Using the same principle as a water wheel, the generator uses the weight of the rock coming off a conveyor belt to produce electricity.
The project is the first to be introduced by Hanson’s Renewable Energy Group and is part of the company’s long term commitment to reducing carbon emissions and energy use.
Martin Crow, head of environment and sustainability, said: “Recouping energy in this way is a great example of thinking outside of the box. By adapting the conveyor system we are now able to recover some of the energy needed to run it.
“It is early days, but if it’s successful it’s something that could be introduced at other sites. We are committed to investing in projects that will cut energy use or generate power from renewable sources.”