Solar Power: The Key to a Clean Future

How Does Solar Power Work?

Solar power is produced by capturing the sun’s energy and converting that energy into usable electricity for your home.

Every hour of every day, energy from our sun, in the form of photons, impacts the Earth with enough solar power to meet our current energy needs for an entire year.

What are photons?

In physics, a photon is a bundle of electromagnetic energy. It is the basic unit that makes up all light. The photon is sometimes referred to as a "quantum" of electromagnetic energy. Photons are not thought to be made up of smaller particles. They are a basic unit of nature called an elementary particle.

What is Photovoltaic Power?

Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, the most common of these materials being silicon. PV gets its name from the process of converting light (photons) to electricity (voltage), which is called the PV effect.

The PV effect was discovered in 1954, when scientists at Bell Telephone discovered that silicon (an element found in sand) created an electric charge when exposed to sunlight. Soon solar cells were being used to power space satellites and smaller items like calculators and watches.

How are Photovoltaic Solar Panels Made?

Photovoltaic (PV) solar panels are made up of many solar cells. Solar cells are made of silicon, like semiconductors. They are constructed with a positive layer and negative layer, which together create an electric field, just like in a battery.

How do Solar Panels Work?

When photons hit a solar cell, they knock electrons loose from their atoms. If conductors are attached to the positive and negative sides of a cell, it forms an electrical circuit. When electrons flow through such a circuit, they generate electricity. Multiple cells make up a solar panel, and multiple panels (modules) can be wired together to form a solar array. The more panels you can deploy, the more energy you can expect to generate.

PV solar panels generate direct current (DC) electricity. With DC electricity, electrons flow in one direction around a circuit. Since the US power grid is powered by AC electricity, this DC current must be converted to AC with the use of an inverter. AC electricity was chosen for the U.S. electrical power grid, primarily because it is less expensive to transmit over long distances.

What Does a Solar Inverter Do?

A solar inverter takes the DC electricity from the solar array and uses that to create AC electricity. Inverters are like the brains of the system. Along with inverting DC to AC power, they also provide ground fault protection and system stats, including voltage and current on AC and DC circuits, energy production and maximum power point tracking.

How Does a Solar Panel System Work?

First, sunlight hits solar panels on your roof. The panels convert the energy to DC current, which flows to an inverter. The inverter converts the electricity from DC to AC, which you can then use to power your home. It’s beautifully simple and clean, and it’s getting more efficient and affordable all the time.

A typical grid-tied PV system, during peak daylight hours, frequently produces more energy than one customer needs, so that excess energy is fed back into the grid for use elsewhere. The customer gets credit for the excess energy produced, and can use that credit to draw from the conventional grid at night or on cloudy days. A net meter records the energy sent compared to the energy received from the grid.

Learn more about net metering in Virginia here.