The Low Down On Solar

Tom Jacobs
Jul 30, 2017 · 2 min read

So, solar power is pretty cool. Free electricity. From thin air. Sounds like a good deal. So let’s learn some things today.

Pop quiz: What’s the best efficiency you can get from a solar panel? How much of the Sun’s energy that hits the panel can we turn into electricity? 80%? 90%?

It’s 24%.

Usually it’s around 15% for reasonably priced ones. All that sunlight, going to waste!

There are three basic different types of solar panels: Monocrystaline, Polycrystalline, and Thin Film. (Plus there’s the non-electric ones which are basically reverse water radiators.)

Next question: Why do the cells themselves in the panel often have that distinctive corners-cut-square shape?

Because that’s the way to get the most out of the big cylinder ingots:

Wait, what’s an ingot?

This. For sale on eBay. Seriously.

It’s a big cylinder of silicon, grown like a stalagmite.

What sort of voltage do they give?

Each cell gives you about half a volt. So you gotta put a bunch together in series to pump the voltage up to 12v or 24v, and then put those in parallel to pump up the amperage. And things get tricky when there’s shade.

How many houses in Australia have solar panels on their roof?

Guess what! We lead the world in this: 15%. That’s pretty, pretty, preeetty good.

Future questions to ponder:

Can I sell my energy back to the grid?

Why do they only pay me a quarter of the price I pay them?

Why did so many solar companies collapse over the last 10 years?

Why aren’t we all using free electricity all the time?

How much sun do I need each day to power my home?

Is it the sun’s light or heat that we get the power from?

Why are so many bulky heavy ugly electronics involved?

A large solar array I saw near Uluru. Fenced off to keep the Kangaroos from sun-baking.

Australian Robotics Society

The Australian Robotics Society is a community of robot builders.

Tom Jacobs

Written by

Making robots.

Australian Robotics Society

The Australian Robotics Society is a community of robot builders.

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