Night lights powered by hot radiators

The HeatLight is the brainchild of IT expert Robert Johnson, who has co-founded a company to exploit the idea with mechanical engineer, Michael Reid. The device uses a thermoelectric Peltier generator to charge up a battery, which powers LEDs when a passive infrared sensor detects somebody walking past and absence of light. Reid says: "A Peltier generator has only 12% efficiency relative to the Carnot Cycle, but that efficiency is not the important factor. The importance is to have a free source of energy." The first target market is the medical sector, which will involve attaching the units to hospital radiators. Reid explains: "This is particularly beneficial in offices where the main lighting is via fluorescent strips, as these require significant energy to fire up, and turning them on and off can reduce life expectancy. A system of night lights can provide security and safety and cut costs. Within a domestic setting, the HeatLight could clip onto a radiator in a child's room, hallway or bathroom and provide a reassuring safety light at night or during a power cut, for no additional cost. Other applications would be outdoor signage, safety information and emergency lighting when a generator fails." Full production of the commercial units (shown) is expected to begin in about a year.