Engineers have harnessed the abilities of both a solar cell and a battery in one device.

Scientists in the United States and Saudi Arabia have unveiled their new “solar flow battery”, which soaks up sunlight and efficiently stores it as chemical energy for later on-demand use.

The development could make electricity more accessible in remote regions of the world.

Practical solar energy systems convert sunlight to electrical energy, but it must be stored.

Normally this takes two devices - a solar cell and a battery - but the solar flow battery is designed to perform like both.

The solar flow battery has three different modes. If energy is needed right away, it can act like a solar cell and immediately convert sunlight to electricity. Otherwise, the device can soak up solar energy by day and store it as chemical energy to deliver it later as electricity when night falls or the sky grows cloudy.

The device can also be charged by electrical energy if needed, just like a typical battery.

The team's says its most recent solar flow battery model is able to store and deliver electricity from solar energy more efficiently than any other integrated device.

Research leader Professor Song Jin believes the solar flow battery could help transcend the limitations of the electrical grid by making electricity more readily available to people living in rural areas and providing an alternative source of energy when traditional electrical systems fail.

“These integrated solar flow batteries will be especially suitable as distributed and stand-alone solar energy conversion and storage systems in remote locations and enable practical off-grid electrification,” Prof Jin says.

Manufacturing current solar flow batteries is still too expensive for real-world markets, but Prof Jin believes simpler designs, cheaper solar cell materials, and technological advances could help cut costs in the future.

“We believe we could eventually get to 25% efficiency using emerging solar materials and new electrochemistry,” he said.

“At this efficiency range, without using the expensive solar cells, it should be quite competitive with other renewable energy technologies. Then I think commercialisation could be possible.”