With the heavy production of greenhouse gases through conventional energy sources, solar energy has become incredibly important in our society. Solar Energy has the potential to reduce greenhouse gas emissions that contribute to global warming and move towards a brighter, cleaner future.
Solar panels do not require fossil fuels and instead convert the sun’s energy into electricity. The figure below describes how solar energy can be used to power our homes.
Renewable Energy 101: Solar Power
The basic steps in the operation of a solar system are:
The solar panels on the roof collect and convert light into electricity
Inverter changes direct-current (DC) electricity into alternating current (AC) electricity
Electricity passes to Breaker box (main power source for the house)
Breaker then splits power into different outlets in the house
Most houses with solar systems are also connected to the grid (not shown here).
To dive a little deeper into exactly how a solar panel works, we look at a solar cell. The solar cell is made up of semiconducting material with impurities added to the front and the back to create an electric field. Once the rays of the sun strike the cell, electrons gain the energy needed to move freely and move towards the n-type semiconductor. When a load, an electrical component that consumes electric power, is connected, the electrical energy from the solar cell powers the electrical component. Below, a figure of a solar cell is provided, and the process is shown through four steps.
As mentioned in the previous paragraph a solar panel consists of numerous solar cells. When sunshine shines on a solar cell the front and back become positively and negatively charged. This is important because it provides the voltage to drive current through a circuit. Wires are connected to the positive end and to the negative end of the cell. When looking at a solar panel, the solar cells seem to be connected through the middle directly, but it actually follows the positive to negative pattern as seen in the Figure 1. A way to imagine it is like a wave, going from top to bottom. For these solar cells, it will be connected together in a series. A series is a circuit where electrons flow in one direction. From these, when every solar cell is connected with each other, as a series, it finally becomes a solar panel. In the end, Figure 2 is what a solar panel should look like. Schematic exaggerates length of wires between solar cells. It should also be noted that some solar cells have different connection schemes.
*NOTE: Figures 1 & 2 are in aerial view and the blue squares represent solar cells and their connections to demonstrate how they function in series. They are not to scale. Figure 3 is an actual single solar cell.
Figure 4 is an image of a realistic solar panel and represents Figure 2 in a realistic manner. As you can see, the cells are adjacent to one another.
Figure 3 Figure 4
