As of 2024, the world record for solar cell efficiency was 47. 6%, set in May 2022 by Fraunhofer ISE, with a III-V four-junction concentrating photovoltaic (CPV) cell. Advanced. The conversion efficiency of a photovoltaic (PV) cell, or solar cell, is the percentage of the solar energy shining on a PV device that is converted into usable electricity. That means they convert about one-fifth of sunlight into usable power. But efficiency is only part of the story. Real-world performance changes with temperature, shading, tilt. Quick Answer: In 2026, most residential solar panels installed in the UK operate at around 15–22% efficiency, with premium monocrystalline panels reaching approximately 23–24% under standard laboratory conditions.