Paving slabs that harvest kinetic energy from footsteps can generate electricity. When walked on, the slabs glow to indicate energy generation to users. Only 5% of the energy is used for this display; the rest is stored in batteries. The slabs convert footstep vibrations into electricity using magnets and coils. While an individual generates little power, many people in busy areas like metro stations can generate significant amounts. The energy can be used to power lights and small appliances. Testing in London has been successful and the technology may be implemented in other busy areas around the world.