We’ve all seen them, or maybe you haven’t yet. You’ll come across your first solar panel soon enough, since according to Forbes (The Future Of US Solar Is Bright (forbes.com) and other financial reporters, the solar energy industry is growing at a steady clip as demand for clean power increases. As this alternative method of power becomes more ubiquitous, you’ll see large black, blue or dark gray panels in fields, on roofs, or anywhere the sun shines regularly and brightly enough to convert solar light into energy. But just what are those panels made of and how does it work? These panels are made mostly of silicon, glass, and metal. This post goes into how each of those components plays a part in converting solar light into usable energy.
Silicon: Abundant and Helpful
Solar panels are constructed by creating photovoltaic cells made of silicon, the second most common element on the Earth and one that naturally converts sunlight to electricity. This abundant element can be grown in a laboratory into shapes conducive to creating thin silicon wafers. Silicon is the most widely used material because of its abundance, but efforts at developing more efficient and better energy production have produced other alternatives, including cadmium telluride, copper indium gallium selenide solar cells, and a non-crystalline form of silicon.
Silicon Wafers
There are two variations of silicon involved in the sandwich of materials that make up solar panels. These are P-type and N-type. P-type silicon is treated with phosphorus or boron to make it a semiconductor. Wafers of these materials are sandwiched between a conductive metal sheet and a layer of glass that protects the surface but also helps with light by acting as a lens to draw light inward without reflecting it away from the panel. The P-type and N-type silicon act together to convert the energy received from the sun through the non-reflective glass covering and transfer it to the power grid via the conductive metal elements in the solar cell.
Thin-Film Solar Cells
The process described above using wafers is the more traditional and common practice for the construction of solar panels, but innovation means manufacturing has found other ways to produce more efficient solar panels for commercial use. Thin-film solar cells are becoming more popular, so-called due to how flexible and light the cells are.
Conductive Metal
When you look at a solar panel, you’ll notice lines running across the dark surface of each cell. These are actually metal contacts that provide a conduit for the electricity to run through once it is captured and converted by the silicon. Conductive metals are also used underneath the layers of silicon to create the field in which electricity flows in the solar cell.
Solar Inverter
Each solar panel usually has an inverter. This electric device converts energy from direct current to alternating current and feeds that power into the grid. These may also be used to help balance the operation of the solar panel, provide tracking information, and more to the operator of the solar panel.
Solar Modules
The panels themselves are made up of dozens of solar cells as described here. The cells are connected but kept separate so that each cell can be corrected should issues arise. These cells are mounted in what’s commonly called a panel but can also correctly be called a module. Modules or panels are connected to create a grid the size of which depends on the need for electricity. Some solar farms provide power for nearby cities with thousands of solar panels, while other businesses may keep less than a hundred on their roofs to help with utility costs.
