Renewable Energy on Demand

Engineers have put forward a conceptual design for renewable energy storage that would be capable of powering a small city by delivering energy back to the grid on demand, 24 hours a day. Dubbed “Sun in a Box,” the system would store heat generated by excess electricity from renewable sources in large tanks of white hot, molten silicon. The light from the glowing metal could then be converted back into electricity using specialized solar cells.

The proposed system would be composed of a large, heavily insulated graphite tank filled with liquid silicon at a temperature of about 3,500 degrees Fahrenheit. This tank would be connected to a second, hotter tank via a bank of tubes. Heating elements would capture the energy from a renewable source (such as solar or wind power) and heat the cooler silicon as it passes on to the hot tank, where the energy would be stored at a temperature of about 4,300 degrees Fahrenheit.

On demand, the liquid from the hot tank — which is glowing white — would pass through a network of tubes that emit the light so that multijunction photovoltaic cells can convert it into electricity to be supplied to the grid. The cooled silicon would then be pumped back into the cool tank to repeat the process for the next cycle.