Short answers, pulled from the story.
A photovoltaic system uses solar cells to convert photons directly into direct current electricity. Multiple cells are wired together in a module, modules are linked into arrays, and an inverter converts the direct current to alternating current suitable for home or grid use. As of 2019, state-of-the-art inverters reached more than 98 percent conversion efficiency.
Shading has a disproportionate effect on PV output because cells are wired in series. A single shaded cell can drop 8 volts instead of contributing 0.5 volts, effectively absorbing the power produced by 16 other cells in the string. Bypass diodes limit this damage by rerouting current around the shaded section.
A PV system recoups the energy used in its manufacture in about 2 years under typical conditions. In exceptionally sunny locations, or when thin-film technology is used, that energy payback time drops to one year or less. Module lifespans typically reach 25 years or more.
Single-axis trackers increase total power production by about 20-25 percent compared to fixed-mounted systems. Dual-axis trackers can push that gain to 30 percent or more, depending on latitude. In some configurations with sensors and optimizers, viable output can increase by up to 45 percent.
Soiling is the accumulation of dust, dirt, snow, or other material on panel surfaces that reduces the light reaching the cells. In 2018, the global annual energy loss from soiling was estimated at a minimum of 3-4 percent, with an estimated revenue loss of between 5 and 7 billion euros. One study from Ontario found that cleaning flat-mounted panels after 15 months increased output by almost 100 percent.
Solar PV modules account for less than half of a photovoltaic system's overall cost. The remainder covers balance-of-system components such as inverters, mounting hardware, and cabling, as well as soft costs including permitting, inspection, installation labor, and financing.