Instructions: Given a passage and a query based on the passage, generate an unambiguous, concise and simple answer to the query from information in the passage. Note that the answer may not be present in exact form.
Input: A net energy meter keeps track of the all the power your solar system produces. Any solar energy that you do not use simultaneous with production will go back into the electrical grid through the meter. At night or on cloudy days, when your system is not producing more than your building needs, you will consume electricity from the grid as normal. Touted as a promising alternative energy source for decades, solar panels crown rooftops and roadside signs, and help keep spacecraft powered. But how do solar panels work? Simply put, a solar panel works by allowing photons, or particles of light, to knock electrons free from atoms, generating a flow of electricity. Solar panels actually comprise many, smaller units called photovoltaic cells. (Photovoltaic simply means they convert sunlight into electricity.) Many cells linked together make up a solar panel. Each photovoltaic cell is basically a sandwich made up of two slices of semi-conducting material, usually silicon — the same stuff used in microelectronics. To work, photovoltaic cells need to establish an electric field. In addition, the nation’s solar capacity by the end of 2016 is projected to be double what it was at the beginning of 2015, while costs continue to decline and panel efficiencies increase. The question many people have is: How exactly do those panels work? The diagram above illustrates the operation of a basic photovoltaic cell, also called a solar cell. Solar cells are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. What's the biggest difference between how a plant captures light energy and how we do it with solar cells? We wish we could do what plants do because plants absorb the light, and [they use] that electron to change a chemical bond inside the plant to actually make fuel. Could you do artificial photosynthesis and emulate a plant? We would love to be able to make a solar cell that instead of making electricity makes fuel. That would be a very big advance. Solar panel conversion efficiency, typically in the 20% range, is reduced by dust, grime, pollen, and other particulates that accumulate on the solar panel. Solar photovoltaic (PV) panels are based on a high-tech but remarkably simple technology that converts sunlight directly to electricity < PREVIOUS: The Solar Resource | NEXT: Rooftop Solar Panels > It's an idea that has been around for well over a century. Sun Activation. 1  Photons bombard and penetrate the cell. 2  They activate electrons, knocking them loose in both silicon layers. 3  Some electrons in the bottom layer sling-shot to the top of the cell. 4  These electrons flow into metal contacts as electricity, moving into a circuit throughout a 60-cell module. How Solar Panels Work How a PV cell makes electricity Under the sun, a photovoltaic cell acts as a photosensitive diode that instantaneously converts light – but not heat – into electricity. Basic Steps in Solar Energy Generation and Transmission. 1  Sunlight hits the solar panels, and creates an electric field. 2  The electricity generated flows to the edge of the panel, and into a conductive wire. 3  The conductive wire brings the electricity to the inverter, where it is transformed from DC electricity to AC, which is used to power buildings. Query: how does solar panel work
Output:
A solar panel works by allowing photons, or particles of light, to knock electrons free from atoms, generating a flow of electricity.