The photovoltaic (PV) process is how sunlight gets turned into electricity. Here’s how it works:
The basic unit of a solar panel is the PV cell. These cells are usually made from silicon, a material known as a semiconductor. The process starts when sunlight hits these cells.
- Absorption of Photons: Sunlight is made up of tiny energy packets called photons. When these photons hit the PV cells, they are absorbed into the semiconductor material.
- Excitation of Electrons: Absorbing the photons energizes the electrons in the silicon, causing them to break free from their atomic bonds.
- Electron Flow: Each PV cell has two layers of silicon, one positively charged (p-type) and the other negatively charged (n-type). The electric field created by these layers directs the movement of the free electrons, generating an electric current.
- Electricity Production: As these electrons flow, they create direct current (DC) electricity.
From Cell to Panel and Array
Solar panels are made up of many individual PV cells that are connected.
- A single PV cell typically produces only 1 to 2 watts of power.
- When multiple cells are connected, they form a solar panel (or module).
- The power output can be increased by combining several panels into a larger array.
Converting DC to AC
While solar panels generate direct current (DC), most household appliances and the power grid use alternating current (AC). To make the electricity usable:
- Inverters are used to convert the DC electricity from the solar panels into AC electricity.
- The AC electricity can then be used in homes, and businesses, or sent back into the power grid.
Efficiency and Progress
Over the years, the efficiency of solar panels has improved significantly.
- In the mid-1980s, commercial PV panels had an average efficiency of less than 10%.
- By 2015, this efficiency increased to around 15%.
- Today, the most advanced modules can reach about 25% efficiency.
- Experimental PV cells designed for special applications have achieved nearly 50% efficiency.
Applications and Benefits
Solar energy has a wide range of applications, from powering calculators to providing electricity to entire communities. The benefits of solar power include:
- Producing clean, renewable energy without harmful emissions.
- Reducing the carbon footprint and decreasing reliance on fossil fuels.
- Offering significant savings on electricity bills over time.
- Contributing to a more resilient and flexible energy grid.
As technology advances and costs decrease, solar energy is playing an increasingly important role in the global energy landscape. Photovoltaics, a simple yet powerful way to harness the sun’s energy, holds great promise for the future of renewable energy.
This post was written by Daniel Massaad, owner and expert solar technician at Energy Solutions Direct! ESD is one of the premier solar companies in Tampa! Our licensed and certified contractors are masters of their craft; with years of experience servicing the great Tampa Bay area and beyond, the choice is simple. ESD excels at offering you the best in solar value!
