Portable Concentrated Sunlight Power Supply Using 40% Efficient Solar Cells

Abstract

A novel portable concentrated sunlight electric generator is described. It consists of two 2 × 3 point-focus Fresnel lens parquets which focus sunlight onto 12 high-efficiency triple junction solar cells mounted on two aluminum-backed circuit boards. These lens parquets, along with a linear tracker drive, can be stowed in a case roughly the size of a notebook computer. The two aluminum circuit boards form the top and bottom of this case. For deployment, the case is open, the lenses pop up, and the unit will generate 50 W of electricity at 12 V. The unit is deployed with a manual tilt to the South and with an electronic drive rotation from East to West around the North to South tilt axis. In the spring and fall, the unit will track on sun throughout the day, and in the summer, it will stay on sun for 4 h before requiring manual readjustment. Soldiers, campers, hikers, and outbackers use more and more electronics today, and consequently, they carry heavy batteries. The unit that is described here can be carried in a backpack. This concentrated sunlight electric generator can also be useful as a concentrated photovoltaic demonstration tool in science classes.