As concern for the environment rises among individuals and communities, people increasingly turn to affordable and stylish energy alternatives. Solar lights are an easy option to try, but how do solar lights work? Using the best solar lights helps with illuminating homes, gardens, walkways, and streets while remaining energy conscious. While they are a popular environmental option and delightful design opportunity, they also allow for you to have an interesting piece of science in your home that harnesses the power of sunlight without any need for wires or separate batteries.
Solar Light Components
Solar lights depend on photovoltaic cells, more commonly known as solar cells, which convert light energy from the sun into usable electrical energy. Solar cells are made of a combination of chemicals and a semiconductor. Semiconductors do not conduct electricity as well as a conductor like metal, but they conduct electricity better than nonconductors like wood. Silicon crystals are popular semiconductors used in solar cells.
The solar cell connects to a diode that keeps any electrical current from flowing back to the cell instead of into the battery. The diode connects the solar cell to the battery, and then the battery stores all of the energy the cell generates throughout the day to be used later, usually at night either indoors or outdoors.
The solar cell and battery link to a control board that dictates when the solar light stops charging and instead flickers on for the night. The control board detects if sunlight is still present through a photoreceptor, and once sunlight no longer reaches the photoreceptor, the control board turns on the LED, short for light-emitting diode, using the power stored in the battery. The LED illuminates the space by consuming the battery power that was generated by sunlight, and then once the photoreceptor senses sunlight once more, it turns off and begins charging again to prepare for the next time the photoreceptor senses darkness. The cycle continues for as long as the technology in the light works and the sun continues to shine.
How Do Solar Lights Work?
The chemistry and technology that go into each solar light depend on the physical principles of subatomic particles like electrons, the negatively charged particles that flow to produce electricity. As a pure element, silicon has 14 electrons with four of those electrons existing on its incomplete outer electron shell. The silicon atoms bond with other silicon atoms to fill their outer shells with eight electrons and therefore complete each electron shell. However, in solar cells, the silicon crystals have intentional impurities mixed in to disrupt the perfect bonds the atoms create. This disruption frees up electrons to flow. When light interacts with the surface of a semiconductor, like an impure silicon crystal, the energy of the sunbeam activates the unbonded electrons, which then interact with protons, the positively-charged counterpart to electrons. The positive field created by the protons facilitates the movement of the freed electrons along the circuit to the diode and then the battery, which ultimately stores power for the light.
Other Uses for Solar Cells
Using sunlight to generate electricity is a great type of clean energy that harnesses a free, renewable resource. Electricity generated by sunlight can be applied in a variety of ways, and solar cells come in many different sizes to power many different types of technology, not just lights. A calculator is a common solar-powered device with a small row of solar cells. Solar cells are also used to power hiking watches while an adventurer braves the wild without access to traditional power sources. Solar-powered fixtures also add a unique aesthetic to any space and can be one of the best gifts for gardeners. When solar cells group together, they form a module, which can be framed to create a solar panel. Solar panels power buildings and equipment, but they can also power technology in space, like the satellites that orbit the earth, without human intervention.
Solar lights use amazing scientific principles to function, and they demonstrate on a small scale how using clean energy can be easy, efficient, and cost-effective. They help make a space warmer and more inviting without the worry of batteries or plugs, and they provide a great conversation topic of how they convert energy to light. Solar lights signal the beginning of integrating better energy practices into our homes–one day, all of our lights might be solar powered!