Solar power: a space-time gift from the universe on your roof

The benefits that solar power provides are well documented; saving money, fixed electricity costs and lowering your global footprint.

Just the other day, I was reminded just how incredible the whole concept is by my two young boys who have a growing interest in science. “It’s just so amazing dad, why doesn’t everyone use it?” is their typical reaction.

So here are a few interesting facts about solar energy that we worked out:


The energy we get from solar panels is a result of an endless stream of photons bombarding the earth. They are elementary particles, which are present in the light that the sun gives off that have some quite amazing properties and just happen to be able to be absorbed by silicon really well. The modern concept and much of our understanding of photons comes from Albert Einstein.


With some inspiration from a science show, we did some calculations and realised an incredible fact about the photons that power our home. Because they are delivered by light, they are speedy little buggers. Photons travel from the sun to earth at an astonishing 1.07 billion kilometres per hour and take about 8 light minutes to cover the 149.6 million kilometre journey.


The conversation about light and speed inevitably gets pretty complex because time becomes a factor. Without getting into the quantum physics of it all another interesting thing we learned is that when you look out into space and see light, we are actually looking back in time, due to the massive distances involved. When we look at the moon for example, we are actually seeing what it looked like one second ago. When you look at that big beautiful sun that helps us power our homes we are actually seeing what it looked like 8 minutes ago.


Photons within the sun are created as part of the magic of space and the incredible thermonuclear reaction that is the sun. It’s a massive, broiling concoction of staggering proportions and although some photons are absorbed into its mass from space, some are also created internally as a by-product of the reaction.  We learned that photons tend to bounce around inside the mass of the sun for a very long time before they are randomly flung out to travel through space and land on our solar panels. Apparently, the average age of a photon is about 10 million years, so the bad news is they are decidedly second hand by the time we get them. The good news is, despite the fact they were created when dinosaurs roamed earth, they age really well.

So there you have it.

Solar power is not only abundant and a great low cost way to generate electricity, it’s also a fascinating gift from the universe that spans space and time; and it’s happening on your roof right now.

Top image credit: NASA/SDO (AIA) via Wikipedia

 © 2014 Solar Choice Pty Ltd

Nigel Morris