Over the past two centuries, humans learned how to harness fossil fuels on a vast scale to power an industrial revolution, but at what cost? The benefits come at great, mounting, and irreparable environmental costs. Fossil fuels cannot continue to be humanity’s primary source of energy. Our dependence on international oil must stop. As Thomas Edison said back in 1931:
“We are like tenant farmers chopping down the fence around our house for fuel when we should be using nature’s inexhaustible sources of energy — sun, wind and tide. … I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.”
It’s time for a solar revolution now. The sun has been fueling life on earth for centuries so it makes you wonder how we’ve come to place such an emphasis on oil when the sun’s energy is so abundant. Simply (and matter-of-factly), the earth receives enough solar radiation in one single hour to supply the planet’s electrical needs for a whole year! So how do we convert this obscene amount of energy? Let’s explore this further…
At US Solar Institute, our class names start with PV (i.e. PV-201, PV-301, & PV-401). What does PV mean? PV stands for photovoltaic which comes from the words photo, meaning light, and volt, meaning electricity. In short, the term PV means electricity from light. PV cells are built on wafers of silicon made from ordinary sand and quartz. Once assembled into solar panels and exposed to the sun, the cells directly convert light into electricity (or direct current, DC)—without polluting emissions or moving parts.
So how does it really work? The sun’s rays hit the silicon panels and convert that energy in a DC voltage which run through copper wires into an inverter, which converts the DC power into AC (alternating current). The result is electricity to power your household appliances–all with the power of the sun.
From the inverter, the solar-generated power feeds into circuitry of a household and onto the regions electrical grid. A remote, or independent, power system can also form a self-contained circuit without connecting to the grid, but these off-grid systems require batteries to store power.
If we haven’t lost you yet, here are some solar terms you may have never heard of…
- Photon: Solar radiation arrives on the surface of photovoltaic cells in the form of photons, providing the main energy that activates cells to produce energy.
- Module: Solar panels are called modules because they link together evenly and interchangeably use electrical connectors to form a circuit within an array, with a building or a utility grid. To make a module, cell-matrix laminants are mounted into sturdy aluminum frames. The resulting module is robust enough to withstand 50MPH hailstone impacts and up to 112lbs per square foot of wind or snow!
- Conversion efficiency: This measure gauges the percentage of solar (light) power reaching a panel that is converted into electrical power. Conventional cells now range in the high percentage teens (13-18%).
- Insolation: Sunlight varies by region. Insolation is a measure of the solar radiation energy in a given region. It is usually expressed as the intensity of light energy per unit of land area. As a whole, the U.S., particularly the Southwest and Southeast, offer strong insolation. On the other hand, Germany, the solar leader, barely gets more sun than Alaska. Policy dictates results!
Clearly, converting the sun’s rays into electricity we can use and rely on is not as simplistic as some people may believe. For those of you interested in going solar or off-grid, starting your own solar business, or working in the solar industry, a certain amount of knowledge and training is highly recommended. We always tell our potential students and our existing students will echo the same: “You don’t know what you don’t know before you’ve stepped into a class.” Whether you’re curious about the solar industry or are a seasoned solar professional, US Solar Institute can give you the real world, hands on tools you’ll need to have a true understanding of how to harness the sun’s abundance of energy. The time for a solar revolution is now.
Source: Energy for You & Me
