be widely deployable for indoor power.Dye-based cells are similar to the silicon-based variety found on rooftops around the world in that both rely on a semiconductor to assist the conversion of luminous energy into the electrical sort.