We’ve all used calculators with solar cells powering them. These devices never require any battery power and don’t even need to be turned off. Providing there’s enough light, they just go on and on, working day to day, week to week. Perhaps you’ve also noticed larger solar panels. Emergency road signs for example. Many street lights are powered by solar these days too. These lights contain batteries which charge in daytime when sunlight shines on the solar cells. During the night, a photoresistor then detects little to no light availability and a circuit board then triggers batteries to power LED lights.
Photovoltaics (photo means light, voltaic means electricity) are now used in much less exotic ways than previously when they were utilized almost exclusively in space to power electrical systems within satellites.
On a bright sunny day, the sun produces approximately 1,000 watts of energy for every square meter of our planet’s surface. Should we be able to harness that amount of energy, we’d be able to power our homes and businesses entirely free of charge.
Here, we will examine solar cells and solar panels and learn exactly how they convert energy from the sun into electricity.
Without getting overly technical with regards to how electricity is produced, let’s focus on the provision of a basic explanation of how solar panels work in order to produce power in the way they do.
Firstly solar panels harness solar energy from the sun in individual solar cells. The energy is then transferred to an inverter which converts it to electricity, suitable for use in your home.
A semiconductor material such as silicon absorbs particles of light when the sun shines on the photovoltaic cells (PV cells) within solar panels. Particles of electricity (electrons) which are negatively charged, begin to flow through the solar cells in a single direction, which means that a current is created. The solar panels are constructed from a series of interconnected cells.
Solar panels create direct current (DC) electricity. Our homes do not run on DC power, they run on AC, and this is what makes a solar inverter necessary. The inverter changes DC to AC or alternating current. Any excess AC which is not used is sent to the electric grid and is then credited to your account, providing your utility company offers this facility - most utility companies in Massachusetts do.
Nevertheless, if you prefer to live completely free of the grid, you can if you so wish use a backup generator should your solar supplies be running low. There is an alternative however. The second stand-alone system can come from batteries. Batteries though can add a hefty price and take a lot of maintenance.
The alternative as mentioned is to connect your home to the utility grid. This way, you can purchase power as and when you require it, and sell it back when your system is producing an excess amount to what you require. Do keep in mind though that your own utility company may not be required to participate in this business model and buyback price vary rather a lot from provider to provider. Further, special equipment is needed in order to ensure that the power you have is compatible to the utility company.