This Kyocera Solar Panel with 21Wp +15% -5% capacity is build with multicrystaline solar cells with over 16% efficiency. The panel has a 25 year limited warranty on power output. It measures 36.7 x 51.2 cm and weighs 2.0kg. With a 4-5kwh/m2 insolation it will deliver 340 kiloJoule/day = 90 watt-hours/day.