Ars Technica reports on an international team’s demonstration of a device merging photovoltaic and battery hardware into a single, unified device “that can have extensive storage capacity… a device that’s both stable and has efficiencies competitive with those of silicon panels.”
The resulting hardware can operate in any of three modes: providing power as a solar cell, using sunlight to charge as a battery, or providing power as a battery.
Previous records for a solar flow battery show the tradeoffs these devices have faced. The researchers used a measure of efficiency termed solar-to-output electricity efficiency, or SOEE. The most efficient solar flow devices had hit 14.1 percent but had short lifespans due to reactions between the battery and photovoltaic materials. More stable ones, which had lifespans exceeding 200 hours, only had SOEEs in the area of 5 to 6 percent.
The new material had an SOEE in the area of 21 percent — about the same as solar cells already on the market, and not too far off the efficiency of the photovoltaic hardware of the device on its own. And their performance was stable for over 400 charge/discharge cycles, which means for at least 500 hours. While they might eventually decay, there was no indication of that happening over the time they were tested. Both of those are very, very significant improvements.
The article ends by suggesting this demonstration means researchers can now look for more stable battery and photovoltaic chemistries with improved efficiencies. “Whether all of that is compatible with low cost and mass production will be the critical question. But, at this stage of the renewable energy revolution, having more options to explore can only be a good thing.”
Read more of this story at Slashdot.