Tag Archives: solar energy

Learning How Solar Cells Work

Summer is winding down and the kids are back in school, presumably learning some good stuff. But I always try to take advantage of good opportunities to teach my own kids a few things about science in general and solar energy in particular. Since it was a sunny morning, I pulled my son away from the computer, where he was busy on CheatsPulse looking up Adventure World cheats so that he could get a leg up on his friends in the game. That new Zynga game is taking up way too much of his time, but that’s another story altogether. He objected vehemently at first, hoping he good squeeze out a little more gaming time, but the promise of some ice cream after a short outdoor adventure lured him away.

I told him to bring along his calculator, and that got a few weird stares. My goal today was to teach him about photovoltaic cells, a key part of solar energy, and how they work to power some of the simplest electronic devices, such as his pocket calculator. Essentially, the photovoltaic cells have semiconductors inside, and when sunlight hits the cell, a portion of it is absorbed inside the semiconductor material. When this happens, electrons break free, providing the energy needed to power the simple calculator. Since it’s a cheap device, we decided to pry it open and take a closer look.

Surprisingly, he was very intrigued. There’s something about little boys and breaking things apart that just seems to work well. After a while, he had forgotten completely about his video games and we spent an enjoyable afternoon together out in the sun learning about how solar energy works. He didn’t forget the promise of ice cream, though, and about an hour later we were getting another lesson in the power of solar energy: it’s ability to melt ice cream very quickly.

And of course, soon after the experiment, he was back on the computer looking up some new Club Penguin cheats for his ongoing obsession with that game.

The Case for Solar Energy

Take a look up in the sky on a sunny day and you’ll witness the most amazing, powerful, and incredibly renewable source of energy known to man. The Sun. Of course, don’t stare directly at it or you’ll risk going blind. It’s just another reminder of how powerful the Sun really is.

As a species, we’ve been using solar energy for quite some time. Man has used it since ancient times to dry everything from clothing to animal hides. But we’ve been slow to adopt solar energy on a significant scale, primarily because in the 20th century, we lacked the technologies to efficiently capture and store it.

On a sunny day, each square meter on Earth receives approximately 160 watts of power from the sun over a 24 hour period. That means the entire planet receives about 84 terrawatts of power in a day. That’s a tremendous amount of power. Of course, we lack the means to capture and harness sunlight over every square meter of the globe, but you can quickly get a sense of solar energy’s potential.

The biggest obstacle to widespread adoption of solar energy is the relative inefficiency of converting raw sunlight to usable power. Solar technology has come a long way in just the last 20 years, but significant and costly obstacles remain preventing widespread adoption. Still, if you take the long view–something we should be doing a lot more of when it comes to energy and environmental issues–you’ll soon discover that solar energy is the best long-term solution for much our needs.

Think of it this way. Most of the inhabitants of our planet got along just fine for 4 billion years relying almost entirely on solar energy. Power and warmth from the sun was so important that our ancestors quite literally worshiped it, creating several gods who represented the power and life that the sun brought to their lives. I was reminded of this while my son was playing an adventure called Time Tangled Island on Poptropica. In this quest, you need to retrieve a piece of a sun stone mask belonging to an Aztec tribe. Huitzilopochtli, the Aztec sun god, was the most important god of all. He was the god who told the Aztecs where to build their city, and it was to him that human sacrifices were often made.

Can we adapt our approaches to energy consumption to do the same? The answer is yes and while the road to get there is long, it’s possible. We need smart and innovative approaches, an assessment of all the possible choices, and a well-thought action-plan to move to solar, but it’s possible and absolutely can be done.